@jfrew wrote:
Thanks Bob,
Contrary to your response, I have read the manual and found it quite easy to follow since I have owned EOS cameras for years. I was assuming that the responses I would get from the forum would be helpful as opposed to sarcastic and degrading.
Good. Then you understand how ETTL flash works. As you know, the algorithm assumes that "all flash is fill flash". So the camera meters for the background, and the flash fills in the darker foreground areas with no blown highlights. Because the background lighting is unpredictable, the camera may have to use heroic measures, including changing the ISO speed (assuming that auto-ISO is active), to get it right. When it can't, you can have situations where only the highlights are properly lit. You've undoubtedly had that experience when trying to use ETTL flash outdoors at night.
The usual way to compensate indoors is to use bounce flash, with or without the diffuser plate in place, to even up the background lighting. Since you're now relying primarily on the flash's ability to shut off at the proper illumination level, it can help to use manual exposure with a default setting (e.g., f/5.6 or f/6.3 at the sync speed), thus giving the flash full control. ("Full control" is a bit of an oversimplification, of course, since both the camera and the flash are in communication to match the manual setting to the flash output, but you get the picture.) In the absence of the manual setting, the camera is likely to choose an aperture that's too wide, or a shutter speed that's too slow, to provide an optimal result.
I apologize for my flippant response to your initial post. But in my defense, I'll just point out that when you ask like a newbie, it's likely you'll be answered like a newbie. Otherwise, people accuse us of deliberately showing off our command of technical jargon.
Bob
Philadelphia, Pennsylvania USA
