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Re: [APML] OT? Markarian's Chain and printing

 On Wed, 14 Apr 2004 16:47:05 +0000, Kevin Wigell writes:
> Paul,
>
> Very nice images. However, this list is for film astrophotography, unless 
> you are discussing processing techniques that are applicable to film as
> well as digital...

 Hey Paul... Kevin...

     Kevin... which part of Paul's printing question is *not* applicable to film ?!? Once an image is digitized, things are much the same... no ?!? 

     I would suggest that Paul's problem is related to the *GAMMA* adjustments of his monitor, in relation to the gamma read out of his printer. You may get this right with a calibration device such as the 'Spyder'... but you can also take another approach.

     Not too long ago, these hardware calibration devices, and their accompanying
software, were in the $1000.00 + range... the realm of professionals and
prosumers. Prices have dropped, and 'entry level' devices are now being produced
as well. Some of the less expensive versions are not true colorimeters, but the
'Spyder' is!

     Even without a 'Spyder', one can come very close to setting optimum system gamma
by following the steps outlined by noted 'amateur' photographer Norman Koren.
This page begins here:

http://www.normankoren.com/makingfineprints1A.html

... farther down the same page, he offers his 'ultimate' test pattern:

http://www.normankoren.com/makingfineprints1A.html#Monitor_test_pattern

     All this info can be very effective, when properly applied. Norman recommends a
free-ware application called QuickGamma... I haven't used this, but I'm sure it
works as he describes.

     The QuickGamma program allows precise gamma adjustments, and most important,
writes these into the video card's look-up table.

     Since most of us have Photoshop, the 'Adobe Gamma' program, part of Photoshop
from v5 on, might be the best choice to make these adjustments visually. (thanks Jerry L. !!!) 

     'Adobe Gamma' does create an ICC profile in addition to the look-up table entry... but it isn't a 'true' monitor profile, like the 'Spyder' generates. You should find
'Adobe Gamma' in the 'Control Panel' dialog.

     In a nutshell, set your monitor's color temperature to 6500*K, then 'Contrast'
to 100%, or as close to this as it will go. Most monitors will look fine at
100%, but if it goes funky, back off a little bit. Set the 'Brightness' at or
near 100%, then begin the 'Adobe Gamma' program.

     This is a simple 'Wizard' type dialog box, and you should see the sRGB
IEC61966-2.1 Windows default in the 'description' box... click next, but *don't*
use the simple grayscale target in the Adobe Gamma to set 'Brightness'...
instead, click 'next' again and use the gamma slider in 'Adobe Gamma', in
conjunction with the monitor's 'Brightness' control, and optimize these settings
simultaneously, while using Norman's targets, linked above.

     This sounds easy enough, but may take a little fiddling between the gamma
slider and the monitor's 'Brightness' control to get it right. Try to do this
under 'average' or 'typical' room lighting. Be aware of 'glare & flare'... but
doing this in a totally darkened room turned out to be a mistake for me!

     When it all looks good, finish the dialog... there's a 'before' and 'after'
check box to show you the difference you have made. Also, if you don't know the
exact phosphors your monitor uses, the HDTV setting seems the best choice for
generic CRTs.

     This can make an enormous difference in how your images, and other folk's, will
display on the monitor screen, plus how things print out... and isn't too hard to do!
 
--
 Geoff

http://home.att.net/~astropix/


--
 Geoff Powers

http://home.att.net/~astropix/
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