SB 800's on a Canon

Should have included this in my other post.

I good friend of mine is looking to upgrade all his SB800's to the 900's at one time instead of one by one. He was joking that if they would work on mine he would give me a killer deal. Which made me think... would they work on my 7D? I doubt I would be able to use any of the ETTL stuff. But why woulnd't it work in manual. Even with out me using a PW or popper to fire them. Could I just put it on my camera, set up the others and go?

For some reason he didn't think that the voltage was the same between models and might fry something, or that it wouldn't be able to trigger the other ones even if the one on camera would work.

If he lived closer we would try it to see if it works or not. Since I was looking at picking up a couple speedlights this really caught my interest.

Don't do it. You could damage the flash or your camera.

Basically - the camera send an electrical current to the flash using a specified voltage. Canon and Nikon use different voltages - you could basically fry something.

Off camera, yes. You can use PW or Cactus, or whatever. But not on camera...

Even if he cut you a deal, you'd still be paying a lot of money for something you can't use (iTTL). I'd recommend spending that money on better flashes (Canon 430exII for eTTL or Yongnuo YN560 for manual).

This shouldn't be a problem. The hot shoes are both standard ISO compatible and the x-sync contact on the 7D will fire the SB-800. Maybe only in camera mode "M", though, and not in "P" or the green auto mode. ETTL is not possible with a Nikon flash. Canon has 5 pins in total on the flash foot, Nikon only 4, and arranged in a different pattern.

The flash can be used in manual mode, but is does also have an auto mode where it controls itself. In theory, that should work so that the camera gives only the trigger signal, and the flash controls the output itself. In that case, you have to set ISO and f-stop on the SB-800, and it also does not zoom with the lens or anything.

Trigger voltage is not a risk - my SB-800 has 4V on the flash foot. Correct me if I'm wrong, but Canon EOS DSLR can handle at least 6 volts.

Assuming the price is right, you can use the SB-800 in manual mode on the flash or off. And, believe it or not, it can even be used in conjunction with the 7D's internal flash in E-TTL mode. What this means is that you can extend the range of the built-in flash by augmenting it with the SB-800 flash. E-TTL will take care of of the exposure. Since the internal flash will need to be popped up, the SB-800 won't be able to sit in the hotshoe. However, you can mount it on a flash bracket or on a light stand close by the camera. Just make sure that the SB-800 can see the built-in flash. The SB-800, BTW, needs to be set to SU-4 Auto mode for this to work.

And, of course, the SB-800 can also be used as an optically triggered slave to the 7D's internal flash (in manual mode) by setting the SB-800 to SU-4 Manual mode (you'll need to set the power level yourself).

Point out to him that the SB900 is huge, heavy, and can destroy D700 hotshoes as they're made of a soft metal (but are replaced with something better when they're fixed).

I suspect the SB800 has an auto mode you can use, but I only have SB900s so I can't say for sure. I think you're better off with something Canon compatible though, ideally a Canon flash. I don't think Nikon flashes would damage a Canon camera btw, i've used Nikon and Canon flashes on both Nikon and Canon bodies with no problems.

CiM_Photography wrote in post #12093257
Basically - the camera send an electrical current to the flash using a specified voltage. Canon and Nikon use different voltages - you could basically fry something.

Basically, it's the other way around. The flash applies a voltage to the camera, and the camera shorts between trig pin and ground when the flash should fire.
All modern flashes use similar voltages. You have to go back to the 80's or so to find units with significant deviations.

I have also tried a Nikon flash (SB-900) on my 7D. Works fine as long as you set the flash to manual power. The camera can be in whatever mode you like.

Great answers.. thanks all.. I'll be taking a drive to his area end of April to play around with them, if he doesn't decide to sell them elsewhere for more cash