The yellow-tape OC-type filters are in the base, and the red-tape red-ortho filters are in the openable flaps. I keep the flaps closed, filtering the light through both filters, and still the light is too bright. So I add cardboard flaps covering about half the openable flaps. With both filters, you should be able to use it for both regular paper and ortho. It is very bright, and you can not turn it on and off with a timer, because it needs to warm up. I sometimes wonder why I got mine, too.

Eric Summerfield

Thank you, that's the most clear explaination and I really didn't know how to use it until now. Thank you Eric!