Is there ANY mode for either the flash or camera (EOS 3) that will eliminate the pre-flash? It's driving me crazy.

Here's what I'm doing. Maybe some of you can offer suggestions or alternatives.... I have two 550EX's and the ST-E2. I mainly shoot portraits in a studio environment. My main and fill lights are monolights and I use the 550EX's for the hair and background lights (not always both at the same time). Both the camera and flash are used in manual mode. The ST-E2 triggers the 550EX's which in turn trigger the slaves on the monolights.

Because of the pre-flash I've had to reduce the sensitivity of the slave sensors on the monolights enough so that they ignore the pre-flash but fire at the main burst. This causes its own problems in that it's possible to position a flash in such a way that it won't trigger the main lights. Look Ma, a blank neg!

If it's impossible to kill the pre-flash, I'm thinking of buying a couple of slaves to attach to the 550EX's to totally disconnect them from the camera. I'd then use either a PC cord to one of the monolights (dangerous!) or buy a different wireless xmitter/receiver.

These lights are almost perfect for me for these purposes, plus I already have them. I just need to figure out the best way to use them.

Paul

-- Paul Ferrara (paul@columbusoft.com), September 21, 2001

Answers

The 550EX has several custom functions, one of which (#3) turns off E- TTL along with it's pre-flash. I'm not sure how that will effect the wireless mode though. In addition, the ST-E2 may continue to use its near IR preflash to set the 550EX's up for slave use, and that may prematurely trigger the monolights too, so this may not work.

Most optical slaves give Canon Speedlites fits, often causing them to lock up after the first firing. Some people have reported success by insulating all but the center pin of the flash foot. I use the Ikelite Lite-Link TTL slave to fire my 550EX in manual mode. It always works and is very sensitive.

-- Jim Strutz (j.strutz@gci.net), September 21, 2001.

Duh! RTFM, huh? I didn't even realize the flash had custom functions but even if I had, I doubt if I'd have associated that one with the pre-flash so THANKS A MILLION. Your solution works great. Flawlessly, in fact! Removing the ND filter (6 stops worth) from the slave sensor on the monolight appears to cause it to fire no matter how the 550EX is aimed and given the position of the monolights relative to the camera the IR from the ST-E2 won't be a problem although I realize this could crop up down the road.

Jim, thanks again.

Paul

-- Paul Ferrara (paul@columbusoft.com), September 21, 2001.