DOF Issues Using Flash

I've always been a landscape photographer and although I've had my 580EX for some time I have hardly used it. The other night I was at a club taking some photos at a party I was at. It was all OK apart from the fact that everything was at f2.8 which meant that if there was a row of people and one of them was slightly forward or behind they were out of focus...

I've tried reading the stickies and a looking at a few other forums but I think that I need a bit of an idiots starter for 10 about how I am able to shoot in really dark conditions using the flash at something like f5.6.

I now it sounds like a dumb question but I'd appreciate some help!

Thanks

Are you wanting to expose any of the background? If so, put your camera in manual, aperture at 5.6 set your ISO such that you get an exposure that's about 1 to 2 stops under. Set your flash to ETTL and experiment with FEC (flash exposure compensation).

IainUK wrote in post #13109993
I've always been a landscape photographer and although I've had my 580EX for some time I have hardly used it. The other night I was at a club taking some photos at a party I was at. It was all OK apart from the fact that everything was at f2.8 which meant that if there was a row of people and one of them was slightly forward or behind they were out of focus...

I've tried reading the stickies and a looking at a few other forums but I think that I need a bit of an idiots starter for 10 about how I am able to shoot in really dark conditions using the flash at something like f5.6.

I now it sounds like a dumb question but I'd appreciate some help!

Thanks

Are you trying to match the flash with ambient light?

There could be a few ways to approach this:

Bump the ISO up. If you're using auto ISO then take it out. This is going to increase noise in the final image, though.

If you don't care about the background going dark then just crank the aperture to 5.6 or higher. A good flash should have enough power to handle it. If the camera slows the shutter way down to compensate for ambient, then you may want to shoot in manual. Set the shutter for your focal length and the aperture where you want. If flash in in E-TTL mode, it will expose right. The background will be dark, though.

Or, you could go the "more power" route and add another flash into the equation. Not realistic to some, but it's how I justify buying more stuff to my wife.

Maybe you're overthinking this.
Turn the dial to M.
Set your aperture at f/5.6.
Set your shutter at 1/200.
Take your shot.
Adjust exposure with FEC.

For more range, faster recycle and longer battery life, crank up the ISO.

^^^ What he said. I'll add that if you want to have more ambient light in the background, slow the shutter down 1/60 or what have you.

you can also bounce the light if there is a ceiling.

A classic case of the camera making the decisions for you.. Take control of your camera.

Check out Curtis' post

Indeed, hence the post

I think over thinking it is right. I did move to manual but I couldn't quite get the shutter speed right-looking at the posts it may be due to having the ISO set to A.

I wasn't worried about the background being dark to be honest - It was mainly the people I wanted to capture. The only exception was when I wanted to take a wide shot of the whole party from a stage.

I really appreciate the input - it was exactly this sort of advice I was after. I'll go and experiment.

I suspect you are trying to use AV or TV mode on the camera. That will cause the camera to try to set a proper exposure without the flash. Put the camera on M and set it as Curtis suggested. Don't worry about any meter reading that your camera may provide. It will be telling you that the scene is under exposed, but you already know that. That is why you are using the flash. Set the flash on EETL, the default setting unless you have changed it. Shoot away. You won't necessarily get great art, but you will get decently exposed images if you aren't too far away. If they are coming out over or under exposed, you can adjust the flash exposure compensation (FEC). If you can't figure out how to do that, then post back here and someone will tell you.

IainUK wrote in post #13113605
I did move to manual but I couldn't quite get the shutter speed right-

I have a hunch you're looking at the meter in your viewfinder.

Like Jim said, ignore it.

Curtis N wrote in post #13114277
I have a hunch you're looking at the meter in your viewfinder.

Like Jim said, ignore it.

+1

case in point, when I took this shot, the 50D said I was underexposed beyond 2 stops. but I set it to -1/3 on the 580EXII, 1/50 sec @ F/5.6 ISO400.

Yes it was the viewfinder and I kind of knew to ignore it because of the conditions I was in....I didn't try TV or AV as I had read previously that those wouldn't work. It was M that I could quite get..

Right - I'm going to experiment.....I'll be back with some images. Thanks again!