ISO spec for Digital Darkrooms (was Re: Monitor calibration)
ISO spec for Digital Darkrooms (was Re: Monitor calibration)
- Subject: ISO spec for Digital Darkrooms (was Re: Monitor calibration)
- From: Jack Kelly Clark <email@hidden>
- Date: Fri, 19 Oct 2001 08:07:23 -0700
On Thu, 18 Oct 2001 14:02:28 -0500, email@hidden (Anthony Sanna)
wrote:
> OK. Here's another turnip to throw into your digital soup. Jack Clark
and I were just discussing the effects that screen brightness might have
on color editing. My old PressView could barely hit the low 70's on a
good day at D50, while my new Sony can be D65 calibrated with brightness
as high as 124 cd/m2.
I run the Sony at 90 cd/m2, however, and have always assumed that the
extra brightness would not affect Photoshop editing. However Jack
pointed out that the extra brightness might create a situation where
shadow detail appeared too open, thus yielding real-world output that was
blocked up.
So in addition to all the other variables mentioned, where does screen
> brightness fit in?
And, before I could chime in, Dan Reid replied:
A working draft of the upcoming ISO 12646 (soft proof comparison of
screen to print) recommends at least 100 cd/m2 and should be more than that.
I had excellent match between the Cinema Display 130 cd/m2 and some of the
viewing booths I reviewed for an upcoming PEI article. The Cinema Display's
higher luminance level necessitated less compensation [dimming or dumbing
down :) ] of the light booth to balance with the screen's perceived
illumination. Luminance level does not effect your shadows it just
increases your dynamic range from black to white. Personally, I think a
bigger dynamic range is ideal. The bunk floating around about pushing the
luminance level will prematurely age a monitor is a myth. I have been
running an old Lacie 21/108 for several years at 100 cd/m2 and am still able
to hit that target luminance level even with the monitor on every day --
sadly, I still work weekends :(
Several years ago I heard a rumor that an ISO specification was being
developed for "digital darkrooms." Presumably it would address all
the parameters necessary to control to achieve the best results in a
visual image editing environment (e.g., monitor calibration, ambient
lighting intensity/color, and, even the shade of gray paint on the
walls). In other words, it would be an official extension of the
"White Paper on Digital Darkrooms" put forward by Radius when they
were hot and heavy into this business. Is the above mentioned ISO
12646 part or all of this "digital darkroom" spec.?
As Tony mentioned above, I'm running our monitors a little darker
than he is (between 80 and 85 cd/m2), with good results from a
variety of offset print vendors dotted around North America (we make
a custom profile of their proofing systems before the job is run).
The ambient lighting levels around our digital darkroom work stations
are adjusted lower than regular office lighting levels. No
measurements have been made because I was eventually going to try and
search out that promised ISO for digital darkrooms and hopefully find
the ideal ambient light level listed there. Now Tony and Dan have
forced me out into the open on this, which is probably a good thing.
;-)
In thinking about this over the past 24 hours (a dangerous process),
it suddenly occurred to me that maybe the really import thing to
consider is the simple ratio of screen brightness to the ambient room
brightness in the digital darkroom. Any and all thoughts on this are
welcome.
Oh, BTW, three years ago we switched over to D65 gamma 2.2, and have
never looked back.
--
Jack Kelly Clark
Principal Photographer
ANR Communication Services
University of California
Davis, CA 95616
(530) 757-8987
http://anrcatalog.ucdavis.edu