Re: Trident 4
Re: Trident 4
- Subject: Re: Trident 4
- From: neil snape <email@hidden>
- Date: Wed, 22 Nov 2000 14:25:38 +0100
on 22/11/2000 12:26, neilB at email@hidden wrote:
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yes, but only up to the point of screen preview right now. The
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"export to workingspace" option appears to be broken at present, a
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fix has been promised. For the moment profile to profile in
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Photoshop is not a large price to pay for 16 bit profiled files I feel.
Yes this takes only a couple clock turns depending on the image size.
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My Howtek 4000 is old but very good I think. And Trident is a
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nice SW to use, even with my reservations about preview below.
Certainly are some expected expert colour balance features for people
scanning professionally. I've read the guides for the different versions but
would love to put this to practice on a Howtek.
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> Why should your mappings in the end points be restricted to preset values?
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I'm not quite sure what you mean. I'd like to be able to set the
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endpoint numbers myself before scanning the IT8 so I do the scan
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"manually" , saving the settings for future scans using the
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resulting profile. I am told that IPB tells the user to ensure
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the IT8 scan is clear of the 0 and 255 points before running a
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profile.
Depends on the method of implementing the profile against things like
dynamic base densities and white point issues. In Scan Open and ProfileMaker
(Steve or Henrik??) you can choose whether or not you have a dynamic profile
or one of fixed points. Still I think you're supposed to let the scanner see
raw rgb data and profile the device not the pre-emptive software correction.
Strange that Kodak would recommend setting end points before profiling as
once Joe Holmes said at that time it was only Kodak that extending good
shadow mapping into the very dark zones. What's important is getting it to
work as you have and not what different profilers say to do. Profiling
Epsons sometimes work better with their proprietary rgb driver pre
adjustments than profiling a way out raw chart. calibration before hand
always provides better results. Too bad for us with flatbeds that can't be
calibrated!
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mm - I am actually applying curves to the generation of a profile
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- because-
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I am I am compelled to scan the IT8 manually since IPB does not
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like the IT8 scan saved from Trident's "input icc calibration"
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routine.
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The manual IT8 scan requires either accepting the default Trident
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curve [which makes the IT8 too light] or a tweak can be applied
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and saved.
There's something definitely sideways here.
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well - I think they should be close to neutral since the IT8 film
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`"looks" neutral. Once I have made a profile, I open the IT8 file
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[the one used to make the profile] in Photoshop, converting to my
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workingspace from the new profile. Now I get almost exactly
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neutral numbers in the grayscale 127/126/126. This means that
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since the Kodak SW is providing a profile which corrects the IT8
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values to where the IT8 data file says they should be - the
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target must actually be almost exactly neutral.
I see quite a variation on IT8's and often a large red bias is possible. How
much would depend on the overlapping corrections applied from the deviation
tdf v.s. actual chart and profiling package into space AND rounding errors.
I'm sure Phil Green could tell us precisely.
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If I apply a profile made as above [no cast corrections] in the
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Trident SW's RGB blowback dialog [a version of display using
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monitor compensation]. I get really messed up numbers in the
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preview. Like I said previously, it's as if Trident is now
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measuring the numbers as if the preview is if in scanner space,
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which I suppose it is in a way.
Again Trident works sideways if this is the case.
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well, no, I got it dialed now, I just want the "export to
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workingspace" to operate as expected. Plus I'd prefer not to have
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to use two different profiles, one for originals which require
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cast correction by the numbers and one for those in which cast
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correction would be a mistake [eg. sunsets?]
In Lino Silverfast others it's appropriate to save the corrections to the
image types and apply them after the profile. I've tried modified source
profiles with Linocolor but the result numerically and visually was better
by leaving the profile pure and applying saved colour corrections.
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so you can see an accurate screen preview [accurate to the image
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appearance once in Photoshop that is], make the colour and tonal
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edits you want in the Linocolor SW, and then output to your
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chosen Photoshop workingspace with your user edits concatenated
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with the profile to profile conversion during the scan?
Exact.
The display of preview finescan and Photoshop 6 is identical no surprises
either visually or by numbers. I wouldn't recommend however going rgb>Lino
as it converts back to Lab.
Hmmm this is a tough one as to us scanning into rgb these are important
issues however as the cmyk world turns dot density they seem less
sympathetic to our needs.
--
Neil Snape in Paris