Well I just tried Melanie's "Easy Contrast" circuit and it works great!
I tried with and without a filter cap and there's no visible difference.
I ended up using 2K and 1K resistors because I had some laying within arms reach and it gives good control.

That's cheaper and uses less real estate than a trimpot, and it gives the user control that I was going to use a digital pot to achieve. With only 2 resistors.

Most Excellent! Thanks Melanie!


steve