Re: Epson7000: Absorption/ReflectanceReadings
Re: Epson7000: Absorption/ReflectanceReadings
- Subject: Re: Epson7000: Absorption/ReflectanceReadings
- From: Steve Upton <email@hidden>
- Date: Fri, 29 Dec 2000 10:31:03 -0800
At 7:21 AM -0600 12/29/00, Mark Tucker wrote:
1. Even though this sheet is coated, is there a possibility that the
inks would absorb "more" in these more saturated areas? I built a curve
to try to alter this and it's worked pretty well. I tried to isolate
only the 90-100 areas.
Actually the coating of the sheet is typically designed to absorb
ink. Then you get a much better bonding with the paper and the paper
can take more ink without puddling. I only makes sense that the paper
absorbs more ink in saturated areas - there's more ink printed.
2. Why do profiles have both a name and a description? It seems that
sometimes a profile is known by one or the other in a pull-down menu.
What's the purpose in this two-pronged approach? It seems only to risk
confusing matters.
The internal description "desc" name of a profile was intended to be
used to allow users to put much more information into the profile
than their operating system might allow in a file name. Remember that
the ICC standard is supposed to be platform agnostic. Unfortunately
this is a great place for confusion. A user will typically change a
profile name in the Finder or whatever tool they have on their
platform and then find that the name that appears in most menus
remains unchanged. I agree with the decision of Adobe and other
application vendors to display the more descriptive internal name in
menus but I see where confusion can occur. In our profile toolset
ColorThink, you can search for all profiles that have differing
internal vs external names and rename either at will. You can also
use a free Applescript droplet called rename profile to change the
internal name of the profile to be the same as the external.
3. I also added Digital Swatchbook to the mix this week. After setting
it up and calibrating it, I notice that even though my 100% black chip
in the 21-step wedge LOOKS totally black, the reading from the
spectrophometer reads out at about 31/32/35 RGB. I would think it would
be definitely 0/0/0
Well, first of all, ignore RGB. You should really be looking at the
Lab value the swatchbook returns you. The L value of the black may
range from 1-5 up to 20-30. If you see it as really black and the
spectro measures it as above ten, then you may have a surface
reflectance problem. There are several ways spectros can be fooled
into giving incorrect measurements.
Regards,
Steve Upton
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