Optical Slave

Is there any optical slave flash out there that will work with a Canon flash -- that is, without being fooled by the pre-flash? Or do I have to turn off the pre-flash when using any kind of optical slave? I want to light up a portrait background and don't want to have to sacrifice one of my 580 EX II's to do it. Any suggestions are appreciated .

No pre-flash in manual mode.

There are digital slaves on the market that say they will ignore the pre-flash. I've not heard any great reports on them working.

As Paul Li said, put it in manual mode.

(I did not consider flash units, just triggers...)

Paul's advice is still good - manual mode, no pre-flash to worry about.

The Yongnuo YN460 ignores the preflash, reliably

Psychobiker wrote in post #8578189
The Yongnuo YN460 ignores the preflash, reliably

my YN460 will trigger from a preflash, (when set on s1 or s2) maybe I'm doing something wrong

That's odd. Take another flash, set the YN460 to S2 and press the test button on the other flash in very quick succession. It should only fire on the second flash

http://www.bhphotovide​o.com …PN_Peanut_Slave​_100_.html

http://www.bhphotovide​o.com …40030D_HS_D_Hot​_Shoe.html

Psychobiker wrote in post #8581894
That's odd. Take another flash, set the YN460 to S2 and press the test button on the other flash in very quick succession. It should only fire on the second flash

I don't have another flash, the popup preflash on a 450D definitely triggers the YN460 with the mode set on s2

I don't own this flash but this ebay listingsuggests that S1 is the pre-flash mode.

YN460 isn't supposed to do that in S2 mode - maybe try contacting YongNuo?

OK - I rest my case.

My XS has preflash in manual mode, I have to use a cheapo flash to trigger slaves. Unless I use S2 which just fools the ETTL and blows out the shot.

I've only had the flash for a few days (still experimenting). I can turn off the preflash in the custom menu and/or shoot in manual mode so the preflash trigger is not a big deal.

watt100 wrote in post #8584252
I've only had the flash for a few days (still experimenting). I can turn off the preflash in the custom menu and/or shoot in manual mode so the preflash trigger is not a big deal.

You cannot turn off the preflash that is used to set exposure on the built in flash on any Canon DSLR.

Enjoy! Lon

FlashZebra wrote in post #8584704
You cannot turn off the preflash that is used to set exposure on the built in flash on any Canon DSLR.

Enjoy! Lon

seems to work on my model, when I set custom function 7 on my 450D "only external flash" emits the preflash does not fire on Tv or Av mode