Fill in flash problems

[redliner]

I just bought a wireless fill in flash unit. It has a sensor on top, it is like a slave, goes off when your camera flash does, to add a 2nd light source. Just tried it, with my sony, and kodak point & shoot cameras. The result.. photos look neither like a flash exposure, or a natural light. Picture is a flat, underexposed image. Any idea what's going on?

[rjseeney]

Most digital cameras fire a preflash to set proper exposure. What is happening, is the slave flash is firing early because of that preflash. The camera then sets the exposure based on the slave flash firing, which fools the camera into thinking there is more light, resulting in an underexposed image. Any optical slave flash must be set to ignore the initial preflash(es). Check your documentation that came with the unit to see how to do that. One way to test that the flash is set up correctly is to take a picture of the flash unit. If you can capture the flash firing, you have the slave flash set correctly.

[redliner]

Thanks for the information, I'll spend a little more time with it, to see if I can get it working right.

[mnosbor]

You can take a pic of the slave flash if it shows bright in the pic then its working if not its not timing right. Try taking the camera off slow sync or red eye and use just an auto flash.

I have a what Sunpak calls a digital flash it comes in a kit and wasnt expensive, I found it at Ritz camera they had it on clearance I tried with my LZ2 which fires a zillion preflashes to get the exposure and it worked great with it, I have no idea how it knows which flash to fire on but it does. If your unit dosnt work out you might look for the Sunpak unit.

[geriatric]

Thats the trouble with P & S cameras, you have no control. Get yourself a good camera that gives you modes , M P AV TV . You will learn a lot more about photography.