Leafscan45 stitching

Discussion in 'Scanning and Scanners' started by alanrockwood, Jul 27, 2018.

  1. alanrockwood

    alanrockwood Member

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    A question about using stitching with a Leafscan 45 scanner: (Yes, I know it's an ancient scanner.) I see that some people scan MF film at ~5000dpi in two or more sections and them stitch them in Photoshop to recover the full image at high resolution. I also see that people scan 4x5 film at ~2500 dpi in two or more sections and them stitch them to get a 2500 dpi scan of 4x5 film. I think this works best with the glass or sapphire wet mount gizzmo. Is it possible to scan 4x5 at ~5000 dpi in multiple sections and them stitch them to get a 5000 dpi large format scan?
     
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    OP
    alanrockwood

    alanrockwood Member

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    I think I know how one might accomplish the same thing as what I am asking, but using an indirect method.

    The idea would be to scan the 4x5" film or transparency in three overlapping groups of scans at ~2500 dpi. Each pieces would be scanneded several times with a miniscule random shift between the scans within each of the three groups. One would then use a superresolution program, such as PhotoAcute3 to the scans within a group. The result will be three enhanced resolution (~5000 dpi) scans. These three would then be stitched to make the full high resolution scan (~5000 dpi).

    A fly in the ointment is that PhotoAcute3 has not been sold for several years. One can still download the program, but it is an evaluation copy that puts a watermark on the image when it is saved. Another thing is that leafscan is a very slow scanner, so by the time one does all of the scans a long time will have elapsed.

    By the way, yesterday I tried PhotoAcute3 on 8 repeated scans made with a canon FS4000us scanner, and there was a very noticeable improvement in resolution of the image. This was most obvious in random lint fibers on the negative, which were much sharper after the superresolution process was applied. This was not a result of conventional sharpening, but comes from the fact that if you scan the same image several times with very small random shifts in the image for each scan it is possible to synthesize a resolution enhanced image... that's true resolution, not just sharpening.
     
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