On Monday, June 30, 2003, at 04:12 PM, kiwikale wrote:
> Ok I can see the differences in the step file and I will take another
> look at/redo the
> test prints. Can I ask why Gray Gamma 2.2 vs 1.8 (ie the default
> gamma for Macs)?
>
> Also there is an enormous amount I have to learn about curves etc.
> Where is a good
> place to start? I was reading some of the workflow material on the
> MIS website. I
> guess I can simply "follow instructions" but that isn't really enough
> for me. I would
> like to understand this stuff - at least partially. For example, I
> was really puzzled as
> to why one would "Edit the image in grayscale mode, save it, and then
> convert the
> mode to RGB for printing." The color world seems relatively straight
> forward with the
> use of ICC profiles while B&W seems to be all over the place. Any
> pointers to
> tutorials/books etc would be greatly appreciated. I need to start
> with the basics.
>
> (Also if anyone knows any good courses in this stuff in the London
> area I would
> greatly appreciate it.)
>
>
>
>
>
> --- In DigitalBlackandWhiteThePrint@yahoogroups.com, Carl Schofield
> <scho@m...>
> wrote:
>> You should see a dramatic difference in the prints made with a gray
>> working space of gamma 2.2 and Dot Gain 15, if the image file has been
>> converted to those respective working spaces before printing. Try the
>> following to make sure your settings are correct and that you have an
>> image file that is properly tagged:
>> 1. Set your gray working space in Photoshop to Gamma 2.2.
>> 2. Open the 21-step.psd file (from the QTR images folder) in
>> Photoshop.
>> It should be already tagged as gray gamma 2.2, if not convert it.
>> 3. Page setup - select your QTR 2200 printer from the list in "Format
>> for:"
>> 4. Print with preview - you should see Source space selected and
>> Document: gray gamma 2.2 and Print space: Profile should be set for
>> Same as Source.
>> 5. Print: make sure again that your QTR 2200 printer is selected in
>> the
>> printer list
>> 6. printer features, basic: matte paper, 1440x720 Highest quality,
>> photograph, adaptive hybrid, and seven color.
>> 7. printer features: QTR settings, output mode: quadtone rip, curve 1:
>> 2200-warm, curve 2: 2200-cool, blend: 50-50 (or just select one curve
>> with blend at 100-0).
>> 8. print
>>
>> Here is a plot showing the density curves for the above mentioned
>> file,
>> printed as described above and printed again after conversion to a Dot
>> Gain 15 working space: http://homepage.mac.com/scho/comp.jpg
>> I think you can clearly see that the densities are higher for the Dot
>> Gain 15 print and that this print is also flat in the shadow area.
>>
>> On Sunday, June 29, 2003, at 03:29 PM, kiwikale wrote:
>>
>>> --- In DigitalBlackandWhiteThePrint@yahoogroups.com, Carl Schofield <
>>> scho@m...> wrote:
>>>>
>>>> On Sunday, June 29, 2003, at 06:36 AM, kiwikale wrote:
>>>>> So far I have just run 3 test prints using the settings
>>>>> suggested/corrected in
>>>>> earlier postings (now print space in PS "same as source", 1440x720
>>>>> Highest
>>>>> Quality etc): Roy's QTR (2200) neutral and warm and then a straight
>>>>> Gimp
>>>>> 4.2.5.
>>>>>
>>>>> In the 2 QTR prints I found I lost a lot of detail in the shadows
>>>>> vs
>>>>> using the
>>>>> Epson driver (defining the print space in PS as the ICC profile for
>>>>> watercolor
>>>>> paper with the matt black and no further "color" mgt). The prints
>>>>> were as if
>>>>> there was a loss of about 1/2 - 3/4 stop exposure. However, the
>>>>> Epson
>>>>> driver
>>>>> tends to be plagued by a degree of metamerism as we all know.
>>>>> Tough
>>>>> trade
>>>>> off as in the test print I did the metamerism was not that bad and
>>>>> the
>>>>> loss of
>>>>> shadow detail in QTR was. I guess this is because with QTR the use
>>>>> of
>>>>> color
>>>>> is restricted to govern metamerism and hence tonal range is
>>>>> reduced?
>>>>
>>>> I was able to reproduce your problem with poor shadow detail and it
>>>> appears to be due to the Dot Gain15 gray working space you were
>>>> using
>>>> in Photoshop. I suggest that you use gray gamma 2.2 instead to
>>>> eliminate this problem and if your file has the Dot Gain 15 profile
>>>> imbedded make sure it is converted to gamma 2.2 in Photoshop before
>>>> printing. You should then be able to get good shadow detail with
>>>> the
>>>> 2200 profiles.
>>>
>>> Hmmm..... I tried this but to little avail. I also tried Gray Gamma
>>> 1.8 which I
>>> note PS says is the default gamma for Mac OS computers like mine.
>>> All
>>> three
>>> prints are, as best as I can tell, identical.
>>>
>>> I am wondering if the effect that I am witnessing is simply the Epson
>>> driver
>>> "pushing" the exposure a tad.
>>>
>>> At any rate, I am getting even more puzzled by a "same as source"
>>> workflow. I
>>> went through the videos on the piezography website today. Their path
>>> of
>>> establishing an ICC profile for a particular ink, paper, printer
>>> combination
>>> makes intuitive sense to me. You can proof setup and, theoretically
>>> at least,
>>> what you see is what you get. That is, the mapping of colour or
>>> grayscale
>>> reproduction (as I understand it) is done within PS at the proof or
>>> print with
>>> preview stage and not by the print driver. In a same as source
>>> workflow any
>>> mapping is (as I understand it) done outside of PS and so changing
>>> the
>>> workspace in PS should not affect the output (assuming the print
>>> driver is
>>> equally adept at mapping all of the various PS workspaces).
>>> Therefore
>>> I am
>>> somewhat comforted to find that it did not affect things today else
>>> my
>>> general
>>> understanding of all this stuff would have been really screwed up.
>>>
>>> When Gimp or others say they have tuned matt black and watercolor
>>> paper for
>>> the Epson 2100/2200, are they in part saying that (a) the driver can
>>> recognise
>>> automatically whether matt is loaded and (b) therefore when you
>>> select
>>> watercolor paper it loads and uses a profile for that printer, matt
>>> ink,
>>> watercolor paper combo?
>>>
>>> Confused....
>
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