Although I agree that hardware sharpening, or even non-disclosed software sharpening, is problematic in testing for non-sharpened images in analyzing sharpness, I question the value of looking at a non-sharpened image in terms of determining which scanner has higher resolution, unless there is an absolute way to determine that all sharpening has been removed and you are seeing the "raw" CCD result after just A/D conversion has occurred.
Since each scanner may use different hardware filtering, which is built into the processing, and may not be fully removable, perhaps a better test of a scanner is to simply attempt to produce the BEST scan possible even if that requires using after scan secondary unsharp masking. I mean, at the end of the day (and I do realize the need for an unsharpened image for submission before final correction or use of the image is determined) the idea should be to have a result that provides the sharpest image without adding distracting artifacts from the sharpening process. For instance, if a scanner used hardware or firmware sharpening, would it be possible to accurately "remove" that via software during or after the scanning process? Can using "negative" sharpness, accurately remove the sharpness created via electronics, to bring the image "back" to its raw (unsharpened) state or is it more like switching a TIF to JPEG and back to TIFF and expecting to end up with the same image one started with? So perhaps the best comparison of scans is to have all the images sharpened to the maximum amount they can handle without objectionable artifacting, using whatever methods and parameters of sharpening is required to do that, and compare those results. Art Moreno Polloni wrote: >>>I think you have done a good conclusion here. If you go back in >>>the mailing >>>list you found what I have been written about film flatness problems . I >>>did last summer a test with my own 3 scanners LS2000. LS4000 and Polaroid >>>35+ against Imacon Photo. >>>None of them could match the Imacon scanner in sharpness and Dmax. >>> > >>How do you know that any of the scanners weren't doing some sharpening >>on their own? I'm asking if you confirmed that they weren't... I would >>specifically suspect the Imacon did some sharpening...I don't know about >> > the > >>others. >> > > I tested a Flextight II last year, and later found out that even with > software sharpening set at 0, there's still a significant amount of > sharpening applied. To turn off software sharpening, a fairly large negative > value has to be entered, something like -100 or -200. > > > > ---------------------------------------------------------------------------------------- Unsubscribe by mail to [EMAIL PROTECTED], with 'unsubscribe filmscanners' or 'unsubscribe filmscanners_digest' (as appropriate) in the message title or body
