If I werent holding the target
sample print in my hand I wouldnt have had the confidence to ask this question.
I overheard a technician suggest
to a student who was printing greyscale on an Epson 7500, to send the file same as source and
print with black ink only to get the best results Of course the technician was
focusing on the colour inconsistency problem with pigmented inks, we generally
refer to as metamerism
I decided to be prudent and
actually test the theory before I bloated out about how preposterous it would be
to send a file in its
workspace, with a dynamic
range of L*0 to L*100, without any conversion, compensation or compression to a
printer with a maximum shadow at about L*14.
I sent a target which is basically
a series of pairs of black patches with values of L*1 difference that I use to
discern maximum shadow and minimum highlight. For example the first patch is L*1
in L*0, the second L*2 in L*1 etc.
When I send this target using relative with no black point compensation
to the 7500, the first line appears in the L*14- L*15 patch. Using perceptual, depending on the
profile, the line appears in the first or the second patch.
The Greyscale 2.2 to same as
source test print produced lines in every patch.
In all other circumstances,
converting a file to its output profile en route as Photshop allows us to
do, or actually converting the file
before hand and using the same as source option, produces identical
results. To me this means the same
as source option is performing exactly as it is meant to and leaving the file
as is, transferring the data without any modification.
So how, or what, is translating
L*0 to L*14? and subsequently compressing all the other values up the
curve????
Can any one help me understand
what is happening?
Eugene