Re: Digital Negs - RGB vs CMYK

From: Jim Morris ^lt;[email protected]>
Date: 12/02/04-11:12:57 AM Z
Message-id: <>


For the purposes being discussed, I believe using either RGB or CMYK
files can provide similar, if not the same, results. The only real
difference between the two, for the purpose of separation films, is
that RGB files have three channels and CMYK files have four channels.
In my opinion, using RGB negs. is a simpler approach, but CMYK offers
more options if you are willing to explore the settings. It's true
that if you simply use the "default" CMYK settings in Photoshop you
will need to use the K printer film as it will carry a significant
amount of the image's information, but you can "choose" to generate a
CMYK file that only carries information in the CMY channels and leaves
the K channel empty, in this case it may be simpler to use RGB.
However, if you "choose" to use K when you make your prints CMYK negs.
would be more appropriate (of course you would have to select the
proper settings in your CMYK set-up). That brings up another point, if
you decide to generate all the image information in the CMY channels
you can still use the K channel for something other than black, perhaps
a spot color or a film that can selectively bump-up one of your
printing colors, etc. In my opinion, CMYK offers more options than RGB
but at the expense of simplicity.

Jim Morris
DCP, Inc.

On Thursday, December 2, 2004, at 08:21 AM, Christina Z. Anderson

> On p. 53 he says he prints the yellow gum layer with the yellow neg,
> the magenta with the magenta, and the blue with the cyan. He does not
> use the K.
> Not having ever done CMYK, is this a typo, or those of you who do use
> CMYK do you use the negs like this? Or is it just that the service
> bureau he uses labels the negs this way? In other words, RGB negs use
> the R for cyan, the G for magenta, and the B for yellow.
Received on Thu Dec 2 11:14:20 2004

This archive was generated by hypermail 2.1.8 : 01/03/05-09:29:43 AM Z CST