After experimenting and fudging around I have formed a hypothesis and a few ideas. I did an experiment of developing some C41 film in xtol, (used an offcut thats been directly exposed to light) and cut that up into pieces, that nor undeveloped c41 doesnt appear to clear in tetenal superfix odourless (my b&w fixer - acetic acid + sodium metabisulphate), but clears in its own fix (thiosulphate) - as does developed b&w, the developed film clears but stays dark, the undeveloped clears Where as the bleach completely clears both developed (using xtol) and undeveloped C41 indentically. Which leads me to the fact that b&w developer only affects the silver, doesn't mess with the dye (hopefully). This gives me a hypothesis - and sneaky idea of developing correctly BW400CN in C41 dev, then developing in another bath of xtol - which hopefully should only affect the silver and not the dye, and doing a bleach bypass and fixing only in thiosulphate. Thereby theoretically increasing the contrast range captured, effectively increasing the exposure latitude. Hopefully it wont turned into a big mess though.. thought of trying it on colour C41 too.. but -if- it works, i think it might give an overall desaturation - not a deal breaker as can be increased in digital darkroom if needed, and the monochromatic image on the silver may have a different tonal range which may increase subtleties - esp on intense films like kodak ektar 100 - but pushing the monochromatic image past the colour image i think would give monochromatic deep shadows where the dyes had clipped. I think that it may give some interesting images however. Has anyone tried this before? What results did you get?