Looking to try OCF, question though.

I'm wanting to try OCF badly but the flash I have right now has no pc port for a wireless trigger (Promaster 7500). It can be optically triggered by another flash though. Now does this mean that another flash unit must go off (i.e. fire) for it to go off as well or can the other flash unit just control it, like a remote control (infrared I assume). I found a new 430 EXII on ebay for a good price, but I like the fact that the 550EX or 580EX can be a master to another other Canon flash. Any suggestions?

Nathan

Yes, another flash must fire to set off the optically triggered flash.

Yes the 580 can be a master to another Canon flash, but then that would mean you'd have to buy another Canon flash. You can look into remote trigger/receiver combos to fire your existing promaster (pocket wizards, skyports, hell even CTR-301P's or Cactus V4's if you're on a really tight budget).

With the your Promaster 7500 in optical slave mode, any manual flash can be used as the master. This would include any Canon Speedlite with a manual mode (including a 430EX), or even the budget-priced automatic flash units by Sunpak, Vivitar and others. Those traditional automatic flash units can be used as master, even in auto mode. A flash in E-TTL mode can't be used as a master because the pre-flash will trigger the slave prematurely.

Note that the Promaster 7500DX will not work when attached to a generic hotshoe adapter, so forget the various radio trigger systems. The only way to use that unit off-camera is with its built-in optical slave.

Well that's a bummer, my wife bought me the flash. I could still just get a 550 or 580 and use a wireless trigger with one of those.

There's one thing you can do without spending a dime.

Use the Promaster off-camera in slave mode. Pop up your camera's built-in flash. Set your FEC to -2 and it won't contribute to the exposure. Hit the * button to fire the preflash, wait a few seconds for the slave to recycle, then take your shot.

Probably not a practical approach if you're shooting that adorable child in your Flickr stream.

Ok, I ordered a 580EXII and the Gadget Infinity soft box combo with triggers. Now I know I will not be able to utilize the ETTL using these triggers, here is my question, if I bought another Canon flash, probably 430EXII, will the 580 be able to master it and still use the ETTL function?

Nates98cbr wrote in post #8531709
if I bought another Canon flash, probably 430EXII, will the 580 be able to master it and still use the ETTL function?

Yes, but only if the 580EX II is on the hotshoe or connected to the hotshoe with an Off Camera Shoe Cord that provides full communication with the camera (disregarding the expensive radio-based E-TTL triggers out there).

Take this one step at a time. The 580EX II can be fired off-camera with the radio triggers in manual mode. Your Promaster can be used in slave mode for a second off-camera light.

Once you get accustomed to manual flash, you may realize E-TTL isn't all that necessary for off-camera setups. Honestly, a flash meter would be a wise next investment, rather than another Speedlite.

Curtis N wrote in post #8531871
Yes, but only if the 580EX II is on the hotshoe or connected to the hotshoe with an Off Camera Shoe Cord that provides full communication with the camera (disregarding the expensive radio-based E-TTL triggers out there).

Take this one step at a time. The 580EX II can be fired off-camera with the radio triggers in manual mode. Your Promaster can be used in slave mode for a second off-camera light.

Once you get accustomed to manual flash, you may realize E-TTL isn't all that necessary for off-camera setups. Honestly, a flash meter would be a wise next investment, rather than another Speedlite.

Yea, I was reading through another thread and realized I've already spent too much money and I can and need to learn to set them up manually. The soft box kit I ordered comes with the Cactus V4's.