On 13/1/02 1:18 am, "Ralf Schmode" <[EMAIL PROTECTED]> wrote:
> [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. Anyone using Epson 2450 Photo, Mac + Vuescan? I'm having a problem getting Vuescan to see the device. Thanks Richard ---------------------------------------------------------------------------------------- Unsubscribe by mail to [EMAIL PROTECTED], with 'unsubscribe filmscanners' or 'unsubscribe filmscanners_digest' (as appropriate) in the message title or body
