? ScanJet 4C Red Shift Question ?

[Mark & Mary Ann Weiss]

I have two scanners: An HP ScanJet IIc and a ScanJet 4c.

The color rendition on the IIc is fine, but the 4c has a red tint to the
shadow/midtones.

This became really apparent when I scanned a B&W photograph in color
mode--the blacks were reddish, looking like a duotone, instead of a
grayscale image.

I would bet there must be some internal adjustment in the scanner to set the
offset values for each of the color primaries and that the one for Red is
misadjusted, but I cannot find this control, as I don't have a service
manual.

Does anyone know how to calibrate the HP 4c scanjet, or at least where the
adjustments are located?

--
Take care,

Mark & Mary Ann Weiss

VIDEO PRODUCTION . FILM SCANNING . AUDIO RESTORATION
Hear my Kurzweil Creations at: http://www.dv-clips.com/theater.htm
Business sites at:
www.dv-clips.com
www.mwcomms.com
www.adventuresinanimemusic.com
-

[daytripper]

On Tue, 06 Jan 2004 03:31:24 GMT, "Mark & Mary Ann Weiss"

Post by Mark & Mary Ann Weiss
I have two scanners: An HP ScanJet IIc and a ScanJet 4c.
The color rendition on the IIc is fine, but the 4c has a red tint to the
shadow/midtones.
This became really apparent when I scanned a B&W photograph in color
mode--the blacks were reddish, looking like a duotone, instead of a
grayscale image.
I would bet there must be some internal adjustment in the scanner to set the
offset values for each of the color primaries and that the one for Red is
misadjusted, but I cannot find this control, as I don't have a service
manual.
Does anyone know how to calibrate the HP 4c scanjet, or at least where the
adjustments are located?

I have a venerable but functionally perfect 4C.
The "adjustments" would be in the software used to acquire the scan, there are
no other adjustments that I know of - that are user-accessible, at any rate.

I would first suspect the bulb is nearing the end of its life...

/daytripper

[Mark & Mary Ann Weiss]

Post by daytripper

Post by Mark & Mary Ann Weiss
I would bet there must be some internal adjustment in the scanner to set the
offset values for each of the color primaries and that the one for Red is
misadjusted, but I cannot find this control, as I don't have a service
manual.
Does anyone know how to calibrate the HP 4c scanjet, or at least where the
adjustments are located?

I have a venerable but functionally perfect 4C.
The "adjustments" would be in the software used to acquire the scan, there are
no other adjustments that I know of - that are user-accessible, at any rate.
I would first suspect the bulb is nearing the end of its life...
/daytripper

I know that the kind of control I'm searching for is not in the software, as
this is more of a service/adjustment issue.
It's been like this since day one, and the bulb color temperature still
looks the same as it always did.
The midranges and hilights are fine--it's only the shadow/quartertones that
have a red tint, leading me to suspect that some gamma adjustment was done
incorrectly at the factory.
Chances are the adjustments might be done through HP proprietary calibration
software, which would explain the lack of physical pots to adjust inside the
scanner.
I've cleaned the glass both inside and out, having disassembled it, and I've
cleaned the bulb assembly as well. Noe of these things made any difference.
If the bulb were red-shifting as it ages, perhaps... but this color issue
has always been there.
I've also used the IIC a lot more than the 4c, so I find it hard to believe
it's a wear issue.


--
Take care,

Mark & Mary Ann Weiss

VIDEO PRODUCTION . FILM SCANNING . AUDIO RESTORATION
Hear my Kurzweil Creations at: http://www.dv-clips.com/theater.htm
Business sites at:
www.dv-clips.com
www.mwcomms.com
www.adventuresinanimemusic.com
-

[Mac McDougald]

Post by Mark & Mary Ann Weiss

Post by daytripper

Post by Mark & Mary Ann Weiss
I would bet there must be some internal adjustment in the scanner to set

the

Post by daytripper

Post by Mark & Mary Ann Weiss
offset values for each of the color primaries and that the one for Red is
misadjusted, but I cannot find this control, as I don't have a service
manual.
Does anyone know how to calibrate the HP 4c scanjet, or at least where

the

Post by daytripper

Post by Mark & Mary Ann Weiss
adjustments are located?

I have a venerable but functionally perfect 4C.
The "adjustments" would be in the software used to acquire the scan, there

are

Post by daytripper
no other adjustments that I know of - that are user-accessible, at any

rate.

Post by daytripper
I would first suspect the bulb is nearing the end of its life...
/daytripper

I know that the kind of control I'm searching for is not in the software, as
this is more of a service/adjustment issue.
It's been like this since day one, and the bulb color temperature still
looks the same as it always did.
The midranges and hilights are fine--it's only the shadow/quartertones that
have a red tint, leading me to suspect that some gamma adjustment was done
incorrectly at the factory.
Chances are the adjustments might be done through HP proprietary calibration
software, which would explain the lack of physical pots to adjust inside the
scanner.
I've cleaned the glass both inside and out, having disassembled it, and I've
cleaned the bulb assembly as well. Noe of these things made any difference.
If the bulb were red-shifting as it ages, perhaps... but this color issue
has always been there.
I've also used the IIC a lot more than the 4c, so I find it hard to believe
it's a wear issue.
--
Take care,
Mark & Mary Ann Weiss

Well there *is* a color adjustment tool in the DeskScan software
interface. But you'd have to tweak it each time DS is started.
VueScan lets you save settings however.

[Mark & Mary Ann Weiss]

Post by Mac McDougald
Well there *is* a color adjustment tool in the DeskScan software
interface. But you'd have to tweak it each time DS is started.
VueScan lets you save settings however.
--
Mac McDougald
Doogle Digital - www.doogle.com

I played with that til the cows came home and all it did was allow me to
change the red tint to another hue, but not get rid of it and neutralize the
quartertones to match my IIc scanner's neutral output.

I'd rather fix this scanner than replace it with one of the new 'toy'
scanners on the market today... if that's possible.


--
Take care,

Mark & Mary Ann Weiss

VIDEO PRODUCTION . FILM SCANNING . AUDIO RESTORATION
Hear my Kurzweil Creations at: http://www.dv-clips.com/theater.htm
Business sites at:
www.dv-clips.com
www.mwcomms.com
www.adventuresinanimemusic.com
-

[Mac McDougald]

Post by Mark & Mary Ann Weiss

Post by Mac McDougald
Well there *is* a color adjustment tool in the DeskScan software
interface. But you'd have to tweak it each time DS is started.
VueScan lets you save settings however.
--
Mac McDougald
Doogle Digital - www.doogle.com

I played with that til the cows came home and all it did was allow me to
change the red tint to another hue, but not get rid of it and neutralize the
quartertones to match my IIc scanner's neutral output.
I'd rather fix this scanner than replace it with one of the new 'toy'
scanners on the market today... if that's possible.
--
Take care,
Mark & Mary Ann Weiss

Try VueScan. It works fine with all the olde HP SCSI scanners. It's known
for it's fine color rendition (and you can save settings if you need to
tweak them).