How can I determine whether my printer can _directly_ print CMYK? 2

[JeroenStamps]

Sorry if it is something that is so simple, I couldn't find it;

I read the FAQ's about printing (this forum, and googling for it), and think I now know quite well how printing works, and that RGB (screen) images must be converted to CMYK before printing, but that mostly the printers take care of this for you (internally). I think I understand that.

Now, I read that offset printing requires you to deliver the pictures in CMYK. But how can I know whether my printer understands it as well, I mean, it prints CMYK, so it probably should let me print those colors directly, bypassing any printer-based colorconversion, right?

It's a Minolta-QMS Magicolor 2350 colorlaser.

The manual says it can do all kinds of colorconversion, color profiling, and stuff, but I am not sure it prints CMYK directly without converting the colorspaces first.

Besides which, if my printer understands CMYK, how can I force my application (Photoshop) to send the image as CMYK to my printer?

NOTE, to be honest, I just now thought of the second question, I haven't really searched for that one on google. My primary question is most important to me...

Thanks for any reply in advance.
Jeroen

 

[JeroenStamps]

Additional info, (RTFM) the manual has to say the following:

(Quote
"First, the RGB Source ICC profile
translates RGB values of the color
producing device (in this case a monitor)
to the standard CIE LAB color
model. Next, those CIE LAB model
values are translated into a Simulation
profile, if the user chooses to use one.
If a Simulation profile is used, the color
data is once again translated to the
standard CIE LAB color model. Finally,
the MINOLTA-QMS Output or Destination
profile converts the translated
data into CMYK to be sent to the print
engine."

Does this mean I indeed _CANNOT_ print CMYK directly?

 

[duncdude]

i'm pretty sure that if your image is in CMYK within PhotoShop then it will just print straight to your printer - your printer is PostScript I assume?


Kind Regards
Duncan

 

[Eggles]

I have found that most desktop printers (as opposed to offset) will print images sent in either CMYK or RGB. Most 'lower end' printers (usually non-postscript inkjets) in fact 'prefer' images to be sent as RGB, because it assumes it will have to make an internal conversion to CMYK anyway. If you send a CMYK image to one of these printers, they can often undergo a double conversion (perhaps because they don't 'recognise' CMYK being sent) and the results can sometimes be an unpleasant surprise colour-wise.

Postscript printers seem to recognise CMYK images being sent to them, and print them just fine. But they can also print RGB images.

Why not just send two copies of an image to your printer - one in RGB and the other in CMYK and compare the results?

 

[JeroenStamps]

Thank you for your replies, I have one simple question now, how do I force photoshop to send as CMYK? I mean, just converting my RGB picture to CMYK using the "Image -> Mode" feature is not enough, I presume?

Especially as I read that I need to send a PS file? How can I then easily convert a picture to a PS file of which I can be _certain_ that it is in CMYK format?

 

[duncdude]

I'm sure it is enough to do just that!

RGB -> CMYK -> send to printer. JOB DONE!

Unless I have missed the point somewhere!!!


Kind Regards
Duncan

 

[JeroenStamps]

OK, thank you very much, I'm gonna try that.

Just curious though, what happens if I do that while having a simple deskjet or something? Does the deskjet internally convert it to RGB first?

 

[duncdude]

I think it's a little more complex than that. Unlike PostScript printers, inkjets are dumb. They print (I believe) using Quickdraw information - the same that is used to display images on the screen, You must remember that even though you have a CMYK image on screen that you are still viewing it on a monitor - and all of them are RGB!


Kind Regards
Duncan

 

[Eggles]

>>Does the deskjet internally convert it to RGB first?<<

If by 'it' you mean send it an image as CMYK, I already answered that I think.

>>I have found that most desktop printers (as opposed to offset) will print images sent in either CMYK or RGB. Most 'lower end' printers (usually non-postscript inkjets) in fact 'prefer' images to be sent as RGB, because it assumes it will have to make an internal conversion to CMYK anyway. If you send a CMYK image to one of these printers, they can often undergo a double conversion (perhaps because they don't 'recognise' CMYK being sent) and the results can sometimes be an unpleasant surprise colour-wise.<<

The 'double conversion' I referred to isn't quite as simple as CMYK -> RGB -> CMYK. I think they go via another colour mode called LAB (or CIE) which is why the final printed colour can sometimes be a total surprise.

 

[JeroenStamps]

Eggles:

The Manual of my Minolta indeed says it converts it first to LAB (See 2nd post). Therefore, I'm not so very sure that it prints CMYK directly. It _may_ first transform it to LAB and back again...

Furthermore, I printed a picture converted to CMYK first, and it prints something different. BUT (!!) although both prints are different, they both deviate quite a bit from the screen picture, neither is necessarily better.

I think I must therefore now search for a calibration solution (I hoped I could bypass that using direct CMYK print, that although it would not be calibrated, it would give me pictures sufficiently accurate). But alas, they're quite expensive (maybe not for what they have to offer, but for me who just bought a color-laser).

My first choice would be EZColor from monacosys.com. Anyone experiences with that?

 

[JeroenStamps]

O, darn, forgot to ask a calibration-related issue in my previous post;

* When calibration software says &quot;Don't f**k with your settings --> leave everything at default (to let the color profiling do all the color stuff)&quot;, does that mean &quot;Leave the pictures to print in RGB&quot;, or should I still use CMYK to print them...

I think that is confusing, since I would think sending pictures as CMYK would _not_ be the default printing choice, BUT prints using CMYK should be more neutral, and therefore the colour profile wouldn't have to adjust the colors that strong, am I right in this assumption?

How do you print when using colour profiles, or do you even have two profiles, one for RGB, and one for CMYK printing?

Kind regards, Jeroen

P.S. Never thought I would be really getting into this colourprofiling stuff Maybe it has to do with the fact that I am slightly disappointed with the default print quality (regarding colors) of the machine :-(

 

[Eggles]

Jeroen

I don't bother with colour calibration. More trouble than it's worth. I just accept that printing CANNOT reproduce what you see on screen accurately, since they are using two completely different processes for displaying colour. After a while, you learn to recognise where pictures won't print true. And accept that sometimes the results are disappointing. Haven't you ever experienced the same thing with photographic prints?

As to whether you should be sending your images as RGB or CMYK depends entirely which result you prefer. I tend to leave mine in RGB, unless being offset printed, when CMYK is mandatory. Stop worrying about it and just enjoy it.

 

[duncdude]

I think Eggles is absolutely correct - so many people worry about all sorts of tiny little things - and get completely confused in the process - this sort of madness would mean that people would be calibrating their monitors during different hours of the day because of the different colour temperature of the sunlight shining through the window. Believe me that sunlight sure does change colour during the day - and I can't be bothered to worry about that!!!

Leave the settings alone - apart from a select few that is - as Eggles says!


Kind Regards
Duncan

 

[JeroenStamps]

Thanks for your insight in this matter! It is indeed an eye-opener to view this subject from a different viewpoint (i.e. that non-perfect colormatching is not the end of the world).

Regardless (Programmers are stubborn people), I still want to get a bit closer to what I want to print, especially when I scan from an original.

I mean, I scan something from a CMYK original (although it is converted to RGB by the physics of the scanning process)? That means I could at least print something quite close to it, I guess...

At least I will now know better when to stop (be content with your work, instead of looking for the perfect match), thanks to your valuable meta-remarks.

Thanks again for all your comments!