getting ETTL to work with program auto

[mediyoga]

Hi folks.

1) When I use my 580 on the rebel I go manual for indoor shots- 60 and F 9-12 depending on the lighting. I get good shots, well exposed. I have to keep the flash on Manual and output 1/1 on the flash.

2) If i use ETTL with aperture priority, I get good shots indoors too, though the flash goes to slow sync ( again avoided by fixing it to 200 in custom settings- but this also underexposes sometimes).

3) However, if I use ETTL with program auto, the shots are horribly underexposed. I know we have to stay away from program auto for indoor shots as the program auto does not meter the flash.

4) Does this mean that one cannot use ETTL indoors at all?


I have read and am reading again the phtonotes on EOS flahs photography.
Thanks for all guidance
Krishna

[cdifoto]

Flash Exposure Compensation. My default is +2/3.



Read your flash manual to find out how.



PS: f/9 is stopped down aweful far for an indoor shot. Are you shooting groups? If not, try to stay as wide as you can on your lens. It'll keep the flash from using all of its power. Also it sounds like you aren't increasing your ISO. Set it to 400 for better results.

[mediyoga]

Thanks CDi/. I am not shooting groups in particular, but experimenting , should the high speed sync be enabled on the flash too? I did this and found that it made a difference.
Krishna

[cdifoto]

You can turn it on and leave it on with the 580EX. It'll "shut off" when the shutter speed goes too low and "turn back on" when it goes higher. I think it always shows the H regardless but I could be wrong. I just shoot without paying attention to it. I don't think it'll work properly though if you have the 1/200th custom function enabled for Qv mode.

If you aren't shooting groups, you really don't need to shoot at f/9-12. Unless you want the whole room to be in focus. Otherwise, open up your aperture and it'll put less strain on your flash unit. Increase your ISO to do the same.

[mediyoga]

Thanks. Did the increment increase on the flash to 1/3 and that did the trick along with iso 400.
Krishna

[cdifoto]

Thanks. Did the increment increase on the flash to 1/3 and that did the trick along with iso 400.
Krishna

Keep an eye on your histogram too because Flash Exposure Compensation is the only way to control the flash output. You'll find yourself adjusting it quite a bit to get proper exposure. If you aren't familiar with the histogram, read up on it in your camera's manual. Don't judge exposure by the LCD...it's not accurate.

[mediyoga]

I think you are online too. Yes . I see the histogram also. Yeah the lcd is useless. BTW you use flash increment of 2/3, + iso 400 and aperture less than
9 ? Does it not overexpose?
Krishna

[cdifoto]

I think you are online too. Yes . I see the histogram also. Yeah the lcd is useless. BTW you use flash increment of 2/3, + iso 400 and aperture less than
9 ? Does it not overexpose?
Krishna


Yeah I'm online too. I'm bored. hah.


No it won't overexpose. That's what E-TTL is for. It calculates flash exposure automatically. Outdoors in daylight you need to be more careful and meter properly because your flash is just for fill then, not a main light. When you're indoors, its rarely that bright.

Your camera is metering for the natural light. If you can't get a proper exposure WITHOUT the flash and a reasonable shutter speed, your shot will NOT be overexposed WITH flash unless you have FEC set too high.