Was: epson 2450 chews now: red line

[Arthur Entlich <artistic-1@xxxxxxx>]

I first will mention that I seem to be hearing more and more cases of 
intermittent streaks, stripes, lines etc, with scanners, both film and 
flatbed, and for some odd reason pink or red is the color of "choice".  Odd.

Second, if you can send me (in private mail) a small sample of a the 
scan like a one inch wide area across the whole scan as shown below, I 
can evaluate it better:

|<edge of scan>-<normal area>-<red area>-<normal Area>-<edge of scan>|

Without seeing the sample, I'm willing to speculate, but that's all it is.

The fact that is is a soft edged defect and that it is more than one 
pixel wide means it is unlikely to be a failure of the CCD.

However, if is red when looking at a positive scan regardless of if you 
are scanning slides or negs then I'm somewhat confused, unless you are 
indicating the red streak shows up in the neg scan BEFORE it is inverted 
to a positive.

The next thing is if there is any information in this red streak, or if 
it is a pure red and with no other information (both color and luma 
levels are constant throughout the red streak) or if the area is just 
redder than the rest of the scan but there is variation in the area 
(changes of color levels and luma levels).

If the later is the case, then one of two things could be happening, 
that I can think of.  I would look at the scan with something like 
Photoshop, which has channel separation, and look at each channel (Red, 
Green and Blue) and determine is the problem is that the Red channel is 
amplifying the Reds in that area, or if the Green and or Blue channels 
seem to be diminished.

If the Red is amplified, then likely something is wrong with the manner 
in which that area of CCD sensors are being calibrated before the scan.

That may mean a damaged or dirty calibration strip, causing the scanner 
to bright  the sensitivity up on those sensors.

If the green and or blue channels are diminished in that area, it is 
more likely that the problem is some dirt on an area that diminishes the 
amount of light getting to those sensors.  Perhaps a piece of dirt that 
is covering the part of the scan bar.  The fact that it is intermittent 
may mean this stuff is moving around.

The next time it happens, you might try placing the scanner on its side 
edge and doing a scan that way.  This may dislodge the dirt and move it 
out of the way.

I'd prefer to see a section of the scan because everything above is 
based on "blind" assumptions.  I probably will have a better idea once I 
can look at it and see which channels are doing what.

Art

Also,


Artistic Photography wrote:

> I would say faded on the edges and more than one pixel wide.  Mike
> 
> Michael and Mary Messner
> Artistic Photography
> www.artistic-photo.com
> 
> 
> 

When using the Epson Expression 1600 scanner for negatives or
 > transparencies we sometimes see a reddish stripe running the length of
 > our scan.  The line seems to come and go.  I have cleaned the glass
 > many times and this doesn't seem to be the problem.  Any ideas?/  Mike
 >
 > Michael and Mary Messner
 > Artistic Photography
 > www.artistic-photo.com


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