[EMAIL PROTECTED] schrieb: > I've just got an Elite II and have been checking the deep shadows for > issues, particularly the red channel banding. I have noticed something > very odd. A straight scan (with or without ICE) shows red channel > banding identical to what Ralf got along with some "telephone wires". > However, when GEM is enabled, the banding pretty well disappears. > And it also looks like some of the the other CCD anomalies like the > "telephone wires" also improve or disappear.
Hi again, with my defective Elite II I used GEM once at the default value of 50. I hadn't noticed the banding then, so I can't tell whether it was present or not, but at the value of 50 I noticed *huge* "averaging" of the colors, just a bit like Gaussian blur would cause it. That softening effect may well have evened out the banding. > This seems to suggest that the banding (or lack of it with GEM) is not > caused by any change in scanning speed (or anything else mechanical) > but by a glitch in the calibration, which doesn't occur with GEM. Or > alternatively, the algorithms in GEM are just good at cleaning up these > sort of deep shadow problems...... You may find out by using GEM at a very low value (1 instead of the default 50). If it is the cleaning effect of GEM, a value of 1 should leave more of the banding than a value of 50. If it is just a matter of the calibration data being re-written, the banding should be gone even at a value of 1 (which I doubt will remove any grain at all). > I suspect the issue is faulty calibration by the software (maybe made > worse by poor QC) rather than it being purely hardware. Could well be > good hardware let down by buggy software or firmware. I may be mistaken but as far as I know *every* CCD unit would be "faulty" in the sense of showing off "telephone wires" without prior calibration. What I am not sure of is, for example, if a single CCD pixel lost "efficiency" in the sense of electrical response to light exposition (as a result of aging, dirt, you name it), whether or not the Minolta Software would be able to correct this properly. > I haven't reached any conclusions yet whether what I've seen will > constitute real problems in normal scans. Certainly, using GEM and x4 > multiscanning on one of my (underexposed) slides I use as a test and > pulling up the shadows, the result was far better than my old Elite. If GEM, at a low setting that does not affect the overall appearance of a picture, would be able to completely remedy the banding/"telephone wire" issue, this might be a way out. I'll hopefully be able to try for myself next week. If the price for getting rid of the banding is having the image dramatically softened due to a high GEM setting, there will be another Elite II on its way back to Minolta, and a Nikon LS-40 will take its place :-)) > Incidentally, it doesn't look like the current support for the scanner in > the latest version of Vuescan incorporates calibration routines. Pity > really, as this would help clarify whether the hardware or the Minolta > software is the issue. But it would be interesting if the banding issue exists at all with Vuescan. If Vuescan has the functionality of getting at least a raw scan out of the Elite II, I'd be most interested in the results regarding the problems discussed. So long - Ralf -- My animal photo page on the WWW: http://schmode.net Find my PGP keys (RSA and DSS/DH) on PGP key servers (use "TrustCenter" certified keys only) ---------------------------------------------------------------------------------------- Unsubscribe by mail to [EMAIL PROTECTED], with 'unsubscribe filmscanners' or 'unsubscribe filmscanners_digest' (as appropriate) in the message title or body
