Trying to fire 580ex ii remotely from 40d, help please

[78novacaine]

Ok, we are trying to get my friends 580ex ii set up to fire remotely with her 40d, we are thinking she was sold the wrong adapter, she asked for something to allow her to fire it remotely, this is what they gave her, there is no brand name or part number on it, and we are both new to off camera flash, I just bought some cheap radio triggers personally:

[DHaass]

You need a trigger and a receiver to do that. This looks like what you would mount the flash on for remote operation, but you need something to send a signal to it in order to fire the flash when the shutter goes off. The trigger would be mounted in the hot shoe on the camera.

[photosteve]

That’s a real cheap way to do that. That piece goes on the flash and then uses the onboard flash to trigger it. So line of sight and about 10 feet. I would go with triggers there more expensive but the best way to go.



Steve

[DHaass]

Which in this instance means the flash on the receiver needs to be set as slave. The on-camera flash needs to be popped up when they do it.

[camera shy]

That device is an optical slave. The remote flash attaches to it. When any other flash goes off it triggers the optical slave which triggers the remote flash.
They work very well, but are quite limited and everything is manually adjusted.
The wireless triggers work exactly the same except they don't trigger optically, but trigger via radio.

Put up your built in flash, point the camera at the optical trigger with the remote flash attached and turned on Manual.

[78novacaine]

Ok, thanks for the tips! We were not sure since there was no part number or brand name anywhere on it to look it up and see how to use it :lol: She is probably ordering a set of cowboystudio radio triggers to match mine since we were on a shoot yesterday and she loved the flexibility my setup gave me, in fact she is borrowing them for a shoot today, haha.

[ngoduyviet]

It's an optical trigger like everyone else said.

Mount your 580EX II flash on top of it, set your flash to manual setting power to what you need, then push on that little button with the flash icon on your camera to pop up your on-camera flash and shoot away. Does not work well if you are too far from your 580EX II or under bright sunlight.

Cheap & great way to learn for beginners, play with it till you are comfortable and upgrade to radio triggers later.

[78novacaine]

I already have radio triggers for my setup and love them, just need more receivers and more flashes now! Haha, I was posting this for a friend of mine, and I informed her of what ya'll have said.

[picman]

The built-in flash on the 40d is e-ttl that can't be set to manual. It fires a preflash to determine the exposure just before the main flash (happens so fast that's it hard to see it happen) The bad news is that the preflash will trigger your optical slave.
Here's a clunky work around: EOS Documentation Project - Loke: Blank FEL - How to sync studio strobes with an E-TTL-only camera

There also is a possible issue with Canon flashes. I haven't looked into it much - Google
Canon flash Reverse Polarity. They seem to work better with a pc cord hook-up instead of hot shoe.

If you want to experiment on a budget, toss the optical trigger and get a set of Cactus triggers.

[JohnT]

If just one flash is all she wants to fire, an extra-long E-TTL cord will work in a lot situations, and it's cheap compared to radio triggers.

ETTL Cord for Canon Speedlites | Off-Camera Flash Cord | OCF Gear

I am not affiliated with the above link or do I get a kickback. Just fyi.

[ngoduyviet]

Originally Posted by 78novacaine

I already have radio triggers for my setup and love them, just need more receivers and more flashes now! Haha, I was posting this for a friend of mine, and I informed her of what ya'll have said.

So you know how to trigger with radio but not optical? very interesting. No pun intended, as I learned to do basic trigger first before moving up to radio then radio-ttl.

[78novacaine]

Originally Posted by ngoduyviet

So you know how to trigger with radio but not optical? very interesting. No pun intended, as I learned to do basic trigger first before moving up to radio then radio-ttl.

The first time I ever used off camera lighting was when I spent last summer working with a guy I know shooting drag racing using pocket wizards and metz flashes, I guess I saw no point in trying anything else when I already knew what worked best

[ngoduyviet]

Originally Posted by 78novacaine

The first time I ever used off camera lighting was when I spent last summer working with a guy I know shooting drag racing using pocket wizards and metz flashes, I guess I saw no point in trying anything else when I already knew what worked best

if it works, it works :)

[Village Idiot]

It is possible to use the 40D with an optical slave and the pop up. The exposure lock button will cause a preflash and then pressing the shutter button will cause the actual flash. This isn't an ideal way to work, but it does.

Also, but screw lock PC cables for the 580EX II if you're not using a shoe trigger. Regular PC cables are unreliable at best.