RE: Printing of photography
RE: Printing of photography
- Subject: RE: Printing of photography
- From: "Robert Rock" <email@hidden>
- Date: Mon, 20 Dec 2010 14:28:11 -0500
- Organization: P. Chan & Edward, Inc.
Personally, I wouldn't make any tweaks or corrections until AFTER the first
proof. The pre-press or printer's job is to print a proof showing accurate
reproduction of the chart/strip. If this is done and the color of the
artwork is still not right, even though the test strips are right on, then I
would tweak from there. I have found that in MOST situations, if the test
strip/target appearing in the image is reproduced accurately, the color of
the artwork or subject will also be very close indeed. Of course if the
artwork contains special pigments or substrates which make it difficult or
impossible to reproduce, then certainly another method of color
control/correction must be investigated. But again, for MOST end use (museum
catalogs, artbooks, etc...), matching the test strip is usually close enough
in our experience. We have been printing calendars, posters, artbooks,
etc...for a number of years for many publishers, and only in rare instances
does this procedure not work (for example, some of the Klimt paintings
which have lots of metallic gold, or in some contemporary works containing
vibrant pigments, etc...).
We can go on nit-picking about this, but for most commercial end uses, this
serves as an acceptable starting point.
Bob
-----Original Message-----
From: David Ramsey [mailto:email@hidden]
Sent: Monday, December 20, 2010 12:05 PM
To: email@hidden; ColorSync Users Mailing List
Subject: Re: Printing of photography
So, If I do include a color target and I, for example, move the blues
towards purple is this not going to throw whomever is looking at he image
off. It seems that if the printer is trying to "match" a target then he/she
will be incorrectly "correcting" the artwork. This leads me to this
question, If I am in a color managed workflow (my responsibility to be
accurate) and I send you or whomever an RGB
ADOBE98 file tagged as such and you open the file on your color managed
system (your responsibility to be accurate) would you not see the exact same
thing as I do? And likewise, should the printer see the same?
I am not comfortable sending special instructions downstream with a file.
Who knows where or with who it is going to land.
David Ramsey
On Dec 20, 2010, at 11:40 AM, Robert Rock wrote:
> I could not disagree more with Ken's suggestion that NO color target
> should be used when photographing artwork. In my opinion, there
> absolutely SHOULD be some known reference included in the photograph,
> perhaps a Macbeth ColorChecker, or even an old Kodak Q-13 chart.
> Assuming that the image will be reproduced from this digital capture
> later on, what would pre- press or the printer use for a reference?
> You have to assume that they have never seen the image and have no
> idea what it should look like. Instead of wasting everyone's time
> sending proofs back and forth, it at least gives them a visual
> reference that they are in the ballpark when proofing. Ken is right
> that there are some issues that may affect color accuracy (metamerism,
> etc...), but there still needs to be a base from which to start. The
> printer or pre-press person needs to have some reference as to what
> the image should look like. If there are no color bars or reference
> data in the image, the first thing the printer will tell you before
> proofing is that 'he has no idea what the image should look like and
> that all he did was output to proof...'. After proofing, if further
> color tweaking and adjustments are desired to more accurately match
> the original, then have at it.
> There most
> certainly WILL be the need for tweaking of the color and/or tonal
> contrast, if not for reasons that Ken mentioned, perhaps because of
> the inks used, paper, type of dot pattern, etc...But again, I believe
> that there should be a starting point or reference for the printer,
> and that should be dictated by the use of a known color reference
> included in the capture. One can agree or disagree with this, but
> bottom line is that 1) Many printers WILL require it, and 2) What harm
> does it do to include it in the capture? You can always give the
> instructions to ignore the patch if you so desire.
>
> Bob Rock
>
> -----Original Message-----
> From: colorsync-users-bounces+rock=email@hidden
> [mailto:colorsync-users-bounces+rock=email@hidden]
> On Behalf
> Of Ken Fleisher
> Sent: Monday, December 20, 2010 10:10 AM
> To: David Ramsey; ColorSync Users Mailing List
> Subject: Re: Printing of photography
>
> On Mon, Dec 20, 2010 at 9:18 AM, David Ramsey
> <email@hidden> wrote:
>>
>> 2 questions;
>>
>> 1) I am getting ready to photograph some works on paper for a museum
>> and I was asked about including "color bars" in the photos. Because
>> of the nature of the materials used in these works I have to adjust
>> specific colors as we shoot (Color managed workflow and calibrated
>> display). Colors are adjusted individually, for example, purples may
>> go
> towards blue reds towards magenta.
>> So if I place color bars in the frame and will this not create havoc
>> down the line since I am moving individual colors around? Also which
>> color bars should I use if they are to be included?
>
> I do not recommend including a color target when photographing artwork
> for reproduction for the following reasons:
>
> 1. The camera's spectral sensitivities are different from a human's.
> Because of this, the differences in the material on a color target and
> the artwork can result in "observer" metamerism. (i.e. getting the
> color of the target correct does not imply that the color of the
> artwork is
> correct.)
>
> 2. Because of observer metamerism, the color target is not a reliable
> indicator of an accurate color capture of the artwork.
>
> 3. As you describe, if you make color edits to the image to make the
> artwork correct, the colors on the target can no longer be used as a
> reference of any sort, since those colors will necessarily be moved as
> well.
>
> 4. Trying to match the colorimetry of target colors all the way to the
> printed page is an incorrect goal anyhow. If you do this, your
> reproductions might be colorimetrically correct (if you are lucky),
> but will likely appear dark and flat. Instead, you must try to match
> the color appearance, which usually involves opening up the image and
> increasing contrast (many perceptual rendering intents achieve this
> for us when printing, but not so for image capture).
>
> I recently spoke on this very topic at "Currentl Practices in Fine Art
> Reproduction" which was a symposium at the Rochester Institute of
> Technology. You can view a video of the talk at
> <http://tinyurl.com/3x5rv6v>. This was a panel discussion on target-
> based workflows and my part begins at 29 minutes into the video
> (though you may find the entire panel interesting.).
>
> Ken Fleisher
> Color Scientist
> National Gallery of Art, Washington, D.C.
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