Why is there color crossover in divided C-41?
After mixing the last batch of working solution from my Tetenal kit late last night, and facing having to buy another one when this stuff exhausts, I started thinking (never a good thing...). I had recently started working with Diafine in B&W, and have been impressed with its simplicity and flexibility. So of course, I thought, why not a divided developer? Wouldn't such a developer work for the first developer in C-41? And, as a divided developer, since it works to completion, doesn't that solve any crossover problems?
So some quick research on the web this morning showed me that in fact, this ground has been plowed before, by Patrick Dignan and by this guy: http://nelsonfoto.com/SMF/index.php?topic=9360.0
It seems that in fact, a divided development brew has been done, and it works at room temperature. This immediately sounds awesome to me, and seems a brew I can make myself, which is triple keen, assuming I can find the ingredients.
But then I read replies to Dave Lyga's post on diluted C-41. RPC reported that his sensitometry tests showed crossover in the negatives. Greg Davis showed results with images, but for a different alternative process.
I'm immediately concerned about crossover, because in my experience, it is not simple (or perhaps even possible, practically) to correct it sufficiently to get accurate colors across the spectrum. Tweak one color, you've lost another somewhere else in the image. Frustrating. I don't want it, I'm not a Lomographer.
So, my question is this, specifically for a divided development based process: why would there be crossover, if the developer works to completion in all layers? Wouldn't all the color layers be fully developed, and thus balanced? I am certain this question reveals my full ignorance of what happens in the C-41 process, which is the purpose of the post. Would those deeply knowledgeable about what is going on chemically respond? I would be curious to try a divided development process, but not if in the end I am faced with never ending crossover battles.