Re: Mac vs PC gamma difference
Re: Mac vs PC gamma difference
- Subject: Re: Mac vs PC gamma difference
- From: Steve Upton <email@hidden>
- Date: Thu, 13 Dec 2001 01:08:36 -0800
At 5:46 PM -0500 12/12/01, Todd Flashner wrote:
I'm confused about the gamma difference between PCs and Macs. Is it real or
is it convention?
90% convention
Is it just monitor calibration conventions that is the difference - that
Macs users have traditionally calibrated their monitors to 1.8 and PC users
to 2.2, but at an OS level there is no difference?
yup
Or is there actually a
difference in the OS or in the programs run on each system?
well, apparently Quickdraw in the Mac is setup to assume a 1.8 gamma
but I'm not sure exactly what that means anyway.
The 1.8 gamma does a better job of simulating ink on paper (or I
think it was for toner on the original Laserwriter printer). So on an
unprofiled and otherwise uncalibrated system 1.8 was better for print
work.
In the real world, if the two systems have their monitors calibrated to the
same standard, lets say 6500K 2.2g, would printer profiles made on one
system apply perfectly to matched hardware on the other OS, or do different
profiles need to be made for each OS?
Well, this depends on whether the application (or OS) displaying the
image sees the profile and can use the gamma of the monitor to modify
the image for correct display. Photoshop does this from 5.x on
FWIW, Here's the nitty gritty of my situation. I've been given RGB ink
separation curves for printing monochromatic quadtone inks through the Epson
driver. They were created by someone using the same inks, printer, and paper
as me, but he's PC, I'm Mac. Using the same curves and driver settings, my
printouts are darker than his. Thus, I'm wondering if this is due to OS
gamma differences. I'm also wondering if this gamma difference is a known
quantity such that there is a predefined curve, transfer function, etc.,
which would make quick work of utilizing the existing curves across systems?
I don't think it is this simple but it might be related. You need to
see what the gamma of you respective working spaces is and then
consider the assumed input profile/gamma for the Epson driver on each
platform. Both gamma issues, neither of them monitor related.
As this person is scripting such curves for several different printer models
it would be very nice if he did not have to duplicate his efforts for each
I think you should be able to avoid it..
Regards,
Steve
________________________________________________________________________
o Steve Upton CHROMiX www.chromix.com
o (hueman) 866.CHROMiX
o email@hidden 206.985.6837
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