Hi, I am struggling with flashguns and exposure and wonder if anyone can shed any light (pun) on the subject. It's quite a complicated issue, so I'll take it step-by-step. I am not new to photography, but I am very new to flash photography.
Being short of cash due to redundancy, and wishing to try and start a photography business, I bought a cheap flashgun from eBay, Yongnuo Speedlite YN467, and a wireless trigger, Yongnuo RF-602. The trigger can be bought separately and is compatible with Canon equipment. I haven't used either very much, except to try them out, but both have worked very well.
Then, a couple of months ago, my husband became due some pension money from a previous employment, and bought me a new lens and a Canon 580EX II flashgun. So, I figured I would be able to use the wireless trigger with the Canon flash. But there is a weird issue that I am having trouble figuring out.
With the Yongnuo flash, whether I use the flash on-camera, or off-camera using the trigger, the result is the same (not changing any of the settings of either camera or flash, in TTL mode).
With the 580EX, I get a good exposure with the flash on-camera, but when I try it off-camera with the trigger (not changing the settings as above, ETTL mode) it is a white-out - nothing recognisable in the image, just pure white. To get anything like an acceptable exposure with the off-camera trigger, I have to switch the flash to M mode and turn down the compensation to 1/128 power.
Where am I going wrong? Or is this what should happen?