Need some help please and I will be specific.
Scanning C41 Negatives using my Nikon D600/D800 with a Sigma 105 1:1 macro lens to produce 6 stitched images of 4x5 C41 negative.
Scanning with fluid, AN glass and a sheet of optical mylar, the set up is as follows.
light source, raised AN glass (frosted side up) layer of fluid, negative emulsion side up, fluid, optical mylar.
DSLR shooting through the optical mylar and using live view highly magnified, focusing on the film grain.