My Autochrome project has temporarily turned to the creation of a color scree-plate process with a prescisely ruled screen. I have made a screen digitally consisting of vertical Red Green and Blue lines. When printed in my photo printer ( on an unexposed, fixed peice of sheet film ), the screen is clear and the lines are sharp. When held up to the light, it has an overall grey shade, though it is ever so slightly green. I have not yet tried this photographically, but I did print an image consiting of blocks of color (made with photoshop as if it was taken "through the screen"). It is therefore what a reversal-processed sheet would look like after it has been exposed. When it is held up behind the screen - plate and registered properly (which is quite a trick, even though the screen is regular), the original colors appear; they are dark, but DEFINETELY visible. When I have time to reversal process some sheets of film, I'll try it with this mask. Placing the screen mask over my meter (both handheld and TTL in my SLR), says that the screen cuts the light down by about two stops, maybe a little more. This is not as bad as I thought it would be, especially considering that hte Fortepan 200 sheet film that i have has at least a stop of exposure latitude before processing needs any adjustment. I'll report back when I get this working even better, and I'll TRY to post some examples. I'll probably have to photograph them on a lightbox or projected with a (gasp) digit@l camera, as I really can't scan them, and it takes too long to have color film processed.