White Balance: opinions on this?
 

http://www.expodisc.com

Came across this in another forum. Does anyone have an opinion on this product?

It is the equivalent of the incident light cover for a lightmeter. The rationale for the use of this type of light measurement is that it is used at the point where the subject is, not from the camera postion. And it would be pointed back at the camera position. (were it a light meter).

It was designed for digital still cameras.

I don't see that it can work any better than the traditonal white card placed so that it is illuminated by the light falling on the scene.

Sony used to ship a simple version of this as a lens cover on their Hi8 cameras.

I don't think I'd spend the $50 for it that they ask.

I think it's worthless, and that many people would use it wrong...ie., they would point the camera at the subject and hit the white balance button. To use this properly, you would have to go stand where the subject is and then point the camera back at the light source, as you would with an incident meter. You can buy a lot of sheets of white printer paper for 50 bucks.