Learning about Exposure - The Exposure Triangle

Learning about Exposure – The Exposure Triangle


Bryan Peterson has written a book titled Understanding Exposure which is a highly recommended read if you’re wanting to venture out of the Auto mode on your digital camera and experiment with it’s manual settings.

In it Bryan illustrates the three main elements that need to be considered when playing around with exposure by calling them ‘the exposure triangle’.

Each of the three aspects of the triangle relate to light and how it enters and interacts with the camera.

The three elements are:

  1. ISO – the measure of a digital camera sensor’s sensitivity to light
  2. Aperture – the size of the opening in the lens when a picture is taken
  3. Shutter Speed – the amount of time that the shutter is open

It is at the intersection of these three elements that an image’s exposure is worked out.

Most importantly – a change in one of the elements will impact the others. This means that you can never really isolate just one of the elements alone but always need to have the others in the back of your mind.

3 Metaphors for understanding the digital photography exposure triangle:

Many people describe the relationship between ISO, Aperture and Shutter Speed using different metaphors to help us get our heads around it. Let me share three. A quick word of warning first though – like most metaphors – these are far from perfect and are just for illustrative purposes:


The Window

Imagine your camera is like a window with shutters that open and close.

Aperture is the size of the window. If it’s bigger more light gets through and the room is brighter.

Shutter Speed is the amount of time that the shutters of the window are open. The longer you leave them open the more that comes in.

Now imagine that you’re inside the room and are wearing sunglasses (hopefully this isn’t too much of a stretch). Your eyes become desensitized to the light that comes in (it’s like a low ISO).

There are a number of ways of increasing the amount of light in the room (or at least how much it seems that there is. You could increase the time that the shutters are open (decrease shutter speed), you could increase the size of the window (increase aperture) or you could take off your sunglasses (make the ISO larger).

Ok – it’s not the perfect illustration – but you get the idea.



Another way that a friend recently shared with me is to think about digital camera exposure as being like getting a sun tan.

Now getting a suntan is something I always wanted growing up – but unfortunately being very fair skinned it was something that I never really achieved. All I did was get burnt when I went out into the sun. In a sense your skin type is like an ISO rating. Some people are more sensitive to the sun than others.

Shutter speed in this metaphor is like the length of time you spend out in the sun. The longer you spend in the sun the increased chances of you getting a tan (of course spending too long in the sun can mean being over exposed).

Aperture is like sunscreen which you apply to your skin. Sunscreen blocks the sun at different rates depending upon it’s strength. Apply a high strength sunscreen and you decrease the amount of sunlight that gets through – and as a result even a person with highly sensitive skin can spend more time in the sun (ie decrease the Aperture and you can slow down shutter speed and/or decrease ISO).

As I’ve said – neither metaphor is perfect but both illustrate the interconnectedness of shutter speed, aperture and ISO on your digital camera.

Update: A third metaphor that I’ve heard used is the Garden Hose (the width of the hose is aperture, the length that the hose is left on is shutter speed and the pressure of the water (the speed it gets through) is ISO.

Bringing It All Together

Mastering the art of exposure is something that takes a lot of practice. In many ways it’s a juggling act and even the most experienced photographers experiment and tweak their settings as they go. Keep in mind that changing each element not only impacts the exposure of the image but each one also has an impact upon other aspects of it (ie changing aperture changes depth of field, changing ISO changes the graininess of a shot and changing shutter speed impacts how motion is captured).

The great thing about digital cameras is that they are the ideal testing bed for learning about exposure. You can take as many shots as you like at no cost and they not only allow you to shoot in Auto mode and Manual mode – but also generally have semi-automatic modes like aperture priority and shutter priority modes which allow you to make decisions about one or two elements of the triangle and let the camera handle the other elements.

A lot more can be said about each of the three elements in the exposure triangle. Check out other relevant posts on the topic at:

  1. ISO
  2. Aperture
  3. Shutter Speed

Note: this post has been updated since its original posting and republished for 2011.

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Darren Rowse is the editor and founder of Digital Photography School and SnapnDeals. He lives in Melbourne Australia and is also the editor of the ProBlogger Blog Tips. Follow him on Instagram, on Twitter at @digitalPS or on Google+.

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  • Les White February 27, 2013 02:31 am

    Petersen's book is one of the most important photography books I have read--his explanation of principles of exposure combined with his photos and camera settings is excellent (he also has a great book on composition!) Your conclusion about bringing it all together gets it right in terms of constantly juggling three moving pieces of ISO, aperture and shutter speed as i have found out doing lots of low light sunset/sunrise photography

  • Andy February 13, 2013 02:30 am

    Thanks for posting Darren, as a budding photographer my knowledge of exposure is now much clearer. The use of metaphors really helped especially the sunbaking analogy. I do agree with what Marilyn said as well because without understanding the camera fundamentals then the photos you take will not have best exposure.

  • Carolyn shaw February 11, 2013 06:49 pm

    Had A Fujifilm Fine pix HS30exr for Christmas as wanted to start taking and learning about better photos
    I couldn't understand the technology re: F numbers Shutter speed,, iOS, aargh. But
    Having found this site yesterday it all became much clearer, loved the window metaphor! feel I can now move on understanding more things can't wait for the next tips THANKYOU Carolyn

  • Rhonda January 26, 2013 12:14 am

    This may sound stupid. But, I am a beginner, and although I understand the concept of each element individually. I cannot wrap my mind around bringing all three together. I have been using manual for all my shots, and use my exposure compensation meter, I check WB.....everything. They still are not coming out to my satisfaction.

  • Tung December 29, 2012 09:24 am

    Think harder, nuf. If you can!

  • nuf December 26, 2012 07:01 am

    terrible "explanation"

  • Tung December 16, 2012 08:24 am

    I have another metaphor for exposure: painting on a wall (amount of paint on the wall is amount of light absorbed by the camera sensor)
    - Aperture: the size of the brush, bigger brush allows you to put more paint on the wall.
    - Shutter speed: longer you paint, more paint you put on the wall
    - ISO: how sensitive the wall is to the paint, smoother wall absorbs less paint, rough wall absorbs more paint. High ISO means the wall is rougher (grainier).
    This metaphor can also help explain DOF: smaller brush (smaller aperture) allows you to paint more crevices, dents on the wall, meaning more DOF.

  • Carol November 9, 2012 01:53 am

    With the exposure triangle and the other examples, now I can fully understand the differences.

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    Thanks for the Info, now i understand my note camera options, let's hope that the photos gets better :D

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  • Ashley D'souza August 26, 2012 06:03 am

    Hi I've just started with photography, so please bare with me. I did not understand the part where you say

    'decrease the Aperture and you can slow down shutter speed and/or decrease ISO'

    If you are decreasing the aperture less light is coming in, so for the required light to come in we slow down the shutter speed is fine. But about the ISO aren't we supposed to increase the ISO for the image to become more bright. The reason I have this doubt is because you use 'and / or'. If it is 'and' I get it because you can decrease the shutter speed to such an extent that we can decrease the ISO to get the desired photo. But if you say 'or' then on decreasing the aperture you will have to increase the ISO.

  • Onelifethislife August 4, 2012 10:39 pm

    This a great article. The best metaphor was the window. It took me a while understand the relationships between the three. Thanks!!!

  • retech son May 23, 2012 11:56 pm

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  • Buddy May 10, 2012 11:13 pm

    The window analogy is brilliant!

  • Craftwhack April 7, 2012 06:27 am

    I read your Pro blogger blog, but keep forgetting you have this one- I've been unsuccessfully searching for a clear explanation on the mighty triangle of photography and this one explanation finally helped it sink in (window analogy. I'm team window.) Thanks!

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  • Michelle Wagoner March 13, 2012 04:55 pm

    i loved the article. Thank you. I just taught a Photography Merit badge class and used a cooking metaphor for them to use. If ok, i will include this one the next time i teach it.

  • Juan fez head editor February 20, 2012 11:49 pm

    I just got back into photography after 14 years away from it. I have 3 photographers trying to cover all the functions of our Shriner Center and I decided to get a camera to help them out because we were missing a lot of photo ops during the year due to lack of coverage. I got my dslr last week and shot almost 20 gigs this last weekend at a 3 day special function in our Shriner Center. Your articles have made my return behind the camera a lot easier by refreshing my memory with the skills I had not used in way too many years. I may even be able to use some of my pictures in our April issue of our magazine. Thanks for re-opening my mind and helping me feel comfortable behind the lens again.

  • John February 12, 2012 05:22 am

    .... I`ll have a pint of what ` Peatantics ` ( Jan 27th 2012 ) has ben drinking.

  • Pam January 31, 2012 05:53 pm

    i love the example with the window it really help me a lot to actually understand the job of each one of them.... thanks..

  • peatantics January 27, 2012 02:19 pm

    Size of the chicken is the ISO/ASA or the sensitivity.
    Ha HUM, metaphor where would we bee without one?
    Time it is cooked for is that shutter speeds property.
    Windows, Sunbaker and Hoses what about the oven?
    Temperature is aperture setting in figurative actuality.

    Double or half the weight family hungry, starving cook.
    Lable is the f chook system table by chook-a-maticians?
    Double of half the time of cooking don't burn our chook.
    Have you never seen a three legged crook old Manxians?
    Double or half of the temperature better take another look.

    In principle we have established a triplet as one superb.
    For the f chook principle forms every oven of possibilities
    Cross over to chook cooking endeavors road of suburb.
    Double or half the money as you bet on these probabilities.

  • Erin January 27, 2012 08:03 am

    I loved this article. A great metaphor for how they all interact

  • John January 26, 2012 08:52 pm

    Personally,, I think the article is great, and the triangle Metaphors even better.

    Obviously , Michael ( May 18th 2010 ) knows everything there is to know about everything, and is too critical.

    For all us beginners who dont know, then i think the Metaphors do the job and explain things in OUR launguage.
    The clue is in the title ..... " LEARNING about exposure "

    Thanks Darren.

  • Donna January 15, 2012 05:52 am

    Love learning from your site. Thanks

  • White Petal Wedding Photography January 11, 2012 05:18 am

    What a great little article, hadn't thought of it in this triangular fashion before, but that simple depiction will stick in my mind. Thanks.

  • Gerty January 11, 2012 12:22 am

    Thanks for the tips! So glad it's explained this way. I'm sure I am not the only visual (and clueless!) learner to ever own a dslr. It's given me the confidence to step out my comfy auto zone and explore a bit.

  • Lisa December 23, 2011 10:56 am

    Ok I still love this. It definitely made sense for me. Too many people are over complicating it. haha. But that being said, Thank you again, and all of you for your feedback. Every bit counts!

  • Jamz December 22, 2011 07:07 am

    Oh yeah and if you are a strobist, that triangle becomes a square because you have to also take into account the amount of light from your strobe and the "inverse square law" that can affect the lighting in your images.

  • Erik Kerstenbeck December 19, 2011 04:46 am


    Interesting article indeed - thanks for sharing! I am old school, so when I began there were no In Camera meters, in fact I used The Sunny 16 Rule for my totally Manual Nikon (Yes, dedicated Nikon user). Then I borrowed my Dad's hand held Light Meter and really learned what all this stuff means. I would suggest to find someone with a handheld "antique" and try seeing what it sees and study the relationship between shutter, aperture and ISO.

    Then go to a beach like this one and just have fun shooting and experimenting!


  • Jeffrey Kaplan December 18, 2011 06:01 am

    I think this article is a good start, but it doesn't say WHY you would want to care about these settings. Without the WHY, who would really care about the what? A factor I was very careful to illustrate when I gave a talk about this subject (which I called the "Exposure Tripod", likening the three "legs" of the exposure to the device used to hold a camera hands-free) to my camera club. And that why being primarily the ability to control focal and motion blur.

  • raghavendra December 18, 2011 03:12 am

    This is a must know article for all photographers


  • Trevon December 18, 2011 02:42 am

    Alan, it's technically not for free.

    Ha makes over 20,000$ a month in ad traffic because people look at his articles with ads.

  • Barry E.Warren December 18, 2011 02:13 am

    This was Great!!! loved how the triangle was explained with metaphors.

  • Average Joe December 18, 2011 01:54 am

    I've recently been trying to test all of these things out myself, but this article was so much more helpful than me trying to wrap my mind around it alone. Much appreciated. Thanks Darren!

  • Jay December 10, 2011 09:45 pm

    I had been always confused with exposure attributes. This article really helps understanding it. Specially, the shutter explanation confirmed my assumption on motion.

  • Sam December 6, 2011 06:50 am

    Thanks for these metaphors... The window one really helped me. I've been in a photography class and the way these were explained to me completely confused me. This makes much more sense :)

  • John Afravi November 16, 2011 04:44 am

    A "quadrangle? Really? C'mon guys. It's called a SQUARE or even a RECTANGLE if you want. And the angle of it has nothing to do with this matter. You're pointing out 4 points in a service aspect.

    But all in all, it's wrong. Filters and other accessories have nothing to do with the exposure triangle. That's a whole other thing in itself....

    Photographers......always over analyzing. :P

  • Marco Rossi September 28, 2011 10:29 pm

    Thank you for your interesting tutorial!

  • Othmane Bekkari September 23, 2011 12:53 am

    Very interesting article, and the analogies are very illustrative.
    Talking about illustrations, I have included in my article on the exposure triangle an illustration which, to my belief, is quite representative of the exposure triangle, as it dos not only use the fact that there are three variables, but it also illustrates the interactions of the three: as you pull one of the corners of the triangle away from the center, you are automatically pulling one or both of the variables closer to the center.

    What do you think?

  • Alan September 16, 2011 08:10 am

    Excellent article, great analogy, cutting the 'techno-speak' down to 'plain-speak' i like it, the window one is the best, and for those that are so picky about the sunglasses thing making it a quadrangle, why don't you do an article yourself if you're that good. Darren is good enough to research, compile and share these articles - for free - which takes up his valuable time, he does this to help us 'amateurs' better our game, we should all be grateful for his selflessness. Thank you Darren, looking forward to the other installments in the fascinating world of photography!

  • bob sagget September 13, 2011 05:01 am

    Hi Darren – I’ve always used the water/hose analogy with my students, but the ISO isn’t the water pressure – it’s the container you’re filling. EG a low ISO is a tub, and a high ISO is a teacup. I would tell my students that each frame was a container that needed a certain amount of light (water) to fill it and give the ‘correct’ exposure. The aperture is how far you turn the tap on, the shutter speed is how long it’s on for, and the water pressure equates to the intensity of the light on that particular day (sunny day at midday equals a high water pressure whereas foggy morning, early in winter equals a very low water pressure).

    Read more: https://digital-photography-school.com/learning-exposure-in-digital-photography#ixzz1XlZlLBiu

  • jo newton August 29, 2011 03:43 pm

    Hi Darren - I've always used the water/hose analogy with my students, but the ISO isn't the water pressure - it's the container you're filling. EG a low ISO is a tub, and a high ISO is a teacup. I would tell my students that each frame was a container that needed a certain amount of light (water) to fill it and give the 'correct' exposure. The aperture is how far you turn the tap on, the shutter speed is how long it's on for, and the water pressure equates to the intensity of the light on that particular day (sunny day at midday equals a high water pressure whereas foggy morning, early in winter equals a very low water pressure).

  • P.Simon August 22, 2011 02:30 pm

    I do like the window metaphor.But what Marilyn says makes sense-provide the fundamentals of how the camera works,then you should have the DESIRE TO LEARN

  • Marilyn Armstrong August 20, 2011 03:37 pm

    I am the typo queen.

  • Marilyn Armstrong August 20, 2011 03:36 pm

    The metaphor thing doesn't work for me. I would rather explains the fundamentals of how a camera works. Maybe it's all the decades of technical writing. Plus the years of teaching technical writing. But the threeste basics that control the use and collection of light so that they can combine into an image. If I use any analogy, it's that I still think of ISO as film speed. My age is showing.

    When I was starting out, a friend taught me the basics by taking an old brownie camera apart and showing me the pieces, what they did and how they worked. After that, the rest was trying out combinations and seeing what worked.

    Although many things have changed -- there are gazillions of ways to tweak all the permutations of each element of photography -- the basics are the same. Ultimately you need to understand those basics or you'll never get the rest. Whether or not you've got "an eye" is talent. God dispenses that. The rest is information and mechanics. Everyone can understand it if given clear information ... and the really critical element, a desire to learn.

  • mlaksv August 3, 2011 01:36 am

    Very good explanation!. Gave a picture easy to understand and can relate with. Till now I read many blogs and articles and got confused with all the technical jargon.

  • Ashley July 1, 2011 04:37 am

    I like the window metaphor. It makes total sense and I can wrap my head around the terms.

  • Kapil Paliwal June 8, 2011 01:18 am

    Analogies are always irritating! An excellent graphic in itself is the triangle which explains best.

  • Carlos Orozco June 8, 2011 12:43 am

    The window example did the trick.
    However, when it's time to take the shot, I always get confused about what to do first; do I take off my glasses, or call for a carpenter to build me a bigger window, or keep the windows open for longer periods of time? By the time I do one of the three, I've already missed my shot!

  • eu June 4, 2011 05:35 pm

    hmm, I just can`t seem to diffrentiate ISO and aperture but The Window Metaphor helped me somehow, how do i understand these two elements? :) should I read also the manual of my camera?

  • Virginia May 26, 2011 05:48 am

    I am so glad that I found your site. I bought a Panasonic LX5 and have wanting to relearn the basics and go on to all the things i can do with my new camera. I will also recommend this site to the beginners I'm hanging around right now.

  • ivesliou May 19, 2011 02:24 am

    Thank you so much! This is a great tips and might be useful for creating nice photography..

  • Deen May 12, 2011 01:17 am

    Thank you Darren, this is a very informative and kinda able to understand article. Cheers, Deen

  • nancy2jj April 24, 2011 04:28 am

    Big thanks to Darren. As a newcomer to photography, I very much appreciate the tips posted on the website... :)

  • Gokkasten April 21, 2011 01:16 am

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  • genevieve April 17, 2011 10:28 am

    i've always taken pictures in my head, could see them apart, and of their own, now im trying to make those scenes appear with my camera, a mental picture i can materialize in the physical realm scenes from my mind's eye-i'm hoping this sinks in... asap, now that im becoming aware of the goldmine that my camera really is

  • Zubairu April 14, 2011 03:46 am

    Thankyou so much i bought a Nex-5DB last week and started checking this website everyday to learn new stuff!

  • Luciano Alexandre March 30, 2011 07:31 am

    I loved the analogy of the window! I'm a beginner and I'm learning just as a hobby because I am fascinated by the art of photography. Thank you Darren!

  • Nickie March 22, 2011 11:10 am

    I am so confused. I have taken lots of pictures by using just my eyes and not paying attention to the ISO settings etc. Please help. [

  • fajar February 26, 2011 07:21 am

    very nice article

  • raf February 2, 2011 09:31 am

    Thanks so much for the brilliant Window Analogy! made things so much easier to understand.

  • f-stop January 27, 2011 03:24 am

    Regarding the filter analogy. Though you're right about the fact that a filter can effect the exposure numbers, that does'nt factor into the basic exposure triangle theory because you are talking about an accessory as opposed to the basic camera and how it calculates exposure as well as how you interpolate that information. There are several add ons that will effect exposure. Extension tubes and bellows for example. I understand that these all ultimately effect the final exposure, but they are not part of the basic exposure calculation that is done for every photograph taken whether these type of variable enter into the equation or not.

  • Karen January 23, 2011 07:20 am

    Loved the window example!

  • Lisa Irish January 18, 2011 01:58 am

    I love the window metaphor. I just don't get a lot of this stuff, and this is the one time I GOT IT Thanks so much

  • Silvia January 13, 2011 03:25 am

    i have a question
    what settings should i put my camera if i am taking pictures of someone at a club dj ing
    i have a canon rebel 500D T1i

    i find it so hard to captue great images

  • Jenny December 29, 2010 05:29 am

    The Jeromy Jacobs cheat sheet was just what I needed. I understand aperture, iso and shutter speed but not so much how they interact with each other. It's a great little tool which I've printed off and will laminate just like he did. Also it is useful for the old SLR photographer, because then one never went to an iso of say 3200 and I always got large and small aperture mixed up but it's all there.

  • Russell December 4, 2010 03:19 pm

    great post. Really explains the initial and basic components of photography well. Very informative.

  • Roderick De Mesa November 28, 2010 12:57 am

    Still need a lot of reading to do and practice... just new to this hobby, hope i will like it all the way......
    thanks for the help.....

  • Amit R November 21, 2010 02:53 am

    The window metaphor is superb !

  • Kelley Zane November 10, 2010 01:31 am

    I newish to photograpy but this website has helped a lot in the process of starting my career.

  • Shabbir Rozi November 2, 2010 09:36 pm

    As a beginner of digital photography. for the 1st time I understood about Exposure ,( ISO, aperture, and shutter speed. thanks for DPS.

  • scottyv October 29, 2010 03:30 pm

    This is a great article! Sometimes when I'm out in the field, I tend to overthink things and get confused. I used these metaphores to get over that. Thanks for the great tips DPS!

  • Miss Britt October 21, 2010 10:21 pm

    I read the garden hose metaphor recently and that was the one that FINALLY stuck with me and helped me to remember whether or not I want my FStop to be big or small to achieve a certain effect.

  • Trimm October 13, 2010 07:39 am

    Great analogy, i was about to give up and only use manual!!!!!! Thank you so very much.

  • Leslie-Ann October 11, 2010 10:23 pm

    I love this website! I teach young students (middle school) about photography. This metaphor really helps them understand what aperture, shutter speed, and ISO are and how they relate. Thank you!`

  • JJ Konstantin October 10, 2010 04:27 pm

    The window analogy was very helpful. I still need to play around with the settings and this will definitely help me!

  • Kevlar September 18, 2010 08:16 am

    Thanks!! Great article!
    Really helped me understand what exposure means..

    Another way to experiment what exposure is, is to set the mode to "auto" then see what settings it gives you.. compare this to the manual settings that you would have chosen..

  • SUILCHA September 14, 2010 07:38 pm

    that window example was quite good to understand pals

  • netflicks trial September 14, 2010 06:37 am

    I found your tutorial on “exposure” for beginners very interesting and very informative. It was easy to understand and relate to.

  • anonimum September 6, 2010 02:33 am

    The example of the window was very helpful for me and inspired me to take a really beautiful picture

  • anonimam September 6, 2010 02:30 am

    The person who thought the example of the window, was very intelligent, it was the most helpful for me

  • Tina Harris September 3, 2010 04:37 pm

    I have been trying to master the art of product photography for a while now an have issues with taking pictures of engraved items made from silver. I have found this task particularly difficult. I have been using a light box for a while with limited results but have read parts of Bryan Petersons book which has really helped since. I have now taken some good photos for a personalised gifts website Keep It Personal Gifts and have more work off the back of it.

    Very good article.

  • Food Lover September 1, 2010 06:22 am

    You know in my cam I have a special mode to change them myself and I've never thought about it, thanks so much for the info.

  • Lyn Drathring August 23, 2010 02:35 am

    I have heard the window metaphor before, however 'seeing' the metaphor with the shuttered window example makes it come together much better for me. Thank you for the great article. Lyn

  • Anoop August 12, 2010 04:32 pm

    Bought a Nikon D90 recently and experimenting with it. I am new to photography so this article is quite helpful though the metaphors are quite confusing on first read.

  • ace August 6, 2010 08:45 am

    hello darren rowse!
    you're my angel...thanks for this work you are doing...i hope to get better pictures now that i have read something that gave me more knowledge...it gives us beginners more encouragement to try it...photography lesson is expensive here, it's good i found your site before i begin any picture taking...God bless you on the work you do...God speed...have a blessed evening/morning...

  • Ed Normile August 5, 2010 02:39 am

    Darren, I feel I can address you this way as I have come to feel an almost familial relationship now that I have haunted this site so long, I must admit analogies tend to confuse me. Using the window analogy, using windex on the window would be the same as cleaning the sensor, or would that be like opening the aperture? Just joking this was, as usual, a very enlightening article. Keep up the good work.


  • Lova August 5, 2010 12:02 am

    Nice article, normally if i shoot under the sun i always use flash to light my subject.

  • Chuck Nardo August 3, 2010 12:14 am


    Would like to know if you can reformat your tips with a "Printer Friendly" option so we can downlaod text and images only without all of the stuff around it and whatever IE decides we need to see also.

  • Arie Gez July 29, 2010 05:07 pm

    Hi Darren.
    I would like to thank you about your simply explanation to subjects off the ISO, Aperture and Shutter Speed.
    now I know more about this three...
    I would like to leren more about to use camera with flash (ext. flash). If you can send me by Email some subject matter I would thank you.


  • Treeface July 21, 2010 02:43 pm

    I love this website. I know the fundamentals of exposure quite well, but was not pratically impressed with these metaphors lol. Strike one for an otherwise grand slamming website

  • cheap louis vuitton handbags July 18, 2010 09:00 pm

    I found your tutorial on “exposure” for beginners very interesting and very informative. It was easy to understand and relate to.

    Thank you and I look forward to more tutorials from this site.

    Read more: https://digital-photography-school.com/learning-exposure-in-digital-photography#ixzz0u1xtGw11

  • Hutch July 13, 2010 11:15 am

    I like the window example but instead of glasses. Use window tint. Change the tint value (iso) more or less light can be sensed inside the room.

  • Kevin July 6, 2010 12:25 am

    The exposure triangle illustrates the camera's three internal mechanisms of controlling exposure. Considering other 'fourth' factors, such as light or filters, is a separate topic.
    i agree with several posters that an analogy should be used to clarify a concept, the ones used here are so-so.

  • Ricardo Faria Paulino July 2, 2010 12:13 am

    One good analogy to explain ISO is to compare the ISO to the Volume in a Hifi system.The only difference being that ISO is related to eyesight and Volume to earing. If you crank up the volume in a stereo system you'll be able to hear better if taken too high you will start getting distortion. The same with the ISO the higher you put it you'll be able to see better but if taken too high you'll get noise. This analogy only serves to explain what ISO is and how it works.

    Hope it helps



    [eimg url='http://www.ricardofariapaulino.com/storage/36936_405593727991_539162991_4510820_969298_n.jpg' title='36936_405593727991_539162991_4510820_969298_n.jpg'][eimg url='http://www.ricardofariapaulino.com/storage/36936_405593727991_539162991_4510820_969298_n.jpg' title='36936_405593727991_539162991_4510820_969298_n.jpg']

  • Ricardo Faria Paulino July 2, 2010 12:11 am

    One good analogy to explain ISO is to compare the ISO to the Volume in a Hifi system.The only difference being that ISO is related to eyesight and Volume to earing. If you crank up the volume in a stereo system you'll be able to hear better if taken too high you will start getting distortion. The same with the ISO the higher you put it you'll be able to see better but if taken too high you'll get noise. This analogy only serves to explain what ISO is and how it works.

    Hope it helps



    [eimg url='http://www.ricardofariapaulino.com/storage/36936_405593727991_539162991_4510820_969298_n.jpg' title='36936_405593727991_539162991_4510820_969298_n.jpg']

  • Trish June 30, 2010 07:16 am

    Oh I just so struggle with all this, thank you for the window shutter explanation my brain is finally letting something in. Thankyou Trish

  • sam June 27, 2010 09:12 am

    I am very very much new to this , I just got a gift(Nikon D90) from my wife. I want to learn as much as I can thru forums and some readings and reviews. some terminologies are very foreign to me. I hope somebody can walk me thru this. Thank God for this site that it has a page for brginners.

  • monica June 25, 2010 09:24 am

    The metaphor was beyond helpful! Thanks!

  • Sajith June 24, 2010 05:34 pm

    Great Article...Thanks alot Darren!...

  • Robin June 23, 2010 04:16 am

    Thanks so much for this article. Your analogies truly help to give me an understanding of the three elements and how they work together.

  • Rhalmi Mohammed June 21, 2010 10:08 am

    Great article! I've never known about those three elements of expousre. Thank you!!!

  • turtlena May 21, 2010 12:56 pm

    I think with the window metaphor the ISO is more like the screen you would have on a window which controls all the light coming through the window, and the sunglasses would be more like a filter (which someone also mentioned below)

  • fer May 18, 2010 03:19 pm

    excellent !!!

  • Michael May 18, 2010 02:06 am

    "Ok – it’s not the perfect illustration – but you get the idea."

    Why use any metaphor that is not 100 appropriate and helps to clarify the points being made? If you're going to do that, then why not just put the time into writing simple, super clear language to explain what's going on? The reader can then fill in the cracks with their own metaphor.

    I found all these less than perfect metaphors add more noise to what's already a confusing topic,. They were a lazy way around the best approach which is to explain and show what you're trying to communicate in clear and simple terms (I know that's not easy, but isn't that really what you're trying to do?).

  • Cath May 17, 2010 10:57 pm

    It's always good to read another way of thinking about this relationship - everyone conceptualizes these things differently, so it's good to have lots of ways of describing it.

    I photograph a lot of indoor ferrets and underwater spearfishing - i.e. action shots in low light, so I am constantly battling ISO speed vs. shutter speed.
    Here's a rare shot where I was able to capture my ferret in natural light with a relatively low ISO (200), and hand held:
    exposure time: 1/5 sec.
    focal length 55mm (Canon Rebel XSi, kit lens)[eimg url='http://ferretexpert.info/wp-content/uploads/2010/01/ferret-paper-bin.jpg' title='ferret-paper-bin.jpg']

  • Christine May 14, 2010 07:13 pm

    I am sooooo grateful for this site!! It is amazing how easy it is to understand it all when things are explained the way they are here! The penny just drops!!! Thank you.

  • Alex Suarez May 10, 2010 01:56 am

    @bob bevan smith: We think very much alike. I've made much the same analogy at http://alexarsuez.com/exposure except that I equate the ISO to the size of the container, rather than the water pressure. Like a container, the ISO determines the quantity of light needed to get a proper exposure. If you think of filling a container with water (Light) to be a correct exposure, then changing the size of the container would be the equivalent of changing the ISO. A shot glass would be a high ISO because it takes very little water (light) to fill it up. By comparison, a swimming pool would be a low ISO.

    To take this even further, I would liken the water pressure to the brightness or intensity of the light, not the ISO. The brighter the light you have, the faster the shutter speed or smaller an aperture you can use, but your ISO is still your ISO. It still requires the same absolute QUANTITY of light to hit the film/sensor to get that proper exposure.

  • jack May 8, 2010 01:02 pm

    In may not be needed to use a high ISO to shoot action/sports. It would depend on the amount of light available and what you want to do. If you want stop action then you would need a fast shutter speed versus blurring the action where you need a slower shutter speed. On a bright day you might be able to shoot NASCAR with an ISO of 200 and fstop of 8 and shutter 1/500 say, Again depends on the light.

  • Bob Bevan Smith May 5, 2010 06:20 pm

    I think the garden hose example best describes the relationship of the three. Instead of the width of the pipe think of how wide open the tap is. A tap only slightly turned (tiny aperture eg f16) lets through a dribble of water but a fully open tap (wide aperture eg f2.8) lets through lots of water. A high water pressure (high ISO eg 800) gets more water through the same tap opening in the same time. The time the tap is open (exposure time) limits the amount of water coming through - longer opening (low speed) = longer exposure and hence more water.
    So to fill a watering can exactly to the top without overflowing, you can let the tap dribble for a long time at low pressure, or open the tap fully, or increase the water pressure, to reduce the time. If the pressure is too low, or the tap not open wide enough, or turned off too soon, the can is not full (under exposure). If the pressure is too high, or the tap too wide open, or left open too long, the can overflows (over exposure).
    To understand the effect of ISO, think of trying to fill a can from a high pressure hose - it takes a very quick hand on the tap to get it exactly right. So a high ISO is really good for photographing fast movement like sports, and a low ISO gives better results with static objects and in general gives better control = better quality.
    Hope that helps!
    PS. ISO stands for International Standards Organisation, and all modern cameras use that standard, so any two cameras on the same settings will give the same exposure within limits.

  • rosy m May 3, 2010 09:50 am

    Hi Darren R,

    I found your tutorial on "exposure" for beginners very interesting and very informative. It was easy to understand and relate to.

    Thank you and I look forward to more tutorials from this site.


  • darren_c May 2, 2010 10:45 am

    Understanding Exposure, by Bryan Peterson, should be required reading for all beginning photographers. This was one of the first books that I picked up; mainly because it was a simply written instructional manual with lots of colourful and well composed examples.

    Besides, who wouldn't be inspired by Bryan's photography?



  • abdullateef April 30, 2010 10:00 pm

    i was discussing with fellow photographer abt what i read from ur site and what he told me was dt if i really know all this things, then i must be a great photograper. u knw, i come from an area where in every 100 photographer, there is hardly one professional. tx a million.

  • Marisa April 28, 2010 06:58 pm

    Love the window analogy! Makes so much sense.

  • Ramil April 24, 2010 10:16 pm

    Isn't photography like cooking? You got to have proper utensils and stuff to produce perfectly cooked food. so what about the metaphor of this: shutter speed is the length of time you expose your food to heat; aperture is the size of the burner or heating element (the bigger the easier to cook): and ISO the pan's thickness! And think of this,isn't the lens like pots and pans? you can cook on just about anything but it would be difficult using improper one. And the ingredients should be right to make it taste good!
    Just like the elements in the picture,some should be there and some shouldn't be.

  • saya_sayan April 21, 2010 12:51 am

    This site is a life saver, thanx Darren. I've had my canon 40D for quite a while, but never really had any time to sit down and pick at it.
    All i've known, is that i cannot stand to use Auto. I always liked using manual, but never really understood it. I knew how i wanted my picture to come out, but never got it right, and this would discourage me greatly.
    But now thanx to you, i understand the relation between those 3 settings that always gave me a headache.
    Now i just gotta practice, and hopefully, in due time, my pictures will come out as i see them....

  • Utpal April 17, 2010 12:07 pm

    I read all the comments again and again in my leisure. In response to Cole Sun's comment on 27th jan, I would like to tell that setting of ISO depend on the lighting condition. Brighter light - lower ISO and Low light - higher ISO. But one thing always should be noted that higher ISO increases the digital noise in the photo. You can compare this by taking a landscape photograph with minimum as well as with maximum ISO setting at the same time. You will find by enlarging the lower ISO results a smooth photograph and the higher ISO results some noise in it. So, only in extreme low light condition and for night photography, higher ISO should be exercised. I personally, always try to take photograph with emphasizing Aperture control by setting ISO setting to the minimum.


  • DR KIRAN DESAI April 16, 2010 08:17 pm

    Excellent tutorials. Lots f good carry home messages. Please forward all tutorials. i want to learn more from u.
    Very palatable way of explaning
    Dr. kiran

  • Paul April 15, 2010 02:01 am

    Here's a pretty detailed review on aperture that I wrote a short while ago:


  • Adam Le Good April 11, 2010 04:24 pm

    I found the window analogy useful, but would substitute sunglasses for curtain thickness.

  • Carol April 9, 2010 11:08 am

    The window metaphor is so helpful.. Ive been reading the difference between the exposure triangle in every site or book and this one really helped me understood so well. Thank you!

  • IanRay Cruz March 24, 2010 07:53 am

    Thank you for sharing to us this information about photography. I'm a newbie and got my Canon 500D with 18-55mm kit lens just 8 days ago, a friend told me about your site. This is like going to school of photography for freeee! ^____^
    i love to read your guide. They are easy to understand and you got a super duper cool illustrations! lol! But i have to read again and again so i could share it to others too, specially to those who don't have internet at home.
    again big thanks to you


  • Brittani Gonzalez March 19, 2010 08:07 am

    Thanks for the analogies because it definitely made it easier to understand the connection between the three. The window analogy was the easier to understand. Hopefully I can graduate from automatic mode soon. Thank you


  • kavi March 17, 2010 02:47 pm

    Thanks for your illustration expecting more in the future

  • enrolled agent exam March 12, 2010 05:42 am

    Thank you for the information. I am so excited that I've found this sit. I've learned so much in such a short amount of time.

  • peony4me March 12, 2010 03:58 am

    Mr. Darren, those are great metaphors and really help visualize these 3 main things in photography. I am also beginner plus photographer and your explanation helped me a lot.
    The only thing left is practice, practice and practice.
    I am trying to do your assignments and hope will show some progress soon.
    I also wanted to add that your site is awesome! just awesome.

    thank you very much!

  • Christina March 12, 2010 03:37 am

    The window analogy is probably the easiest to understand, but the sunbathing example goes a little farther in explaining how the components are interrelated. Great simple explanation - thanks!

  • vineet March 9, 2010 12:24 pm

    i am a beginner and this is the first time i could read the interconnectedness of 3 aspects and more than that it seems there is no 4th one..thanks

  • utpal March 5, 2010 09:03 am

    Camera is your eye. compare it to your eye. you will get every solution.

  • gail March 5, 2010 03:36 am

    Thank you so much for the simple, clear way of explaining.
    I've been reading and reading but the way you just said how the exposure triangle works I got it. Thank you Thank you.

  • ebenj March 5, 2010 03:19 am

    WOW, AWSOME , AN EYE-OPENER for a beginner like me. Thank you very much Mr. Darren Rowse for a very enlightening & informative article regarding "The Exposure Triangle". At this moment, as a newly- registered member of DPS, I prefer to stick with the basics of using my naked eye vision in applying the Exposure Triangle. You may not believe it, I have with me Nikon F55 SLR, Sony Digital Handycam Digital 8, Sony Cybershot DSC-S700 and Nikon D5000 SLR Digital Camera. I never bothered using the "Manual Mode", instead all of my shots were done in "Auto Mode". With the help and guidance from your amazing site coupled with constant but directed shooting practices, I can shoot with confidence quality and amazing pictures.

  • Jenny March 4, 2010 09:52 pm

    Having been given a Canon EOS 7D as a present, I just spent two days on a basic photography course. If I had found this site first, I would have saved an awful lot of money, the site is awesome and in an hour reading about the Exposure Triangle I feel I've learned more than two whole days spent with a tutor, excellent though she was. I've bookmarked the site and I'll be back - again and again and again

  • Kent Judkins March 2, 2010 08:27 am

    From what I understand, ISO settings do not change the sensitivity of the sensor but rather change the amount of amplification of the data between the sensor and writing the file to memory. The audio equivalent would be like turning up the amplifier as opposed to making a microphone more sensitive.

  • Dougory February 28, 2010 04:01 am

    Years ago, my dad had a Kodak Speed Graphic and I learned basic photography from him. His main tool was a light meter that was almost mandatory. Am I coming full circle if I wander from Full Auto???

  • Adrian February 21, 2010 02:55 pm

    For me the best explanation is the window. Thank your very much for this wonderful guide.

  • Wong Zong Yan February 21, 2010 12:14 am

    Great for beginners!

    Thinking of getting a DSLR. This website is a great help! :)

  • sourabh February 19, 2010 06:17 am

    hye thnks this is very good way understand the basic principal of photography

  • jiggerjohndelgado February 15, 2010 07:45 pm

    i like the site too!

  • Aishwarya February 10, 2010 08:43 am

    Found the window analogy really really helpful. Thanks so much! I'm taking a photography course now and this website is proving to be really helpful. Thanks again.

  • O'Fallon IL Photographer February 6, 2010 01:29 am

    Good explanation of what is going on with your camera settings. I think what would be icing on the cake is if someone were to make a web application that let you experiment with changing ISO, shutter, and aperture. It would give beginners a better idea of what changing each setting actually did to the resulting image. I may end up writing an application myself and putting it on a new website we're going to be creating for teaching photography principles.

  • gilbert February 2, 2010 07:36 am

    i have just bought my DSLR cam yesterday.,.. and I dont know whats the meaning or use of ISO, Aperture, Shutter... now i was enlightened after reading this one!!!

    now im learning!!!

    thanks a lot!!!

  • Jessica January 27, 2010 04:31 am

    Yes I definetly found the window analogy most helpful as well! However another way I look at it is that the APERATURE is like the pupil of your eye dialating to let in more or less light. THe shutter speed is like your eye blinking- so how quick is it gonna catch motion and the ISO would be the sensitivity of your eye to light- do you need to squint because its too bright etc... would this be correct?

  • Cole Sun January 27, 2010 03:17 am

    can anyone explain to me why i would need to adjust the ISO on my camera?

  • ja ruler January 27, 2010 03:13 am

    i thought this site was unbelievalbe! so many good tips!!!!

  • Luke Surma January 27, 2010 03:13 am

    i love the site!!!!!!!!!!!!!!!!!!!!!!!!

  • Ely Dennis January 26, 2010 06:49 am

    For rina minca.

    I think the best explanation would be from Bryan Peterson's book. "understanding exposure". On page 20 of that book he explains in a very simple way to understand ISO and its use. ISO is used in combination with aperture and shutterspeed. It does not work on it's own. Again, if you can get your hands on this book it will give you a very clear meaning of ISO. Hope I helped you a little bit.

  • Rina Minca January 26, 2010 06:07 am

    I found the window metaphor the vest, but I still don't get ISO by itself. Anyone able to explain? I understand aperture and shutterspeed really well, and how the three (plus light) relate to each other, but not ISO by itself.

  • Ely Dennis January 26, 2010 04:05 am

    Very good article. It is always constant practice and shooting everyday really helps the process. Learning new combinations of determing the correct exposure. Once one learns the rules of these elements it is then that one can turn on the creativity. I also purchased Bryan Peterson's "Understanding Exoposure". It is a book every photographer should have in their library or backpack.
    Thanks again for this great information.
    Best Regards,
    Ely Dennis

  • Stacey Malleck January 26, 2010 03:49 am

    I found this article very helpful. Thanks! The window analogy makes the most sense to me.

  • Water damage Roseville January 22, 2010 08:57 am

    Thank you very much. I've owned a digital SLR for a while now and never really understood ISO and aperture, but your detailed explanation, and clear demonstration makes it easy for me to understand both.
    I can’t wait to try and experiment shots with different settings.

  • Amul Kapoor January 20, 2010 05:11 pm

    Had joined these classes on Photography about two months back. The lessons are very interesting and good. A layman like me has learnt a lot. Recently bought a Nikon P 90 DSLR camera and would love to master the same through these lessons.
    Thank you,
    Amul Kapoor

  • Sola Bamgboye January 18, 2010 04:25 am

    Nice Metaphors. - Think the window one best explains it best of the three..

  • Poje Mario January 16, 2010 06:47 pm

    Nice metaphores, I will sure use them for explaining ;)

  • soumya January 16, 2010 08:32 am

    I found this tutorial very helpful. Thanks

  • Stagg Student January 16, 2010 02:12 am

    The window metaphor was extremely helpful. We are currently learning about camera settings, so it was a nice visual aid.

  • Asheesh January 16, 2010 02:04 am

    The window example was the best. Thanks!

  • Karen Stuebing January 14, 2010 12:09 am

    Very informative in an easy to understand way. Another trick is to meter the scene by pointing your camera at the brightest and darkest part and adjusting aperture, shutter speed or EV compensation according to the what the camera tells you about each area. Whether or not it's over or under exposed too much This only works if you have time as in a scenic.

    And sometimes you actually want dark areas as in a silhouette sunset photo. I don't think you ever want blown high lights except maybe in a black and white photo.

  • joy January 8, 2010 08:30 pm

    i've learned the basics..
    it tooks a lot of effort to understand the basics when your still an amature..
    it helped me with this one..tnx

  • utpal January 4, 2010 01:33 pm

    One unanswered question always haunts me that are the elements of triangle i.e. ISO, aperture and shutter speed universal for all brands of camera ? I use three cameras of Canon, Nikon and Sony; but experienced different results in framing shots with same value. What;s the reason !

  • WATTS January 3, 2010 08:06 pm

    Thanks for a very infomative post, pls keep them coming, All the best in 2010,

  • Jonathan January 2, 2010 06:00 am

    Love this article and the related technical basics. I have included links to them in my new blog as a good place to start learning about digital photography.


    Keep up the excellent articles, I am always learning from them.
    (and I am new to the blog circuit, so if I have violated any rights, please inform me and I shall remove them accordingly.)

  • utpal December 31, 2009 01:12 am

    In my experience of photography, i feel higher ISO always damage the quality of photograph. If you want a quality photograph, you should always work with minimum ISO and give emphasis on aperture / shutter control . Only in extreme low light condition, after exercising aperture and shutter speed to their optimum level; a photographer should exercise the higher ISO.

  • Gbenga Loveeyes Images December 30, 2009 08:04 pm

    This is a nice analogy but I think the triangle should the other way. It should stand on the iso point that is after you have done aperture and shutter speed then the iso can be considered. Thanks for all your insight. Merry Xmas and a prosperous New Year.

  • utpal December 27, 2009 10:01 am

    Aperture and depth of field are very much related. Aperture only the aperture controls the depth of field. But how? Aperture allows you to control the openings of the lens mouth. The more you open(high aperture, say 2.7) the lesser depth of field and more you close the lenses mouth, the depth of field increases gradually(low aperture, say 8.00). Now the point is; why depth of field control is needed. While taking a landscape or any other photograph along with a close up subject(suppose, you want to shoot a landscape from a hiding of tree leaves and you want to keep the both tree leaves and the landscape prominent in your photo) , you need to fix your aperture value to 6.00, 7.00 or 8.00. Otherwise one of the subject you select to shoot becomes blurry.The work of aperture could be described with an example. Take a piece of paper, make a big whole in the paper and look through it with somebody in front of you. You will find either the person or the landscape will be prominent in your looking i.e one subject will definitely gets blurry. But if you make a whole of smallest size in the paper and look through it, you will find both the subjects prominent in your looking(i.e. depth of field increases with the reduction of hole size in the paper).

  • adith December 27, 2009 12:30 am

    hey darren!!!
    the window was a good metaphor.....but is it possible for u to explain , how aperture an depth of field r related? couldnt figure out d logic behind it ......:-(

  • Henn December 26, 2009 02:24 pm

    Thanks a lot, after reading your articles it's really give me the answer that most of the time i'll wondering myself when capturing. Thank you very much.

  • utpal December 25, 2009 02:58 pm

    As a photographer one thing always haunts me, why the higher ISO makes a photograph more noisy? Aperture control allows you more or less light; shutter speed controls the static or moving objects photography. But how the photograph becomes noisy with the increase of ISO ? I've damaged many photographs in low light with higher ISO.

  • Saz December 24, 2009 02:41 pm

    Thank you very much for the window illustrative. It really something for me. You are the man. Thank you.

  • redbaron December 22, 2009 04:11 am

    thank you very much for making it so easy for me to understand how exposure work. Are there any right combinations that you would recommend. Thank.

  • Blue Boeser December 18, 2009 05:51 pm

    Thanks Bryan for your amusing explanation of how exposure works.
    By the way, try to eat more carrots, they tan your skin from within and |
    you won't get a sun burn so quickly (vitamin A)! No kidding!
    I'll have your pyramid in mind, it's a good help.
    Season greetings and a Happy New Year
    Blue Boeser

  • Jason Hopkins December 18, 2009 03:37 am


    I can never get my head around ISO - it is always set on 100!

  • Ashish December 11, 2009 05:24 pm

    Hi Darren,
    This is an excellent & resourceful website. Thank you for sharing the knowledge, it is a very generous service. I am new to photography and your articles really make it interesting and fun. I am defi subscribed! :)


  • Ajith Kumar KC December 7, 2009 10:00 pm


    I thoroughly enjoyed reading and understanding the triangle of exposure. I read through some of the comments too. I felt an urge to raise a few queries.

    Given that all other conditions are the same, varying one value, say ISO setting would change the values of others. For a very dark night photo or a high action sequence of fairly well lit Xmas tree, we may choose a higher ISO value, say 800. This would bring changes to the shutter speed (higher) allowing us some degree of hand shake. If we need to cover a large foreground and background in the focus, we may have to choose smaller aperture also, thus sacrficing on the shutter speed. Each f stop reduction would mean halving the amount of light trasmitted through the lens.

    Is my understanding correct?

    Do the ISO rating change from film camera to digital since the process od recording and the media are totally different?


  • Chris December 2, 2009 06:29 pm

    I think this is a great site, and a nice tutorial on exposure. I do agree, however, there is a 4th element: LIGHT!
    To limit the conversation to three (triangle) issues is to miss THE most important factor, light.

    The light available.
    The light we may choose to bring.
    The strategies we may use to reduce the light.

    Critical, in my opinion!

  • hari November 27, 2009 12:17 am

    wonderful lessons for a beginner like me

  • Franco Campese November 24, 2009 03:58 am

    Really great analogies. Never thought about photography like that

  • wedding November 20, 2009 03:42 am

    Great post. You've both increased my respect for professional photographers and made me want to pick up my old camera and explore these concepts.

  • Tiffany November 19, 2009 08:50 pm

    ISO?? it says the ISO changes to grainiess..so does that mean the more ISO you have the less grained it will be?/ that is the only thing i dont get!!

  • NAVEED ASLAM KHAN November 18, 2009 07:49 pm

    Thank you mr. Darren very nice article about exposure triangle. It is very use full for beginner. Being a beginner
    i am going through all the tips you give and also i try out them.

  • S.Chandrashekar October 16, 2009 06:05 pm

    Can you please expand ISO ie what does these letter stands for?

  • S.Chandrashekar October 16, 2009 04:55 pm

    Thank you Mr.Darren very usefull tips for ammetures like us illustrations with windos gives fair idea about shutter, apperture and iso. Being a begine i am going through all the tips you give and try out them.

  • Jan Ole Peek October 16, 2009 04:31 am

    Very nice article, including the 3 individual articles about ISO, shutter speed, and aperture. I truly have a better understanding of this now, both how they work individually and how they impact each other. Thanks!

  • georgia October 7, 2009 11:50 am

    Hello Darren! I've been reading a lot of your tutorials and i'm very grateful. I find the window analogy very easy to understand the relationship between the shutter speed, ISO and aperture. thanks a lot. More power to you and God bless...

  • Laura Laws September 23, 2009 05:46 am

    Wonderful article. Thank you!

  • photomesum September 19, 2009 04:59 am

    wats crakin just dropin sum fly commentz through here haha... ps like the ISO triangle.. l8r pan.

  • keith September 15, 2009 07:04 pm

    Back in the old days of film I used to under expose and increase the developer time. Is there a way of getting a slower ISO with digital other than 100? eg. 64,50 or 25.

  • Maisha September 14, 2009 07:15 am

    The window metaphor was helpful :-) thanks!

  • Phillip September 13, 2009 06:07 pm

    Great Metaphors on understanding 'Exposure' Darren. First let me say this is a wonderful site and I have learned and been challenged to try new techniques.
    Probably not saying something that has not already been said - but I think the one thing about Exposure is 'How you want the final photo to look'. All the three things elements - ISO, Aperture and Shutter Speed are all linked to each other - change one and you must change at least one of the other elements has to change to get the same 'Exposure'.
    To me the ISO is the Anchor or main variable and that the other two are tied to it as the Main Controlled and they are proportionally changed to yield the perfect exposure.
    I guess mine goes back to the film days when you had to know what lighting conditions you would have and if it was going to cover the different effects you might be going for. The films ISO is set, and only one combination of Aperture and Shutter Speed will give you the correct exposure. That correct exposure for a given ISO is the 'Amount' of light that falls on the film or 'Digital Sensor' and there is only one state that is correct for a given ISO. Like Electron explained about the water flow and a glass - you are shooting for a full cup of water (correct exposure) and it can be achieved quickly with fast flow (Wide Aperture and fast Shutter) or Slowly (Small Aperture and long Shutter) - they both fill the glass (or achieve correct exposure) but in different ways.

    Phillip - VietVet'67 http://www.flickr.com/photos/vietvet67/

  • fish September 8, 2009 08:57 am

    i have question,. can help anyone,. if you do moving subject or for example sports like skatebording or basketball,. what should be the setting mode,. like manual or its ok! program mode? bec. my problem in manual the subject is become blured. tnxs!!!

  • lazar liebenberg September 1, 2009 12:17 am

    thanks, im just starting photography and love it. this really helped me

  • Eileen August 27, 2009 09:55 pm

    Thank you so much! Finally you've explained these concepts in terms I can grasp. Metaphors are great and these are quite memorable. Now I'm going to follow the link and read more about ISO.

  • Alex August 26, 2009 06:36 am

    As a newcomer to digital photography, I've been struggling to get my head around the jargon and the relationship between the points in the triangle and how changing one aspect affects the others. This article and further discussions and suggestions by readers helps a lot. I wish to suggest www.play.com as an alternative to amazon for books. I live in France and get postage included in very competitive price.

  • Kerry Garrison August 21, 2009 09:54 pm

    I think the concept of the triangle is correct (see my original article on this at http://cameradojo.com/2009/01/28/understanding-exposure-with-the-exposure-triangle/ since the these are the camera settings that affect exposure. Light is an external thing that is not in itself controlled by the camera. Even though you can dim/bright/move light, you still have to get the camera settings correct for a good exposure.

  • Jennifer Moore August 21, 2009 03:16 am

    This was great! The window analogy, I thought, was perfect. It really clued me in to a lot of things I was missing.

    @Jeremy-Thanks for the cheat sheet.

    I have not been at all afraid to use manual mode, but I have defaulted mostly to shutter priority or aperture priority, because they have been the easiest to understand. I don't know why ISO is so difficult for me, but I won't stop experimenting, and I'll keep reading up on this.

    Joining this site is one of the best things I ever could have done for myself. I've had to put off taking classes, due to monetary issues. This site is really helpful!

    Jennifer Moore
    JenniferLynn Productions, LLC

  • Saqib August 21, 2009 01:28 am

    Quadrangle? You mean square lol. Nice analagy!

  • Stacy August 20, 2009 07:36 pm

    Nice analogy. I think analogies are the best way to explain exposure to beginners. Seems so complex until you get it. Then its a cinch.

  • Victor August 20, 2009 04:06 pm

    Thanks Darren for the excellent tip and article. I just bought the book by Internet on amazon.com I will be waiting for the book close to the mail box for the next 6 weeks (long way to Australia)

  • Joerg August 19, 2009 07:16 am

    Thanks for the informative summary. Think you can not stress enough that a digital camera is an ideal tool for learning exposure as you get instant feedback

  • Rosita August 18, 2009 02:08 am

    Hey Darren, thank you very much for this and all what you do to help. just to help! God bless your mind, your work, your life.It is really a gift to have find you on my way.

  • lij July 27, 2009 02:10 am

    thanks a ton Darren.
    very informatiive...

  • Moos July 15, 2009 11:28 pm

    Thank you very much Darren, this was very helpful and very informative

  • jill July 12, 2009 01:25 am

    thanks it really help me a lot understanding all aspect of digital photography

  • mark varona July 11, 2009 04:05 pm

    thank you!! very informative!!

  • dokki-kidd July 7, 2009 07:05 am

    thanks for this tutorial! EXCELLENT guide to beginners like me. Keep it up... :)

  • Kelley June 28, 2009 04:30 pm


  • Kaleem Jaferi June 22, 2009 10:15 pm

    Thank you very much for all the illustrations and explainations. I have learnt a few tricks in a very short time and am looking forward to creating some memorable moments.

  • oddstray June 22, 2009 02:15 pm

    I've just started reading this, and I read the "window" analogy. Instead of sunglasses, wouldn't a closer analogy be tinting on the window glass?

  • rubberslipper June 22, 2009 12:04 am

    OMG this article has been so useful. I just bought my first DSLR camera and i'm a complete newbie. This has made me understand aperture, shutter speed and iso and how they relate to each other better and without confusion. THanks! keep the tips coming :)

  • Michael June 21, 2009 11:31 am

    Jeremy, thanks for the cheat sheet, I'm new to the manual mode and this will be helpful in my experimentation on my P& S camera. Darren glad to find this site, hope to be a fan and expand my knowledge here.

  • udo.d June 17, 2009 05:59 am

    Mukesh is right. The triangle should be a "quadrangle' with neutral density (gray) filters (sunglasses with varying strength) as the 4th dimension. I wouldn't be surprised if sometime in the near future a camera maker comes up with an "Auto Filter" feature. These filters are great if during bright day light you want to have long exposure times (motion blur) or narrow depth of field and ISO is already at its lowest setting. You would manually set shutter speed, aperture and ISO and let the camera automatically pick a filter to avoid over-exposures.

  • mseviieee June 16, 2009 08:44 pm

    Great window illustration / article Darren!

    @Jeremy Jacobs thanks for the cheat sheet :] this will come in handy!

  • Jeremy Jacobs June 12, 2009 08:55 pm

    Great article! I am relatively new to photography and this is very helpful. I prefer the first metaphor myself and the article on the Canon site is excellent!

    I have created a very simple cheat sheet that I use when taking pictured based on this. You can download it from my site and share around!


  • Ben June 10, 2009 12:20 pm


    Glad you pointed out the other element. (light) excellent.

    Nothing is mentioned about metering mode. It has a lot to do with exposure also.

  • Alex Suarez June 10, 2009 12:47 am

    @Electron - That's exactly the point I made in my earlier comment. I agree, I think the container analogy holds up better under scrutiny. Regardless, an excellent post from Darren.

  • Electron June 9, 2009 03:25 am

    I hope this doesn't confuse the issue, but there's another metaphor I've had a lot of success with in trying to explain exposure. I relate exposure to filling a drinking glass at a tap. Rate of flow of the water = Aperture; Time water is flowing = Shutter speed; Size of drinking glass = ISO.

    Obviously this is similar to the garden hose analogy, but I think the glass size is a more useful symbol. People are immediately familiar with the concept, it illustrates the role of ISO more directly, and it can be extended to explain signal-to-noise ratios.

  • Bonnie June 7, 2009 01:18 am

    Excellent example to explain a complex subject.

  • Red June 7, 2009 01:17 am

    Thumbs up for the "window" example.

  • Kenneth Hyam June 6, 2009 08:26 pm

    Hi Darren,

    This is the second time I have read this article, and I think the metaphors are very helpful.

    What I find interesting is the way the three corners of the triangle intereact.

    Thanks for the excellent insights.


  • Rajev June 6, 2009 06:51 am

    Concept beautifully explained using very nice examples. I liked the window example the best.

  • David June 5, 2009 10:09 pm

    thank u so much for all the inspiring topic in this website. i lose my passion in photography because i have no digital camera. but when i read some of the article in your website.the passion arise.. thanks again

  • Sahil June 5, 2009 06:04 pm

    Its great to read such kind of topics for a beginner like me. This helped me a lot.. I shall now move forward in this field and produce bring results.

  • jerome cura June 5, 2009 12:34 pm

    although i really found all the analogies helpful (thank you for that), is there any fixed rule that a specific setting of aperture should correspond to a specific setting shutter speed? or does it all depend on the situation at hand?

  • Richard Poi June 5, 2009 11:48 am

    Using metaphors is very effective in communication and making people understand: thank you for the tutorial article.

  • B P Maiti June 5, 2009 09:51 am

    A well informative article ,excellently illutrated My cofusions are removed.

  • Alex Suarez June 5, 2009 08:41 am

    Excellent post, Darren. It's critical for any photographer to understand exposure.

    I recently wrote about this very topic on my blog ( http://www.alexsuarez.com/exposure ). I used the analogy of filling a container with water. The analogy holds up quite well for all three variables (aperture, shutter speed and ISO speed) when scrutinized. Have a look.

  • Nehal June 5, 2009 03:22 am

    Thank you very much. I never understood ISO and aperture, but your detailed explanation, and clear demonstration makes it easy for me to understand both.
    I am getting a new DSLR next week, I can't wait to try and experiment shots with different settings.

  • Bill Antonacci June 3, 2009 10:15 am

    I really got a lot out of that tutorial and I want to thank you.

  • Randy Hunt June 3, 2009 06:26 am

    The "exposure triangle" omits a fourth factor -- LIGHT! Yes, light can be controlled. You could reduce the light by using a diffusion panel (or an ND filter). You can increase light by adding light sources.

    I think presenting exposure as a three-part equation cheats the reader out of the knowledge that they CAN, in fact, control the fourth parameter.

  • swadesh_naha June 2, 2009 06:06 am

    I am feeling problem to take potrait shot at night from my nikon p80 cam.specially when i take outdoor shot, will u plz solve this problem.

  • oliverignacio June 1, 2009 09:37 pm

    I bought and read Understanding Exposure and I must say that Bryan Peterson has explained the Exposure Triangle perfectly. It is easy to understand.

  • jhon May 31, 2009 10:04 pm

    austin_hxc has the point but i think what hes is talking about is the function and how to control or handle the three elements....

  • jhon May 31, 2009 10:02 pm

    this is a great article, a very helpful for the people who doesn't know the use and purpose of this three elements.... keep it up man....

  • Austin_HXC May 31, 2009 05:09 am

    "I get the feeling in your window metaphor you have added a new element (the fourth one) that helps control exposure… which should make Bryan’s triangle a ‘quadrangle’. Your example of sunglasses actually is fliter that you can put in front of lens to reduce the amount of in coming light. So it is not only - apertutre, shutter speed and ISO that are manipulable variables but also the light filter that helps control the extent of incoming light."

    I agree.
    But it would actually be called a quadrilateral. :)

  • Turki AlFassam May 30, 2009 09:29 pm

    Thank you! it's very important topic every Photographer should know it very well.
    I found the illustrative in this link is more easy to understand. check it out:


  • Ilan May 30, 2009 07:20 pm

    Sorry - Here is the correct, clickable link -
    For example, in this photo the WB tends to be bit yellow, to give that "early morning" feeling, and iso is pretty low, to allow me to use the correct shutter speed just to enhance they eye and the reflection, and keep everything else in the darkness.

  • Ilan May 30, 2009 07:15 pm

    This is a very important article, and important mainly because there are many people using their DSLR on Automatic mode. And that, in my humble opinion, is like buying a buying a new car just for rolling yourself downhill for fun.
    Each of the mentioned tools (iso, aperture and shutter speed) are tools that should be used to express yourself and define the exact outcome of the frame.
    For example, this photo -http://www.ilanbresler.com/2008/09/glance.html - The WB tends to be bit yellow, to give that "early morning" feeling, and iso is pretty low, to allow me to use the correct shutter speed just to enhance they eye and the reflection, and keep everything else in the darkness.

  • MeiTeng May 30, 2009 05:26 pm

    I placed an order for the book by Bryan Peterson and am still waiting for it to arrive. I picked up at least 3 reading titles from DPS. Thanks!

  • mack May 30, 2009 04:19 pm

    Yeah, the window analogy is a lot easier to understand.

  • Mukesh May 30, 2009 02:29 pm

    I get the feeling in your window metaphor you have added a new element (the fourth one) that helps control exposure... which should make Bryan's triangle a 'quadrangle'. Your example of sunglasses actually is fliter that you can put in front of lens to reduce the amount of in coming light. So it is not only - apertutre, shutter speed and ISO that are manipulable variables but also the light filter that helps control the extent of incoming light.

  • April May 30, 2009 11:08 am

    I found the window analogy most helpful.