With the 550ex, we can switch from E-TTL to straight TTL via a custom function on the flash unit. Are there any CF available on the 420ex, and is the ability to switch from E-TTL to TTL one of them? Sometimes I would like to disable the preflash of E-TTL, and I'd like to be able to do this without having to remove the flash and inserting a hot shoe adapter between the flash and hotshoe.

-- David Bindle (david.bindle@usask.ca), December 04, 2000

Answers

Related question if you don't mind... I had overlooked the ability to change from E-TTL to TTL and the preflash has been giving me fits with a couple of optical slaves. I just set CF-3 to 1 and wireless operation still works but I haven't tried ratio control yet. Does anyone have a feel for whether it'll still work or not? I'm guessing not, but...

The manual says... "With a Type-A camera, the CF-3-1 setting will not enable wireless operation with autoflash."

Huh?

Do you think that means that my flash fired at full power rather than calculating the TTL flash exposure?

Paul

-- Paul Ferrara (paul@columbusoft.com), December 07, 2000.

Paul... What camera and what flash(es) are you using? (Canon's wireless) ratio control will only work with... With EOS-3, 1v, Elan 7 and...

ST-E2 and 420ex's and/or 550ex's or... 550ex and other 550ex's and/or 420ex's

I'm assuming you are using a 550ex?? If you are not using other 550ex's or 420ex's as your slaves you will not achieve ratio control by the ratio control on the speedlite units. You won't even achieve TTL (unless you are using something like an Ikelite wireless TTL controller) If you are using all 550's or 420's... I believe the preflash is necessary to calculate the ratio balances, so if you disable the preflash, the ratio controls will not work. What camera are you using and what are you using for slaves? David Bindle

-- David Bindle (david.bindle@usask.ca), December 08, 2000.

Guess I should have included that info. I'm using an EOS 3, 2 550EX's and the ST-E2.

That's sort of what I figured about the pre-flash but thought it couldn't hurt to get other opinions. I've sort of got the slave issue worked out by using a Wratten ND filter over the slave light cell.

Paul

-- Paul Ferrara (paul@columbusoft.com), December 09, 2000.