I need to remotely fire an EX flash unit. I can't use an ST-E2, due to certain issues I can't go into. I also can't use PW's, again, client issues. I need to be able to to place it in a remote hot shoe and fire it with a long PC cord. On researching the issue, it seems sometimes the EX series locks up after one flash, or in some cases doesn't work at all.
Any suggestions, or perhaps you have a certain brand of remote shoe that works. Any help would be appreciated.
A Vivitar 253 or 285 would certainly work. If you've got a flash on the camera, and if you're the only one using flash you can trigger it with an optical slave, provided your flash on camera doesn't send out a pre-flash.
What happens is that the EX goes to sleep after 90 sec. To prevent that do the following:
Set wireless switch / menu to "SLAVE"
Press mode button for 2 sec. until the "M" on the LCD begins to blink
That causes the 580ex / 430ex to act like a manual flash, firing per the signal on the center pin of a generic hot shoe. That instruction is actually in the 580ex manual on p. 43, but not in a way which is readily understood.
As an alternate to a very long cord what I've done on occasion is hidden the flash, using a Peanut slave on the end of a 15' PC cord I have, place somewhere out of frame it could see the light from the "master" trigger flash.
Chuck
Edited by cgardner on Jul 26, 2008 at 12:16 AM GMT
A poorly made hot shoe adapter can lock up your flash (shorting of pins of the flash). Get a quality hot shoe adapter and a snug fitting pc cord-paramount or make yourself one.
There are no IR emissions involved in the EX system!
The 580ex and 580exII emit the control signals with visible light from the main flash head. They occur during before the shutter opens and are the brief burst of flash you will see in the viewfinder before the mirror blocks it and the shutter opens.
The ST-E2 master controller is not IR either. It consists of a regular flash tube with a deep red filter on it which filters it down into the near-IR range, mainly so people will not see it and blink. The rods at the edges of the eyes which are 3000x more sensitive than the color-sensing cones in the center can't see red: they only react to a narrow band of wavelengths in the green/blue part of the spectrum. As a result we don't perceive the deep red of the filtered light as well as the sensor of the slave flash.
The angle of coverage of the flash limited by the spread of the flash zoom. When put into master mode the flash will automatically zoom to 24mm to maximize the signaling foot print. Another myth about Canon is direct line of sight is needed. Bounced light will also work if it is bright. The slave sensor just needs to see the light from the master in sufficient quantity, not have line of sight. I've trigger mine through doorways, etc.
