I was wondering when you should use fresnel in the color channel and whe to use it in the reflection channel?

Thanks,
Steve

Just guessing, that lighting might be a factor, here.

Any more advice on using fresnel?

I'm sorry still a rookie here, I'm  sure Anders or one of the other elder statesmen will be by soon.
Seems like an easy answer, but I don't render in C4D.
Oh Becco:))))

It depends on what you're trying to make. You can use the Fresnel in the Luminance channel to create some great effects, too. Take a few spheres, create a shader, duplicate the shader, and move the fresnel effect to different channels in each, apply one to each of the spheres and hit Render.  That's the easiest way to see the differences.

Yes, Fresnel has an abundance of uses, and channel choices depending on what you want to achieve! - any particular things in mind?

Adam

Aluminum and wood, walnut with a small amount of varnish or clear coat. I know that the aluminum wood have it but I am no sure about a wood finish?

For varnished wood, I'd use in the reflection channel yes.