Oooohhhh. A combination densitometer. That's a good thing. For all the zonistas out there wanting a transmission densitometer, I think that the reflection type is the thing to have. You want to measure the performance, not the score. (Obscure reference to AA, there.) For many years I had a densichron that could be used both ways and I found it useful. I was able to pick up a Rite Way reflection densitometer to measure my pt/pd prints. Dmax is one measurement, but the key evaluation is the percentage dot gain to check the highlights.