Message
Re: New to Linearize Piezo K7 inks with Eye One 2 X-Rite software
2015-02-10 by brian_downunda@...
@ Tyler
BTW, I'm on Win so I don't use print tool (sadly) and so have to pre-convert.
@Roy
Thank you for such a thorough exposition. Some replies.
. I'm in complete agreement that the NoCM & GG2.2 workflow leads to a print with weak shadows, at least initially before consequential edits, although the extent of this is very much image-dependent. I don't think that Jon has changed things much - he still wants K6/K7 curves that track that pink line exactly.
. I also agree that the CM & ICC workflow compresses the shadows, but this also is image-dependent.
. So for some years I've used a couple of techniques that try to work somewhere between these two. Putting or keeping weight into the shadows, but not too much and without losing detail of blocking up. Sometimes working in GG2.2 without CM and sometimes working in ICC with CM.
. I'm all for soft-proofing. It is the big advantage of the digital age over the wet darkroom, IMHO.
. And I think that converting to ICC does give the best screen to print match, but at a cost of the shadow detail, which I need to recover.
. It also linearises the printer, according to one usage of the word.
. Jon's approach also uses soft-proofing, but without CM you need to use the "preserve numbers" option. I usually don't find this as convenient a workflow, and it's harder to deal with a printer that is displaying non-linear behaviour, as in my first image.
So what's my point? Well, I'm trying to do two things, with Photoshop curves.
(i) I want to correct the non-linear behaviour of my printer, at least in the Jon Cone sense, ie. have it printing on the pink line. I think I can do this with a PS curve. I'm still refining it.
(ii) I want to be able to use a workflow that enables me to choose a point between linear in the Roy sense and linear in the Jon sense. I.e. a line that is as straight as possible between the pink and black lines in chart 2.
I've seen the Roark stuff. http://www.paulroark.com/BW-Info/QTR-Printing-Windows.pdf As you say, his curves simulate applying an ICC. I guess I'm trying to re-derive that curve for my papers more scientifically. Once I've got that I can choose what opacity to use for that curve. I can also create an inverse of that curve, which I can then use when I convert an image to the ICC, which also "linearises" the image, and then apply the inverse curve with some percentage opacity to partly reverse the ICC conversion.
For a number of years I've tried both of these approaches using the Roark curve and its inverse as rough approximation of the CM approach and I've been happy with the results, but want to improve on them.
Summary: Converting to GG2.2 opens the shadows and converting to the ICC closes them. I'm looking for a workflow that allows me to pick a point between these two and vary it as I choose. I'm also looking for something that allows me to iron out the idiosyncracies of my printer. I'm trying to use PS curves, but am open to alternatives.
But I still take issue with Roy's statement in his first post that "Just create a custom grayscale ICC built on top of the existing .quad file. Then print using this ICC. It has the same affect as relinearizing the curve plus you get thecolor-management system matching the embedded profile in your image." Yes it's linear, but it's a different kind of linear to that which the original Cone .quad was aiming for. I think that needs to be clear.