Quote Originally Posted by tbm View Post
Richard: Aren't these two comments contradictory?

"The timer clearly has no knowledge of what filtration you're using."
"On a dichro head set max Y when using ch.1 and max M for ch.2."
No. The timer does not know what filters you're using. It's up to you to change the enlarger filtration, there is no information feedback from the enlarger to the timer, nor does the timer itself control the filtration. The usual way to split print is to make two exposures, one through a soft (max Y 0 M) filter and one through a hard (0 Y max M) filter. We suggest you use ch.1 for the soft exposure and ch.2 for the hard in which case in split-grade mode the firmware prompts you when you change channels to set soft or hard filtration appropriately. That's all. The later firmware also computes a notional grade based on the ratio of the two channels and assuming you're using Ilford filters; for dichroic heads this is unlikely to be accurate but it doesn't matter, it's the result on the paper that's important. Changing the soft exposure mostly affects the exposure and is useful for setting the highlight density, changing the hard exposure mostly affects the contrast and is useful for setting the shadow density.