A lot less power off camera than on?

Can somebody shed some light on this issue for me?

I have a Quantaray QDC900WA that I have been using on camera for a while and has been doing pretty well. Recently, I wanted to start dabbling in OCF so I've tried a couple of times to trigger the flash off camera with my 60D's wireless function. The issue I run into is that it seems like the QDC900WA loses a LOT of flash power when off camera.

Well in reality, I think the flash output is the same, but it is underexposing a LOT compared to what I would get with my flash being on my hotshoe. I would imagine that with my flash off camera and CLOSER to the subject I'm trying to expose, a correct exposure would require a flash output power that is less than what would be required when the flash is further away on my camera. Because of this issue, I'm really confused about OCF.

Thanks for your time!

I may be wrong on this assessment, but : The Canon Wireless System is a "Coded" IR type of signal, and is not compatible with most aftermarket units. I doubt Quantaray was made to trigger from a Canon System. It probably is made to trigger from Visible Light! Some visible light is probably being emitted by your camera, and triggering your unit a bit late, thus the underexposure.

Do you have a Flash Meter to check output with?

I cannot find much info on your flash. Does it have a Canon slave mode or just a simple optical slave mode? If it is the later, you cannot use the master capability of your camera. A simple optical slave mode will fire too early when it sees the preflashes of your master flash. It will not understand the commands anyway so turn that feature off in your camera. Set the camera popup to manual mode to eliminate the preflash and it should fire in sync.

Edit: I did find a manual for the flash here. http://www.hcfx.com/mi​sc/Quantaray-QDC-900WA.pdf

As I suspected the slave mode is a simple optical trigger that fires when it sees any flash. The master mode of your 60D is useless with this flash. It works against you as you are seeing. The flash is firing when the popup is sending out the command flashes that would be used by a real Canon slave flash. Turn wireless control off and set the popup to manual mode. This way it would sends out the exposure flash and the slave will fire in sync.

I think the Quantaray has only an optical slave mode.

So if I turn off the wireless function and ETTL on the built in flash, the flashes should be syncing correctly, but I will end up getting fill from the popup. Theoretically, if I power down the flash as much as I can, is it possible to reduce the affect of the popup to almost zero?

That is your only option short of using a sync cord or some inexpensive wireless triggers.

Thanks for your help guys. I'll definitely give it a go as soon as I can. I never thought about the flash being incompatible with the Canon wireless function and the OCF had become very confusing and frustrating. I really appreciate all the help this forum gives.

Cheers!