Keith Cooper wrote:
An interesting discussion that likely relates to an issue I've seen in printing B&W photos.
This from a qualitative POV...
In using either B&W print modes (ABW or Canon) or icc profiles there is frequently a tendency to crunch deep shadow detail in varying amounts for images on a wide range of papers.
The normal explanation for this using ICC profiles, is using a colorimetric intent with an idealized source colorspace (i.e. sRGB, AdobeRGB, ProPhoto), since then all input values below the black point of the printer will be clipped.
Typical fixes are BPC or a correctly gamut mapped output profile using perceptual intent, or the equivalent device link workflow.
Whether this explanation is applicable to your situation is something you will have to explain, since it very much depends on technical details of your workflow.
Graeme Gill.
Thanks Graeme - I was looking for a relatively simple solution that could apply to printing a monochrome image (e.g. 16 bit B&W photo in GG2.2) from Photoshop using the relevant Canon or Epson driver (oh, and on a Mac since I don't have any PCs here to try) - I say relatively simple, since I'd like it to be something that I could share with non printing/colour management experts - Let's say I've got a PRO-2000 and a P7000 in my office. Let's assume I want to use two different papers, one a heavy lustre baryta type (pk ink) and one a heavy cotton rag (mk ink) I could use Epson ABW or Canon's B&W print mode, but they have limited controls. Still they can work well for some images on some papers. One approach would be to use a normal profile (say from i1Profiler, since I have a copy) with or without BPC as looked best for the paper and RI Doing this can make for some good looking prints, but is where I notice the tendency to crunch shadows, which led to my initial query. This is where I noticed your mention of: "a correctly gamut mapped output profile using perceptual intent". Could my 'shadow crunching' be a result of this not happening with my i1Profiler profile, for a B&W source image? I know the 'limited nature' of the adjustment sliders in i1Profiler has been a matter of concern in some previous discussions here ;-) I'm well aware of the need to allow for media colour and the darkest blacks being not quite black (I did say I was looking from a qualitative POV) but the shadows crunch is often enough to need to expand them a bit (in PS) before printing. I'd rather that this was not needed. Any other suggestions for printing a B&W photo from Photoshop with the normal OEM driver would be welcome. Note specifically 'from Photoshop', not via some extra print software. I've used TrueBW on Canons for example and also looked at QuadToneRIP. Both these have specific linearisation options for dealing with the issue I'd noticed, but as I said I was looking for a possible simple approach for the photographer just printing B&W photos from Photoshop (or LR, but I don't use it) Bye for now Keith Cooper