Question for Greg re printing

[imported_artmar]

Hi Greg,

In our last conference call you mentioned that CMYK is the colour space used for printing, and that it is a subtractive rather than an additive space, like RGB.  Out of curiosity, I looked at the printer cartridges used for my Canon inkjet photo printer. There are eight, labelled cyan, photo cyan, magenta, photo magenta, yellow, black, red and green. This seems to be a combination of CMYK and RGB (without the B). This raised some interesting questions which I have no idea how to answer: How are subtractive and additive colours used in combination? Why are there two different versions of cyan and magenta? Does the inkjet printer operate on different principles regarding colour interaction than offset lithography, which seems to be what is used for widely distributed publications and uses only CMYK. Does lithography produce a significantly better result than even a very good colour inkjet printer? In an ideal world where cost were no object, would one use offset lithography, or are there even better printing methods? 

Thanks in advance,
Art

[ggroess]

Art,

This one is an IN GENERAL Response....

When I talk about CMYK being a "printer" color space I mean it to be a "printing press" color space and I can see where you are confused because we all have "printers" Most printers use sRGB as a color space unless...You have a profile assigned to the printer and force the systems to use the profile.  That is why there are so many printer profiles out there.  Everyone has their own flavor of the printer...

Additive and subtractive colors are used for economy, it is cheaper to replace a single cartridge of say light Cyan than a whole cartridge of CMY because the Cyan is empty. Most people do not think Magenta, Cyan, Yellow they see and think Red, Green, and Blue.  Additionally more color cartridges gives you more "richness" in the image because instead of mixing more colors together you can bring Red in rather than Yellow and Magenta as a mix.

The reason for light cyan and light magenta is that those two colors are the most heavily used in the process.  When you send you image to the printer even if it is RGB the printer translates it to the "profile" and interpolates the colors needed for printing.  The usage of the pigments is "density based" if you have a darker cyan you use the Dark Cyan ink so you use less and the print dries faster.  All of these also use Black ink for additional density. 

Lithography with the right screens and skilled separation specialists can produce some stunning prints.  To print 1 copy you are better off getting a print from a local photo printer or your InkJet printer at home. Cost being no object I would go with one of the high end photo printers used by companies to produce photographic prints like you would find at a retail store.

Lastly, if you are interested in quality prints at home that is a whole different game to start learning about.  Having seen some absolutely stunning inkjet prints by Ctein and others; I would say you can spend more time learning about that whole arm of the process than you have already spend learning photography.  I personal;ly have profiled my system to my commercial printer and once or twice a year I make some adjustments.  I am satisfied with the quality of the prints I get in general but I can tell you that they are no match for a custom printer and process.

Great question and please ask more.  I will bring Mike into this if needed.  He's the output genius.
Greg

[imported_artmar]

Thanks Greg, I'm sure it's a very complex subject, and I'm going to ponder what you've written here, but have just one follow-up question for now: the high end custom photo printer and process you mention towards the end -- what technology that does use?

Would it be similar to the this one, or different?

http://www.canon.co.uk/For_Home/Product_Finder/Printers/Professional_Photo_Printers/PIXMA_PRO_1/

Cheers,
Art

[ggroess]

I'm talking about this...

http://www.fujifilm.com/products/photofinishing/digital_minilabs/lp7700/

You did say price was not an issue... 8)

[imported_artmar]

I'd like one of those Greg -- would have to build an addition to my house for it.  ;D

The Fuji specs say these printers use an RGB laser. But I thought CMYK had to used for printing in order to subtract the other colours from the white paper substrate (?)
(Canon colour laser printers use CMYK inks).

I have confusion on the brain.

Cheers,
Art

[ggroess]

A larger share of the printing industry is moving to RGB that is why some are saying, and Adobe is not preventing the death of CMYK.  There is a great deal of speculation in the color theory group that Adobe wants CMYK to die off.

I have not seen anything actively going on to cause it or prevent it...

Greg

[imported_artmar]

Hi Greg,

Does the colour theory group have a website? It would be interesting to visit.

In his  Professional Photoshop book, 5th ed., Margulis devotes part of Chapter I to a discussion of why RGB printing would be severely deficient. For example, he says "there would be no way to create bright intermediate colours like yellow" (and he continues in this vein). Has the development of RGB laser technology made such statements erroneous?

Cheers,
Art

[ggroess]

It is a yahoo group.  http://tech.groups.yahoo.com/group/colortheory/

If you go to yahoo groups and search color theory or Dan Margulis you will find them.  You will have to join the group to read anything important or search archives.

A BIG word of Caution...

These guys can play rough.  I read the forum for over a year before I ventured to even ask a question.  When I did I was shot down hard.  Not saying your experience will be the same but be careful about how and why you post.

It's actually one of the reasons we play so nice here at CM; we hate how they can treat people with honest questions out on some of the other groups. 

Greg

[imported_artmar]

Thanks for the tip Greg.
I'll join but wait a few months before I post my critical review of DM's latest book. ;D

Cheers,
Art

[ggroess]

LOL... that would be interesting as they are reviewing it line by line on the boards currently...

Needless to say I have not Drank the Kool-Aide.

Greg