Does the flash metering override the camera metering MODE?

[keithallenlaw]

I tried all the metering modes today on both the 30D and the 5D with flash and the histograms where all identical.
Even tried different subjects except for back lit ones. Will try that one.

So would it be fair to say from this experiment that the flash meter is subject related. Perhaps spot metering of some sort.

[jfrancho]

Well, it isn't so simple as that. I hate doing this, but two things I think you should read, the EOS Flash Bible, and the flash videos at photoworkshop. On photoworkshop.com you'll find a video called EOS Speedlite Tips in the bottom right panel. The Flash Bible is a gigantic hunk of text that may take a few days to digest. The short answer to your question, though, is that metering is set on the camera, C-Fn. 14. "0" is evaluative, and "1" is average. I use evaluative. The camer meter works the same, regardless of whether the flash is used or not, although there are other custom functions that may dictate the camera's behavior in auto exposure modes like P, Av, and Tv. Remember this: Flash Exposure Compensation controls subject exposure, camera settings (Aperture, shutter, and ISO) control background exposure. Deal with each seperately, and the ETTL-II mystery starts to unfold. Good luck.

[keithallenlaw]

Why would you *hate* to do this? I am most grateful for your time and effort to afford me the chance to learn something new. Thank you for the links! Cheers...

[jfrancho]

That Flash Bible could be used to interrogate suspected terrorists.

[keithallenlaw]

Originally Posted by jfrancho

That Flash Bible could be used to interrogate suspected terrorists.

I haven't got that far but I did check out the first link. I got side tracked on this thing called Lightsphere II.
Looks very interesting.

[jfrancho]

Run as fast as you can!!!! Just kidding, I think if it had a sealable bottom it would be great...for bringing soup to work for lunch. But many others swear by them, and I think in certain situations, they may be the best. I get the most consistent results with an index card and a rubber band. Look up "a better bounce card" as well - that works pretty well, too.

[keithallenlaw]

Originally Posted by jfrancho

Run as fast as you can!!!! Just kidding, I think if it had a sealable bottom it would be great...for bringing soup to work for lunch. But many others swear by them, and I think in certain situations, they may be the best. I get the most consistent results with an index card and a rubber band. Look up "a better bounce card" as well - that works pretty well, too.

LOL...OK, I will do that.

[keithallenlaw]

But the Nikon post below me where I originally posted this is OK? Humm...That seems product specific too.


http://www.photocamel.com/index.php/...html#msg151378

[jfrancho]

I wouldn't sweat the move - you'll probably get some better answers by tomorrow. I'm thinking he moved it because although it involves lighting, it has more to do with the way the camera functions. The Nikon was specifically a flash related question, but a judgment call could be made to move it too. Hopefully Max will pick up the scent on this thread, and have a good answer to the original question.

[Max@Home]

Hi Keith, Hi John,

Originally Posted by keithallenlaw

I tried all the metering modes today on both the 30D and the 5D with flash and the histograms where all identical.
Even tried different subjects except for back lit ones. Will try that one.

So would it be fair to say from this experiment that the flash meter is subject related. Perhaps spot metering of some sort.

Originally Posted by jfrancho

Hopefully Max will pick up the scent on this thread, and have a good answer to the original question.

hoohoo ?? The hills are alive with the smell of Bactrian ??

AFAIK and understand the Canon Flash system, with ETTL-II (5D and 30D) the camera and flash cooperate to get the subject (what they perceive as the subject) well-exposed and lit.

For this reason there is amongst other exchange of AF distance to the flash, etc, etc, So the same scene, with exception of a back-lit scene, should get the same histo in all metering modes.

With back-lit scenes, spotmetering on the subject will give the best exposed subject, but will blow the back-lit, or you can meter for the scene (so the back-lit doesn't blow) and use fillflash to get enough light on the subject/bring it out of the dark

...hope this makes some sense, *my* €0.02 worth...

Kindest regards,

Max@Home