Re: evaluating identical media in incorrect lighting conditions
Re: evaluating identical media in incorrect lighting conditions
- Subject: Re: evaluating identical media in incorrect lighting conditions
- From: Barry Gorrell <email@hidden>
- Date: Wed, 28 Jan 2004 09:55:08 -0500
Hello John & Steven,
I'd have to agree with your assessment of the John's problem. Unlike most
Non-RIP driven inkjet printers the output from a Lightjet can vary significantly
with the chemical processing on which it depends. In fact it's one of the few
RGB devices that requires careful "linearization" prior to profiling and at
least daily rechecking of the linearization target afterwards.
Barry Gorrell
Image Techniques
___________________________________
On Tue, 27 Jan 2004 20:28:36 -0800
CitizenRay <email@hidden> in response to
John MacDonald wrote:
>
What you describe may be, and I think likely, the result from a
>
problem in the bleach-fix. Leuco-cyan dye is a colorless
>
form of the cyan dye caused by poor bleach-fix performance.
>
Prints with leuco-cyan dye will appear to have a reddish cast
>
in the higher neutral-density regions of the images.
>
The most common cause of a leuco-cyan dye condition is
>
low bleach-fix pH. This can result from overreplenishment
>
of the bleach-fix tank or from incorrect pH.
>
>
Refer to the document at Kodak.com: Process Monitoring and Troubleshooting
>
with KODAK PROFESSIONAL Pro Strips Color Negative Paper Control Strips / for
>
Process RA-4
>
>
Viewing conditions make a big difference to this phenomenon as does time.
>
Both of which you've encountered.
>
>
It's not your imagination. Scan your sample print using a flat bed scanner
>
and compare that scan against a Kodak IT-8 paper target using the same
>
scanner at the same time. The scanned results should show much more red in
>
the suspect print paper.
>
>
Hope this helps,
>
>
-Stephen Ray
>
>
> We printed some files on a Lightjet last week. We made new prints from
>
> the same files this week. Some of these new prints were 200 percent
>
> enlargements, some had slight color corrections made to them, and some
>
> were unchanged from the first.
>
>
>
> When I viewed them in unbalanced light, the new ones all looked
>
> significantly redder, far enough that it would be unacceptable to the
>
> client. When I viewed them in balanced light, the new ones only looked
>
> slightly redder and were acceptable. So while the new ones did not
>
> exactly match under either light, they were acceptable under a balanced
>
> light source and unacceptable under an unbalanced light source.
>
>
>
> I am hoping someone can confirm that this is possible and not just my
>
> imagination.
>
>
>
> Thanks!
>
> John
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