ok I'm new and I am trying to figure out the exposure triange

[vickistark]

so hypethetically if I want to take a sharp night shot of city streets with streetlights on and a bright moon shining that is illunimating the cloud formations overhead and I have a tripod and I want it all in focus would it be corret to choose ISO 100 shutter speed f 1/30 aperture f2.8? I just want to see if I have this correct in my mind.

[natek313]

Possibly, but not definitely. It just depends on how much light there is in the scene to begin with.

But, I can tell you that an aperture of f/2.8 won't get everything in focus. At an aperture that large, you're looking at a fairly small depth of field. If you want more in focus, then you're going to need to use a smaller aperture which will force you to bump up your ISO or slow down your shutter or a combination of both.

Sorry for such a vague answer, but there's really no definite answer to your question. My suggestion would be to go to the location you want to shoot and take multiple shots; change settings between shots to see how it affects your exposure.

I hope this helps.

[vickistark]

ok so a large aperture creates a short dof? Like I said I have no idea what I am doing and trying to get this straight in my head. It seems there is so much to remember and I find it all too confusing. Is there a trick to remembering wht it all means aka exposure triangle for dummys lol

[vickistark]

thanks for responding to me. I appreciate that. When I say I am new I mean brand spanking new to entertaining the idea of taking my cameran off auto mode! I have a Sony DSC h5 digital camera but I have an old 35 mm camera that I'd like to play with unitl I can upgrade to a DSLR. I thought if I could get comfortable with it and the manual settings that it would make the transition smoother when the time comes. I believe the 35mm is a practika and it also has a telelphoto lens but it is not in front of me at the moment so thatis about all I can say.

[KJPino]

Really the best thing (and the most fun way to learn) is to do exactly the suggestion above - get out there and take shots and change settings and see how the images respond... nice thing with DSLR is that you don't neccessarily have to take notes (althought they do help) because the digital image recods what settings you used so you don't have to remember - but do make note (even if only mental note) of the scenario (like light intensity and direction - like back light, low setting sun, etc.)...

the basic concept you have kind of stumbled onto about aperature is one you'll probably learn quickly - the most confusing thing in the beginning is to remember that larger F-Stop is smaller aperature... but for DOF you can kind of think of it like this... the larger the aperature the faster everything comes in so you give the camera less time to caputre all those details in the full frame... the smaller the aperature the longer the exposure needs to be so the camera has more time to gather all the details in a greater area of the exposure...

That explanation is just a simple way to keep it straight in your head that worked for me early on... it basically explains the outcome as opposed to explaining the process - but hopefully it helps you with how to decide if you want large or small aperature... both have their uses and can be fun - especially if you take identical shots with different aperatures and see how it directly affects DOF...

Hopefully some of this helps... now go take pictures and have fun! Taht's the real secret - don't make it work - just enjoy and you'll start to notice as you play with the settings how each affects the final product... and don't get frustrated - digital images are free - take lots... 100s... you can always delete the ones that don't look good and it cost you nothing...

[vickistark]

thank you thank you that helps......a little. hahahahha

[SandeeWig]

The way I worked through the triangle relationship, was to start w/ aperture then adjust SS, and if necessary ISO until I got the proper exposure.

Aperture: low # (i.e. f/2.8) = short DoF; high # = long DoF
(in my mind, low and short correlated easily)

Consider what I'm shooting and select the aperture I want. Average, for me, would be f/5.6-f/8.

From there I start at ISO 100 and SS 1/100 and check the exposure.

If overexposed - increase SS 1/250, 1/500, etc. until properly exposed*
If underexposed - decrease SS 1/80, 1/60, 1/50...at this point I would try increasing ISO to 200 or 400 and see if I get proper exposure, because I know that at 1/40 or slower I'm going to have a problem with handshake or motion blur.

*If in bright daylight, and you reach the maximum shutter speed and are still overexposed, then you'll have to narrow your aperture (higher f/number).

The key is to remember that whatever you have constant (e.g. aperture), changing one of the other two is going to let in more or less light. I like changing SS if I can, because the higher the ISO, the grainier the image.

I hope that helps; I tried not to be too wordy.

[vickistark]

cool, thanks that sounds like a plan to me.