Digital Negs - RGB vs CMYK

From: Michael Healy ^lt;[email protected]>
Date: 12/01/04-01:54:15 AM Z
Message-id: <41AD1637.5613.87563D@localhost>

Now that the smoke has cleared a bit, I'm going to be rash and stick my neck waaaaay
out there with a few little quasi-neophyte questions. I want to be clear about something,
though: I am not interested in getting up people's dander, or getting myself tangled up in
the age-old argument over which color mode is sacred. I'm interested in understanding -
for home printers - why there is a differences between these modes to begin with.

Now, I understand the requirements of a printing house: CMYK since Gutenberg. My
problem, though, is that I happen to print my negs on an Epson inkjet printer that's
sitting here at my elbow. Okay, so one way I can print my negs - or my separation negs -
is to leave them as RGB; then again, I can take the trouble to convert them to CMYK
before I print them. I gather that some people grow hives at the thought of one, while
others are growing second and third heads at the thought of the other. The whole thing
gets me totally hung up, though. Here's why: the last time I looked, my Epson was using
CMYK inks. To my uninitiated eye, it doesn't seem to matter what I do with my file - the
thing is going to get ripped as a CMYK file, period.

So what is it that I am missing? I can convert a neg (or its separation components) to
CMYK, and then won't it print as CMYK, unaltered? Or I can be lazy and leave it as
RGB. Then the printer intercepts it, and converts it to CMYK anyhow, and then prints it
as CMYK.

So I am wondering about three things:

(1) what difference does any of this make, if the thing has to end up CMYK anyhow?
Why does it matter what your Photoshop mode is (assuming it is color, not b&w)?

(2) If it is true that both RGB and CMY get turned into CMY by my inkjet printer, then In
terms of inkjet printing (NOT print shop printing!), what exactly is it that CMYK
advocates are advocating, that I should take this extra step to convert it? And what is it
that the RGB advocates are missing, that they think they actually are pulling off an RGB
print through a CMYK printer?!

(3) GUM! If an inkjet printer does print CMYK, why do people use painter's (RGB)
colors? It would seem to **require** that one use printer's (CMY) colors - assuming, at
any rate, that one wants "realistic" colors. How come RGB pigments used on inkjet negs
don't turn a gum print into something resembling cross-processed C41?

Received on Wed Dec 1 01:54:44 2004

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