[filmscanners] Anyone using Epson 2450 Photo, Mac + Vuescan?

["" <soho@eircom.net>]

On 13/1/02 1:18 am, "Ralf Schmode" <rschmode@gmx.net> wrote:

> al@greenspace.freeserve.co.uk 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


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