AV mode--

julie32 · Jan 1, 2008

Happy new year!

I'm wondering what the best way to use AV mode is... i keep seeming to get very dark photos inside at 2.8, 100-400 iso.
what am I doing wrong or what do I need to do?

thank you

julie

Sideburns · Jan 1, 2008

is your exposure compensation set too dark?

Which camera are you using? Is there a thing that limits the shutter speed to only go so low?

JIP · Jan 1, 2008

Whatever setting you use you need to follow what the meter says at least to a point. You can exercise some creative control going under or over what the meter says but you need to be close.

Sideburns · Jan 1, 2008

JIP said:
Whatever setting you use you need to follow what the meter says at least to a point. You can exercise some creative control going under or over what the meter says but you need to be close.

Av is an auto mode. Unless she uses exposure compensation, it can't be that off.

julie32 · Jan 2, 2008

hey guys,
thanks for the replies. I'm new at this...i have a canon 20D, I just thought that if I was as wide as 2.8, with an ISO of about 400 inside my house, that the camera would choose the correct shutterspeed for a decent shot without flash.
Can you explain changing the exposure to me and why I'd do that versus changing the f stop or lowering the shutterspeed to get more light?

I understand how to actually change it on my camera, but I'm not sure of the "why"

thanks for your patience,
julie

Mav · Jan 2, 2008

I guess it all depends on what you're trying to shoot. For indoor shooting with typical lighting, f/2.8 and iso400 "sounds low" unless you're using really slow shutter speeds, but that's based on my own indoor shooting conditions.

Shooting my 9 month old daughter indoors, I need a minimum of 1/125s shutter speed to avoid tossing too many photos away due to motion blur. I can pull that off at iso1600 and f/2, but then I have relatively noisy photos due to the high ISO, and lose a lot of shots due to focus errors since there's little depth of field at f/2. I prefer to shoot between f/2.8 and f/5.6 (usually f/4) which gives me enough depth of field to avoid focus errors but still tight enough to get some nice blur in the background to make my daughter pop out a little. But short of having a camera body that would give me clean and detailed results between iso3200 and 6400, that means I use a flash and shoot at about iso400 instead.

Ususally I shoot in Manual mode (typically locked at 1/125s and f/4) and let Auto ISO on my Nikons figure the rest of the exposure out, along with the flash. Works great. In Av mode on a Canon, if you get consistently dark shots, just hit the exposure compensation button and increase it by about a stop. In Av mode, it'll do that by lowering the shutter speed. You'll just need to watch that your shutter speed doesn't get too slow for whatever you're shooting or the focal length you're using and end up with blurred photos. If you do, you can either use an even larger aperture like f/2 if you have a prime lens, or crank up the iso by a stop to 800. f/2 will give a tighter depth of field with less in focus which may or may not be appropriate, and iso800 will be noisier which may or may not be acceptable. It all depends on what you're trying to shoot, if it's moving or not, what focal length, how much you want in focus, etc...