Digital BW, The Print

Diane 

I bring an image into PS as Adobe RGB.  Use  Split Channels to get to a B&W
composite,  Assign my working space - QTR Grey Lab - (because after
splitting the channels the image does not have an embedded ICC profile) and
then edit away in Grey Lab.  Most B&W conversion techniques that I am aware
of leave the file in your grey space anyway so you have left Adobe RGB.  I
use Photokit Sharpener Pro.  Capture sharpening is done while the image is
still colour.  Print sharpening is done with a simple conversion to Adobe
RGB (and back again) once I have finished editing and am ready to print.
People might argue that this is destructive but given I use 16bit and it is
the very last step I don't care.  While editing I can proof to either matte
or photo paper but will typically only do this at the last step and apply a
"print curve" (none is really needed for photo paper).  A good reason to use
Lab or Roy's L as a workspace is that because it is Lab's L channel L=50 (ie
the 50% step) corresponds to Kodak grey.  So if you know that you want a
certain part of the image to be 18% reflectance then you can work towards it
easily.  The bottom line is I find Lab (less the a and b) to be more
intuitive.  

Of course, perceptual rendering won't necessarily leave image L=50 luminance
at L=50 reflectance but you can print an L step wedge to see where each step
gets mapped to - I think....someone who understands Perceptual rendering a
lot better than me can chime in here: is it image dependent or a mapping of
greyscale that can be measured by printing a Lab step wedge?  BTW is there a
way to read the proof image values ie the pro forma image values for a given
proof?  My understanding is that there is not and that PS will only display
(Info palette) the image values.

So all my B&W files are tagged QTR Grey Lab.  I use a Mac and can have PS do
the conversion on the fly to Matte or Photo Paper profiles at printing.

Steve


> From: Diane Fields <picnic@...>
> Reply-To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
> Date: Wed, 23 Mar 2005 18:36:12 -0500
> To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
> Subject: Re: [Digital BW] Quadtone RIP Faded print
> 
> 
> I'm new to QTR, but I will tell you my reason for not using it as my working
> space--but rather have it as my 'proof'--meaning I convert to it.  I prefer to
> work in Adobe RGB98, process as b/w (and use a variety of ways depending upon
> the image)--but I don't convert to LAB until the end (and then to gray-matte
> paper, my usual paper).  I can't use PKS in grayscale for one thing--and this
> is normally my last process before printing.   I'm watching to see how others
> handle this, but that was my understanding of how to handle it--as a
> 'conversion'.  It works well for me.  If I need to do just a bit more to the
> file before printing, I can still  add an adjustment layer to it, but I've
> done most of my work in RGB, 16 bit (and, in fact, most of it besides the b/w
> conversion, was done before the RAW conversion since I shoot mostly digital
> RAW).
>