QTR-Quadtone RIP

Frans Waterlander wrote:
> Ernst,
> 
> Thanks for your reply. I think there may be some confusion about the 
> use of the term grayscale. For instance, when I use the Channel Mixer 
> and check the Monochrome box, I get a monochrome RGB image (three 
> channels, R, G and B and all pixels have the same R, G and B values), 
> not a grayscale, single channel image. As long as I keep my image in 
> the RGB mode, the Gray settings in Photoshop Color Settings don't 
> come into play. When you say that any other tone corrections should 
> be done in grayscale afterwards implies that you change the mode from 
> RGB to Gray and my point is that you don't have to do that at all and 
> stay in RGB mode "till the bitter end".

I didn't mention that last monochrome RGB>Greyscale step, but 
that's the one where no shifts in contrast and gamma should 
occur so where you should use compatible colorspace-gamma 
settings or at least know what you are doing. Whether you have 
to do that last step to greyscale or not is a matter of what 
you like to archive, a 3x bigger file or not. It is about what 
  you like for further editing, in greyscale or in color. If 
you think that you should edit  all in color before switching 
to greyscale (if ever) than that certainly is another approach 
than I use, I wouldn't trust myself in doing that.

> I don't want to nitpick or repeat what I have said in other posts, 
> but your recommendation to select either Gray Gamma 1.8 or Gray Gamma 
> 2.2 for the Gray Working Space is inconsistent with Roy's to use QTR -
>  Gray Lab (if you don't want to use the RGB mode). 

There's hardly a difference between Gray Gamma 2.2 and 
QTR-Gray Lab in practice. I use QTR's Gray Lab. Steve Kale 
uses Gamma 2.2 and a lot of other skilled digital B&W printers 
do the last too. The Gray Lab should be a fraction more 
perceptually correct but both the quality of your monitor's 
calibration and to what it is calibrated is more important. 
When you convert to the QTR paper profiles from 2.2 or Gray 
Lab you get the perceptual curve for the tone range of that 
paper and that is the really important last step. Where you 
see inconsistency there isn't one in practice.

On documentation I could agree but I'm no volunteer either for 
that. When you grow slowly into digital B&W printing and were 
part of the development by commenting, trial and error, 
suggestions in the lists, DIY attempts in your own shop you 
understand that QTR's documentation is just a small part of 
the learning process. That learning process goes along 
different routes for users, what seems logical to one isn't to 
the other. Different expectations of what should be available 
in shareware software is another one. Lately I see some 
messages on more lists where newcomers express a lack of 
patience for that learning curve combined with a critical mood 
on what is available. There was an artisan skill and thorough 
knowledge needed in the wet darkroom for good printing and I 
believe that applies to digital printing too. It wasn't  "you 
press the button and we do the rest" in the past and it isn't 
right now, not to speak of the many extra buttons we have 
today. The ordinary consumer is still amazed when his digital 
pictures appear wirelessly on the display, the "developed" 
pictures fall on the doormat but the underlying complexity and 
what has to be done to make the best print has nothing of that 
simplicity right now and I wonder it will ever be like that.

And that's an
> issue that I see a lot on this forum: recommendations that are 
> inconsistent and/or contradictory. I rest my case for an overhaul of 
> the documentation.

There's no contradiction in my opinion, there may be some 
confusion about what could be contradicting. This forum is the 
best digital B&W printing forum you will find on this planet. 
You have to do with it like we all do.


Met vriendelijke groeten,  Ernst


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