I asked a question last week regarding how best to scan PMK 4x5 negatives - as RGB or Grayscale scans. For those interested I wanted to share the results of my test. I took a sheet of tri-x developed in PMK to my local lab which uses an Agfascan XY-15 flatbed scanner for high-res scanning (8000 element flatbed, Dmax of 4.1 density range of 3.9, and up to 15,000 ppi)). No, its not a drum scanner but I've had numerous 4x5 sheets of velvia scanned on this setup and printed via a LaserLightjet printer and the results are absolutely stunning.

I had 2 scans done, one as an 80mb RGB scan, the other as a Grayscale scan. The results were quite obvious. The shadow areas of the Grayscale file were muddy and lacking in detail, while the same areas of the RGB scan were detailed and maintained very nice contrast. Highlight areas were about equal on both. The differences in the shadow areas were not minor either - they were quite obvious. So, all the remaining scans I have to do will now be scanned as RGB files, then converted to grayscale and burned onto a CD. Converting to Grayscale has no effect on the quality of the RGB scan. The nice part of this is that I get the quality of an RGB scan, but they will only charge me for the files size of the Grayscale scan - which is 1/3 the size of the RGB scan.

I can't comment if this holds true for negs developed in a non-staining developer as all I have are PMK negs, but I will not even consider a true Grayscale scan of anything in the future.

Hope this helps....