QTR-Quadtone RIP

Hi Steve. I don't think we disagree at all. As you said(below)

> Though it is not too intuitive, an analogy is that PC monitors
calibrated to
> gamma 2.2 monitor have a darker display for the same RGB values sent
to Mac
> gamma 1.8 monitor. Since gamma 2.2 displays darker, 92% black on a
gamma 2.2
> monitor would be the same level of gray as 96% gray on a gamma 1.8
monitor.


they do not "look" the same for the same values. My point is that we
edit files by looking at them and being able to better see
distinctions in deep shadow areas is helpful in doing this. It also
turned out for me that it closely matched the "view" given by
softproofing with Graymatt.icc. That meant it was more wiziwyg with
the resultant prints. I don't know why that should be unless the
linearisation undertaken by QTR is giving the same "visual" spacing to
the hardware output as gamma 1.8 does to the screen. If, as you noted,
2.2 at 92%K looks as dark onscreen as 1.8 does at 96%K it would mean
that the next 8% of 2.2 values would be squeezed into only 4% of
remaining monitor space for a 0 to 100% screen range eg:compressed
visualy although not numericaly in the sense of the file numbers.

It is anything but intuitive dealing with the whole issue of spaces
and color management I most assuredly agree. The strange thing about
the softproofing process is that(to me at least) it appears to be
doing something that everyone who knew a little about color management
had fits about. ie: adjusting the monitor to match print output
instead of setting up the printer via profiles to match a fixed
colorspace. It is not quite doing that, of course, but it sure comes
close. It does adjust your monitor to show you what you will get if
you print the file as is. I am not a luddite and I use every
technological tool I can afford but, frankly, what I care about is
knowing what the output will look like. Anything that easily enables
that is what I will use.

Ken's issue of not getting what he sees on screen would mean to me the
same as what you indicated. There has to be a problem somewhere in his
setup. Either his monitor is not correctly profiled or his printer is
not truly linearised or there is something in his workflow that is
being missed.



--- In QuadtoneRIP@yahoogroups.com, "Steve Bye" <steve_bye@...> wrote:
>
> Duane,
> 
> You know the process for using QTR profiles better than I do. I can't
> comment on that. But I want to clarify something I said that I am
not sure
> you agree with.
> 
> My point is that 96% K in a gamma 1.8 space and 92% K in a gamma 2.2
space
> represent exactly the same density -  it is a density of 2.4. You cannot
> compare the K values of spaces with different gammas. You can
compare the
> densities.
> 
> Am I missing something?
> 
> Steve
> 

I don't know about the density thing. It wasn't something I gave
thought to. I'm not sure about your 2.4 figure though. I don't think
workspaces have any direct connection with the physical density of a
printers output. In my understanding it's like a universal pie cutter.
Whatever the size of the pie, it whacks it up into 6 (in this case 100
symbolic) pieces. That is why it is called device independent I think.


Regards
Duane




> Behalf Of dlruckus
> Sent: Saturday, June 03, 2006 12:47 PM
> To: QuadtoneRIP@yahoogroups.com
> Subject: [QuadtoneRIP] Re: Roy's working space blocks up shadow
detail? Why
> use it?
> 
> You don't want to convert to gamma 1.8. Just assign that as your pshop
> working profile for future use. As noted in a later post here by
> another, the 2.2 and 1.8 do differ in the %K shown between the
> workspaces. Mentioned is 1.8 96% vs 2.2 92% levels looking the same.
> That 4% visual difference is enormous at that end of the scale when
> you are editing a print.It means that you are also likely seeing
> values of 98% or better as different from 100% onscreen.It indicates
> that 1.8 is expanding the shadow areas visually by a factor of 2. If
> you are already seeing good shadow detail onscreen with what you are
> currently doing but not getting it in print, using the Graymatt.icc to
> softproof in photoshop should be showing a drastic change when you set
> it up and then check and uncheck( turn it off and on). The point of
> softproofing is to use the printers icc profile view to edit your
> photo so that it's values do match for your printer/paper/ink
> characteristics. You must have your monitor properly set up and
> profiled for all this to work as well. Likewise if your printer is way
> out of sync with the generic Graymatt.icc profile, it won't work right
> either. Note that you would want to do most of your editing genericaly
> with one of the available workspaces and do the final print editing on
> a copy intended for use with the specific printer etc.In other words
> save a master, make a copy and edit it with graymatt.icc or other
> softproof for the specific printer turned on. If your printer is
> indeed linearized this will work. It ought to work no matter what your
> workspace is. You are simply doing in pshop what you don't want to
> have to do with the slider in QTR so as to not mess up your printers
> linearization.
>  My comment about using gamma 1.8 to edit and not gray_lab was just to
> say that I found no changes necessary between it and the graymatt.icc
> softproof view to get the tonal values I wish.
>  As regards Roy's comment, I don't think he meant that you couldn't
> use the graymatt.icc to softproof for luminance. It has always worked
> fine for that. I think he was referring to being able to use the
> create_icc tool for icc's that work to softproof not only for
> luminance but also show color tones eg:sepia,cool etc.
> 
> Hope I have clarified my posting a bit.
> Regards
> Duane
>