I would like to use a wireless/remote slave for an extra flash. I'm wondering if the E-TTL preflash will mess up the flash synchronization, or timing. Thanx for your help.

-- Darrell Ohs (darelohs@islandnet.com), March 01, 2000

Answers

I use two Ikelite Lite-Link TTL slaves with and Elan IIe and three Speedlites. I used to use them with the 380EX but sold it for a 420EZ to get more power, manual control and longer than 90 sec. (5 min.) auto off (this is the main reason the 420 is better than the 430, and the 540 is even better since it has a "never off" switch for this). The Lite-Links seemed to keep up with the preflash (the slaves would pulse with the 380EX), but I never trusted it. The few trial exposures seemd ok with very broad latitude print film though. The Lite-Links will even keep up with the 540EZ strobing at 100Hz.

But it's easy to defeat the E-TTL if you use Canon's TTL cord set to fire the trigger flash (or just the adapter part). Or you can do it the easy way and just use the built-in flash to trigger the slaves, since it's not E-TTL. If you don't want the built-in flash to show, just put a card in front of it to direct the flash up. It's amazing how sensitive these things are, and they always detect when the first (trigger) flash quenches no matter how much extra light is flashing around the room.

-- Jim Strutz (jimstrutz@juno.com), March 01, 2000.

I forgot to add that if you use a standard (non-TTL) slave the E-TTL pre-flash will definitely trip your slave. This will give your TTL metering false readings, and also dump all the power in your slave units just before they are needed. So you have to defeat E-TTL with a different flash to do the triggering or use the Canon's TTL cord set adapter or use the built-in flash to do the triggering. You could also try using FEL to do the pre-fire about 10 seconds before the real shot.

In any case, you don't want to mix TTL metering (E-TTL or otherwise) with auto or manual flash units. At least not without a flash meter to check yourself.

-- Jim Strutz (jimstrutz@juno.com), March 01, 2000.

Jim's answers are a lot more detailed than what I'll say, so maybe they are worth more. Anyway, it depends. I have a cheap slave flash from Ritz with a built in slave. It isn't sensitive enough to be tripped by the preflash, but it isn't very powerful either. If you don't need much, it may be an option, and it only costs about $20. When I hook a Wein Peanut up to my Vivitar 285HV, it is sensitive enough to trip with the preflash, even outdoors. This of course results in the slave being useless. If you have someone to help you, you can have them turn off the slave once it charges, hit the FE Lock button, turn the slave back on, and then take the picture. That is about the only option I know for using E-TTL with a standard slave.

-- Brad Hutcheson (bhutcheson@iname.com), March 01, 2000.