Adjusting for Flash in Manual

I was talking to Casey today and wanted to post this up because we figured it would benefit all.

I've had trouble in the past (and still do) adjusting for flash while shooting in manual. Of course my light meter says I'm going to be underexposed, but when the shot goes off it's either overexposed, perfect...etc and I'm constantly adjusting with multiple picture to get the combo right.

With that being said, I'm not always going to have time to constantly adjust.

As well, there are sometimes when I want to use flash to fill the background, yet I just end up lighting up the main subject more than what I intend...and run into the same problem again.

I guess I just need an overall education session on using In-Camera flash.

Overexposure is kind of peculiar. The way it is supposed to work is the camera meters the scene and uses the info to adjust the output of the flash to compensate. Underexposure is common when the flash simply doesn't have enough power to compensate or there is backlighting but overexposure means the camera isn't metering the scene correctly. *

On a Canon you can adjust the metering from 'evaluative' which meters the whole area, down to 'spot' which meters the center 5%. I'm sure all brand do this but with different terminology. You can see how if you were taking a picture of someones face and there was light coming through a window behind them evaluative would underexpose the persons face as the window would throw off the metering. Spot metering would just meter the center and should correctly expose the persons face.

It might be helpful to get out your trusty coke can and do some test shots. Placing it in the middle of a dim room with any lights behind the camera should be an easy one for the camera to correctly expose and try different ISO settings and metering modes to see the difference they make in the overall exposure and particularly the difference in background exposure. Once you get that figured out you can try a lamp in the scene - slightly more difficult, or a window in the background - much more difficult.

William.

* edit - Outside of something wrong with the camera, it will always meter correctly. I should have said the camera wasn't metering the way you wanted it to. As in, you and the camera disagree on what is important in the picture :)

Quote:

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Originally Posted by wsmeyer

It might be helpful to get out your trusty coke can and do some test shots.

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Could not agree more. Casey always says that. Practice. Test. Practice.

All dSLRs I believe are capable of through the lens compensation like William explained above. My explanation would have looked very similar to his, so there is no point in beating a dead horse. I think your issue Kyle is coming from the way you meter. Fill light, is by far the trickiest type of light to get right when there are multiple sources of light introduced in a shot. As suggested, a Coke can doesn't care how many times you flash it in the eyes, nor does it move, get cold, or complain. The perfect test subject.

:word

Ok, took some shots. I'll get them up here so you can look.

I guess I had the idea of flash completely wrong, for some reason I was thinking that flash took a 1-2 second exposure so that it can be shot handheld. That isn't the case. Dumb Dumb thinking on my part...such a noob

There is an instance on one of my shots where it metered correctly and the shot came way overexposed. Is this a meter problem? I had it on meter matrix, not meter spot. I metered to the light behind the subject, then adjusted shutter and ISO and shot my subject. However, when I focused my camera on the subject, my light meter flashed way underexposed and wanted to adjust shutter. I kept it the same however knowing that my adjustments were correct, and shot it...That's how it came overexposed.

Makes sense? Was the camera thinking I needed more light when I didn't?

I dont usually trust my in camera meter. I'm not an expert on the subject but I believe it measures more for light/dark spots in the frame more than actual light. If you have a well lit subject in a totally blacked out frame, it will most likely tell you it's under exposed because of the overwhelming amount of black, even through it might be perfect lighting. Same thing with a dark object well lit in a super white background, it would say its overexposed. If I am using a light source other than available light, I use a real light meter to get my readings from. If I'm shooting w/ available light only, I'm comfortable enough knowing about where I should be in association to what my camera's meter says and what I'm shooting.

When in doubt, under expose a little... a lot of my shots come from around -1 on the meter when I'm weary of the actual reading I'm getting in camera, and end up being VERY easily corrected and slightly brightened up in post production. It's not as easy if they are over exposed, actually it's almost hopeless if its over exposed. Think of it like a steak; if you cook it too much, it's burnt and well done... no coming back from that. But if you under cook it just slightly, you can always go back and cook just a little bit more to get it right where you want it. That being said, if you under cook your stuff too much, you'll be there forever and unfortunately post production can't take a black photo and make it bright. As long as you hit in the range that you're getting a reading on the meter in camera, you should be ok to fix it but 99.9% of the time I'd rather be UNDER that 0 mark rather than over it.