Scanmate CQ-Scan
Scanmate CQ-Scan
- Subject: Scanmate CQ-Scan
- From: Josef Fallnhauser <email@hidden>
- Date: Mon, 21 May 2001 09:19:32 +0200
Hi Martin
>
Could you re-cap on the version of CQ that you are using with your scanner?
>
Significant changes have been made recently -- the first versions of CQ 5
>
would not work properly with the updated ICC profiles that were supplied
>
with OS 9.1.
I worked with CQ 4.4.1 and OS 9.1. That might have been the problem. I also
just set up the 30 days try out version CQ 5.1.1 and it seems to be much
better now. Also the button to click on or of "Use Toner Response Curve" is
not available anymore.
>
CQ 4.4.1 and previous versions did not use ColorSync for conversions from
>
RGB to Lab. CQ 5 uses the profiles specified in the ColorSync control panel.
Which profile do you choose as the Lab profile in the ColorSync application?
>
I seem to recall that your main problem was a consistent red cast in
>
Photoshop that did not appear on your monitor in CQ.
>
>
We never get a red cast on tranny or print -- so perhaps your Photoshop
>
colour management is at fault here?
>
>
That is not to say that we never get red casts! CQ still has a bug when
>
using magnetic transparency mounts -- the images are always red when opened
>
in Photoshop. I also believe that there was an additional bug that would
>
cause a red cast if you didn't have virtual memory switched on on a
>
Macintosh.
I never have virtual memory switched on. Normally this causes a problem and
not vice versa .
With the new CQ 5.1.1 version I made a it8 profile internal and external
with ICC Scan. Again, the picture I scan with the internal calibration and
convert - when opening in PS 6 - to my RGB working space, is more red, than
the scan I do with the ICC-Scan generated profile - that is more correct to
the visual comparison with the slide.
>
We suffer the same problems as you when scanning negatives. ........
>
>
The preview problem could be down to CQs internal workings. Normal positive
>
previews are Lab files, while negative previews are RGB files -- why this is
>
I don't know, but I found out by checking the preview files in Photoshop and
>
in BBEdit. When the data is cropped from the preview and inverted with the
>
curves set in the negative developer, the RGB data is then positive and it
>
is converted to Lab with the ColorSync generic RGB profile. They are then
>
treated the rest of the way through CQ as if they were positive images.
>
>
This doesn't seem very efficient to me -- and is the most likely cause of
>
the colour shift between approved screen image and the final data opened in
>
Photoshop.
I have never done negative scanning until now, but this is an interesting
story. Maybe the discussion is going on with this.
Regards,
Josef
-----------------------------------------------------
Josef Fallnhauser (c/o Studio Trizeps)
Zollergasse 13/9
A-1070 Wien / Austria
Tel: +43(1)5263393 Fax: +43(1)5266020
www.trizeps.com
mailto:email@hidden