How to Choose the Right ISO for your Digital Photography
“What ISO is best for my pictures?”
Changing the ISO setting on your camera changes the sensitivity to light of the image sensor inside of it.
The lower number that you select the less sensitive the sensor is to light (and conversely the higher the number the more sensitive it becomes).
This is useful when you’re shooting in different lighting situations - particularly when there’s low light and you might not be able to use a flash (you’d bump up your ISO setting in this case).
The only cost of increasing ISO is that as you do it you’ll notice that the ‘noise’ or ‘grain’ in your shots also begins to increase.
You probably won’t notice this graininess on your images when lookin at them on the LCD on your camera - however when you get them back to your computer they’ll become noticeable with higher ISO settings.
Here’s an example that I’ve used previously with two images taken with exactly the same settings except for the ISO (100 on the left, 3200 on the right).
As a general rule you should choose the lowest ISO possible for smooth and grain-free shots.
6 Questions to Ask to Help Choose the Right ISO
Of course when photographing low light scenes there may be no other alternative so I’d suggest asking yourself some of the following questions when choosing what to set ISO at:
- Am I hand holding the camera? - when using a tripod you might be able to use a slower shutter speed which would allow you to lower your ISO.
- Is my subject moving? - if your subject is perfectly still (like when shooting a still life) and where you’re using a tripod you’ll be able to slow your shutter speed and lower ISO.
- Do I need a big Depth of Field? - If you don’t need a large depth of field you might be able to increase your aperture which allows more light into the camera and will allow you to lower ISO.
- Can I use some Artificial Light? - using a flash or even switching on a light can help to get more light into your camera - allowing you to decrease your ISO setting.
- Can I get away with Grain? - sometimes a photo can actually look better with grain. Some photographers love the mood and atmosphere that a little noise can add and will bump up their ISO in the hope of getting it.
- How big will the image be enlarged? - the reason that noise is not able to be seen on your camera’s LCD is that it is very small. As a result the pixels in the picture are small also and the grain is unable to be seen. It is only when you enlarge the picture on a larger screen or in printing that it becomes noticeable. If you’re only ever going to use the shot in a small size you can probably get away with a higher ISO.
Keep in mind that it’s only when you shoot in a manual or semi-manual mode that you need to change ISO. When you’re in auto mode or one of your camera’s preset modes it will select the lowest one that it can for you.
A Word Of Warning on Changing ISO
Also keep in mind that if you change ISO that you will need to get in the habit of checking what setting is selected at the start of every photo shoot.
Many photographers have been disappointed at the end of a shoot to find that they’d forgotten to check what ISO setting they’d left their camera on in their last shoot. There’s nothing worse than thinking you’re shooting at an ISO of 100 only to find you forgot to switch it back from 1600.
To help with this always check your ISO setting before starting to shoot - but also try to always switch it back after a shoot.
Have Your Say
Do you change ISO settings much in your photography or rely upon auto mode?
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Very good tips. I have had that happen, a great shoot, great lighting, still camera and objects, eprfect for lower ISOS and did the whole thing on ISO 1600, I was really upset about that.
I don’t think I can agree with the last sentiment enough - I can’t tell you how many times I’ve forgotten to check my ISO and then kicked myself when I discovered that my camera was at ISO 400 or 800 for a whole shoot.
On the bright side, Photoshop can do a pretty good job of clearing up the graininess, though you lose detail when you do that.
My advice is to get in the habit of putting the camera back at a low ISO when you’re done shooting; you can’t trust yourself to remember to do it before the next shoot.
Great information. I really enjoy your blog. I read it everyday but don’t always have time to comment.
Nice tips! i already knew some of them though! :) , ive seen many firework shots which looks good but have lot of noise!
Totally agree with Eric, there has only been one instance I have been happy with the end result when I had accidentally left the ISO high.
When starting for the day I now always check the ISO, and the exposure compensation.
This also applies if I have been inside a building/ cave/ tunnel, etc and then come out into the sunshine to start shooting different scenes.
Having recently gone through a similar faux pas of leaving my camera on a high ISO setting then finding a day of shooting at a hard-to-reach location had been spoilt, i started looking at ways of solving the calamity in post-production.
There’s a couple of solutions out there, but all can help salvage that ruined photo into a more friendly state. I’ve been playing around with a free tool called ND Noise with some very peasing results. Other tools can be found with a google search for ‘Noise Reduction Software’ or something similar.
One large review of such tools can be found at: http://www.michaelalmond.com/Articles/noise.htm
When photographing the Light Parade at Disneyland,I was disappointed to find that there were streetlights and other object that interfered with the shots at 400 ASA. The following night I returned and shot the entire parade at ASA 3200 and found the results were startling to say the least. The lights and the characters on the floats were captured against a near black background - as if they were floating!
Great article, I too have suffered the embaressment of having done a whole shoot on ISO 3200, it was a wedding and the internal shots had to be flashless, so I bumped the ISO, then forgot to drop it down again!
I used a bit of software called “Noise Ninja” which was amazing it cleaning everything up - it’s not a replacement for actually shooting at the right ISO in the first place, but it helped me out.
Since then, I’ve painted “CHECK ISO” just below the viewfinder - making sure it never happens again!
Yah I found that a problem with the interface of my old D70s, it didn’t show ISO in the viewfinder or on the top LCD, so I found myself sometimes wrongly shooting the whole day at ISO800 from the previous night.
Noise Ninja and Neat Image are pretty good though.
I did an article on ISO a while back:
What is ISO or ASA - Camera/Film Sensitivity AKA Filmspeed
I work for a small newspaper and in the winter i shoot a lot of indoor sports (hockey, volley ball). I need to use a fast shutter speed to freeze the action but the lighting is usually so dim so i find myself cranking up the iso alot. How do you know how to balance iso with what you will be able to do in photoshop later. Which adds more noise, a high iso or playing with levels and whatnot in photoshop?
There a few golden rules to remember when shooting in different photographic climates. Sport for example. I still use ISO 400, even for bright daylight when shooting soccer and baseball…the results are excellent. Yet at the end of the game and using fill in flash, I go back down to 100 to 200 iso. Experiment as much as possible, WITH the camera and lenses you regularly use, to see what works for you.
Great- You cleared up a big question mark when it comes to setting ISO with today’s sophisticated Digital cameras
I realy enjoied reading this article because it uses a much simple way to explain things. In other words, it makes things easyer for beginers. But a corelation betwen the ISO numbers and the answers to those question will be even more helpfull like i sayed here: http://www.photoaxe.com/how-to-choose-the-right-iso-for-your-digital-photography/
Using both the Canon 30D and 5D and L-glass lenses, we find that we can routinely shoot at ISO 1600 if we process the images using Imagenomic NoiseWare Professional plug-in for Photoshop CS2. When printed in sizes as large as 17 x 22 using an Epson 3800 Pro printer and the ColorBurst RIP, any noise is essentially undectable in the prints without any noticable degradation of the image detail.
does putting filters on your lens help with clearer pictures as what i find that when i take landscape shots they just seam to be lacking clarity , even when i ajust
ISO etc camera is a canon 400
Does changing ISO actually change the sensitivity of the image sensor? Seems more likely that it just changes the exposure. In other words, setting a higher ISO raises the shutter speed, reduces the apeture, or both so as to let less light hit the sensor. Or am I missing something about digital sensor function? Thanks.
@pbean:
yes, increasing the ISO does increase the sensor’s sensitivity to light, so that allows you to close the aperture or drop shutter speed accordingly (or, in reality, to let you get an acceptable handhold shutter speed). the higher the sensor gain, the more susceptible to noise, though this does vary from camera to camera, and sensor to sensor (you should see ISO 1600 and even 3200 shots taken w/ a Canon 5D…).
cool said :)
thank you very much for the tip. Now I’m less confused.
Once school starts (and the newspaper season with it) I leave the ISO at 1600 since that’s what I’ll use most often. I can live with shooting a flower at 1600 wen I wanted 100 more than trying to shoot volleyball at 100 when I wanted 1600.
I can remember not too long ago I was shooting a prom and was doing some low light indoor shots and I forgot to change the ISO from 800 to 200 when I went outside. The pictures came out ok but I was kicking myself. I try to shoot everything at 200 or 400 on my Nikon D50
http://www.petelanglois.net
Sweet. This post just reminded me to change my custom WB before shooting today! Whew.
And, yeah, I’ve left it at a high ISO once… haven’t forgotten since. Also, I think it helps that I shoot in Manual, as I’m more likely to sporadically check the ISO, too.
I always shoot low ISO. I just fear noise. I didn’t realize my problem with noise when I wasn’t checking ISO and ever since I’ve got it dialed down. I’d rather have a darker image, or set the camera on something rather than having a brighter image with a bunch of noise. When I’m not going artsy it’s just annoying to me.
If I want some artistic noise I’ll take it into Adobe ® Photoshop ® Software.
I’ve had to force myself to get into the habit of changing my ISO back to an average setting before putting the camera away. I have ruined too many shots by forgetting to remember to do it before shooting.
I also have had a hard time learning to remember I have the ISO option. I am too eager to reset the aperture or shutter speed that I don’t even consider changing the ISO to help. I’m getting it, though. I’m getting it…
i have always try to shoot in the lowest POSSIBLE ISO setting. If you want noise, you can always add it in photoshop…
most of the tips are known, but i wish if some one post, how to choose ISO, in what condition which ISO is good at what sutterspeed. I am in learning phase and i have trouble with selecting iso, sutter speed adn aperture. IT wold have been great if some one with example show the relation of these 3 at very low light. eg. 60 watt bulb glowing room, full moon outdoor etc.
I mostly rely on my Canon EOS 40D’s auto mode. On rare occasions, though, when I know I’ll be cropping a shot later in PP, I’d set a low ISO to avoid digital grains, or noise if you will.
Of course when I’m shooting in manual mode, I set the ISO myself. It wouldn’t be real manual mode if I wouldn’t, would it? :)
I’m very comfortable shooting at ISO6400 and above now as the Nikon D3 handles noise so damn well. I only use that insane ISO 25600 level when absolutely desperate for captures handheld in abysmal light.
I still have learned to check the ISO on the back lcd before every shoot though. While the D3 has a brilliant dynamic range, overexposure freaks me out more than noise.
I always set the ISO to the lowest possible. I start with the ISO 80 for bright conditions and 100 or 200 for darker condition and then increase it if required. But I hardy shoot at ISO 400 and above.
For tricky light condition I usually select the aperture priority mode and then adjust the aperture and ISO to get the right exposure, leaving the shutter speed to the camera to decided.
I don’t have an SLR, I shoot with a canon powershot S5. I’ve recently gotten into shooting exclusively in the manual mode. I set the ISO as low as possible, which for some nature photography or macros is down to 80. Otherwise I try to stay below 400 because noise is really noticeable with this camera. I can go up to 1600, but the only situation recently that prompted me to do that was photographing dark nasty clouds without a tripod.
I try different ISO settings all the time when I take pictures. I’ll try a bunch of different shots with different ISOs so I can choose the best out of the bunch later on. With practise, I’m getting better at finding the best ISO for different situations.
@sangesh
There is no rule of thumb. You could be in the same conditions, and on three different cameras, you would need three different ISO, shutter, and aperture settings.
I have a Kit lens with my Nikon D60, and a lens I bought specifically for low light shots called the Nikkor 50mm f1.8. With the Kit lens, I have to use high ISO just to get something visible. With the 50mm f1.8, which is designed to let in more light, I can use much lower ISO.
The way I do it is this, for average to low light:
1. Go to aperture priority manual mode (”A” on Nikon)
2. Set aperture to lowest number possible (f.18)
3. Set ISO to lowest number possible (ISO 100)
4. Let the camera automatically pick the shutter speed
5. Check the result. Usually it’s too blurry and more bright than it needs to be. Note what shutter speed the camera picked (usually it’s too slow for people, like half a second).
6. Now go into full manual mode (”M” on Nikon), and slowly increase the shutter speed from that until people aren’t too blurry. Then if needed slowly increase the ISO until the picture is not so dark.
Tip: It’s ok if pics are a *little bit* dark, I increase exposure in photoshop later.
Tip: ISO 1600 and higher looks like crap. Avoid.
This is what I do for parties and concerts. As the article said, if you’re taking pictures of still objects, just use a tripod, then you don’t have to worry about any of this (just use ISO 100 and a long shutter speed).
I always am fiddling with the ISO speed, trying to keep it as low as I can. I can’t recall increasing the ISO to add grain, and I usually remember to reset it after shooting in the dark now.
I’d also add that grain becomes a lot more visible when you add contrast in post-production. A photo that looks fine before editing can look awful once you’ve livened it up. Noise removal software has come along way, so you can blur the noise out without losing much detail. I use Noiseware, but Noise Ninja is great too.
I too have made the mistake of leaving ISO high.
Now, to ensure that all settings are back to default, I normally use the reset buttons before a new shoot. Not sure if all cameras have them, but both of my Nikons do (D50 & D300). If you have a Nikon DSLR, it is the two green dotted buttons, usually far apart so as not to reset by accident.
I forgot to add:
Some of the newer DSLR’s have a great auto-iso feature, which would be good for achieving a high minimum shutter speed for sports, or a minimum shutter speed for handheld shots. Basically you tell it what the minimum shutter speed you’d like to use, and if the light is not available it will increase the ISO only when necessary. I believe you also give it a high limit in case you cannot afford too much noise, and that it will always default back to the lowest setting when possible.
(If I have messed up the description above, please correct as necessary)
@ “Have Your Say - Do you change ISO settings much in your photography or rely upon auto mode?”
When shooting digital images I change ISO to suit the lighting conditions in concert with the particular assignment and occasionally how “artsy” I want to get with an image. Like the ability to vary the white balance point changing ISO is one of the dream features of digital imaging. ISO change is a tool in digital photography, not a toy. If shooting with my strobe I never change ISO (we used to call it ASA), Fill Flash is a different story because one is balancing nat light against strobes.
As for the second part of the author’s question to us, my advice is to NEVER use the “Auto ISO” mode if it is available on your camera. Turn it off and break off the knob that turns it on so you never even accidentally put it back in the auto mode.
If one shoots film changing ISO will give disastrous results unless you know what you are doing and do it by design. Don’t do it unless you are having your film push or pull processed and keep it at a constant setting from first exposure to the last.
Bilka
@ nariposa
thank you
I think the Auto-Iso feature in the newer cams is just great as you can set a maximum limit for the ISO when it chooses to go Auto. i use it effectively depending on the surroundings (Max Auto-ISO set to 1600 in case of Photogrpahy in night clubs and then changed and notched down to 400 in case of outdoor photography by day/evening)
I never have to worry usually as the best ISO is picked out automatically by the cam
I am always trying different ISO’s. I like to see what looks the best. It is vital to remember to change it back.
Good tips. I use a Canon Ixus 950 IS, but I do fiddle with the ISO according to different kinds of lighting. Normally, I use higher ISO and longer shutter time in dark places.
I never knew about the grain effect caused by higher ISO. This is new!
Has anyone tried shooting the moon under a clear night sky? It’s quite hard. Any tip?
I usually have my ISO at it’s lowest. I’m quite steady, so I can go with longer exposers than most people, when shooting free-hand (is that the correct term?).
I only bump up my ISO when I can’t reach enough exposure when fiddling with app. & shutter speed.
I like noise on certain pics, but I’m one of those people who like to add it in post-production, just to be on the safe side
i change iso often, and yes i have blown out some images! hahahaha, but i’m old and forget easily. i shoot alot of sports, and sometimes it can be cloudy, then 5 minutes later, its full sun light! since i shoot aperture mode, iso is my best friend! awesome post! and very informative!