I am attempting to use an EOS-3 with a Sigma EF-430 Super flash and am hoping someone may be able to offer some insight as to why things are working the way they are.

The flash, which is eTTL compatible works perfectly in Program mode regardless of ambient light intensity, however, in either AV or TV modes and in low light situations the flash fires correctly but the shutter stays open for too long a period. With a small aperture the shutter can stay open for up to 8 seconds. Setting the shutter speed at 125 and various apertures in Manual also works perfectly. Am I attempting to do something the camera is not capable of doing? Do I have to shoot all my flash pictures in Program mode? Do I really NEED to drop $350. for a Canon 550EX?

Any help or insight would be GREATLY appreciated!!

-- Bob Bies (bbiess@yahoo.com), December 27, 2001

Answers

The flash is behaving the same way a 550EX would. In Av and Tv modes the flash meters for ambient light. The EOS flash FAQ explains further:

http://bobatkins.photo.net/info/faq30/flashfaq.htm

-- NK Guy (tela@tela.bc.ca), December 27, 2001.

>In Av and Tv modes the flash meters for ambient light.

Uh. The *camera* meters for ambient light, of course. And uses the flash to fill in the foreground.

-- NK Guy (tela@tela.bc.ca), December 28, 2001.