This is a conceptual exercise, but I want input from experienced color printers. Suppose that instead of building a color pack with CMY filters, or using a dichroic head, I want to print with 3 separate exposures through R G B filters. Suppose I make an automatic shutter mechanism to make the 3 exposure sequence through the different filters for me. Since I am good at electronics, I make myself an enlarger timer to drive my color-exposure-sequencer. I can make the electronics do whatever I want. Now it's a question of what would be the best and most convenient for the printer: The scheme I am imagining, I would conceptualize the R G B exposures in terms of their relative ratio to one another, which I would use for color control. I would have my timer store this ratio of the 3 R G B exposures to each other, and then I could set the total exposure time be whatever I wanted. When I went to print, I would enter my desired exposure time...say, 10 seconds...and if I had set a color balance of 20%/50%/30%, I would automatically get 2s of R, 5s of green, and 3s of blue. If I changed the color balance, the total time would stay the same. Do you think this would be a smart system or would it be better to have the ability to individually increase the exposure time of one color while leaving the other colors' exposure times the same? With the scheme outlined above, increasing the amount of one color would automatically reduce the other colors' exposures to keep the total exposure time the same. Is that what you want when color printing? If I wanted to do something like this, what filters would I use (what specific Lee filter gels or kodak/wratten numbers).