Ian,
https://photography-on-the.net …howthread.php?t=2338#9903
Following up on this topic, I've been looking at your post combining the different channel mixers. I'd like to understand the arithmetic steps in combining the CM matrix. I do follow your logic, but my A-level (senior high 
) maths is _waay_ too rusty. Can you please post an idiot's guide (or mail me roger_cavanagh@lycos.co.uk
) on the calculations to combine 2 CMs?
TIA,
