RE: Light Generation-clarification on how to prepare
RE: Light Generation-clarification on how to prepare
- Subject: RE: Light Generation-clarification on how to prepare
- From: Rick Gordon <email@hidden>
- Date: Thu, 22 Jul 2004 11:39:18 -0700
I'll leave answers regarding the Chromix profile or the UCA to others, but would comment that using a heavier black generation could be insurance against color casting of the neutral gray images. For black images, a strongly boosted, contrasty, and significantly sharpened black channel with an overall low total ink limit comes recommended by Dan Margulis (quoted below):
At 6:20 PM -0400 7/16/04, email@hidden wrote to the Color Theory List:
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Generally speaking, the darker the shadows are, the snappier the picture is. So, ordinarily we want to have values in all four channels as high as possible consistent with retention of some detail and with the ink limit.
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The screaming exception is when objects that can be described as being "black", such as the ones mentioned by Stephen above, are critical to the picture. In RGB, shadow detail is found in all channels, but in CMYK, it almost all migrates to the black channel and the CMY are quite blurry. In such critical-shadow-detail images, we have to have the snappiest, sharpest, and best possible black channel. To ensure maximum contrast in the black channel, we often hike the maximum ink into the 90% range, considerably higher than normal.
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In that kind of image, and that kind of image only, heavy CMY in the shadows is a hindrance, not a help, because it just dumps extra shapeless ink on top of an excellent black channel. So, it's appropriate to go Selective Color>Blacks and reduce CMY. Our total ink in this kind of picture should be around 225%. It sounds too low, but we get significantly better quality that way.
Rick Gordon
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On 7/22/04 at 9:50 AM -0700, Doug Walker wrote in a message entitled
"Light Generation-clarification on how to prepare":
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I am wondering what the real skinny is on Light Generation.
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My printer at a bucket shop/Web press wants me to use Light Generation which helps them adjust on the press on my next CMYK delivery.
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I have been reading here that the Medium or Heavy will keep the image more pure. US Web Coated SWOP v2 is Medium as a default already right? So I am at the proverbial crossroads once again. We are essentially printing a bunch of neutral grey and black metal product images in this application at this printer.
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If I understand correctly, And in keeping with this, I have also been told that if you invoke Custom CMYK dialog box found in Photoshop>Color Settings to alter things such as TAC, or select Light Generation, it is a low grade solution as it builds a profile that is comprised of very few points, is small, and not very accurate. Yes? No? This would include adjustments to the UCA 5%. Is this a generally accepted fact?
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I still see this touted in todays digital magazines as a proper method of tailoring CMYK output. Just got one in the past couple months.
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Are they disseminating old marginal information?
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Wouldn't one be best served by simply doing a better job of adjusting or preparing an image in RGB, with Soft Proof side by side with regards to forcing the proper end points and pulling off some heaviness via curve adjustments so that the numbers needed for TAC, etc.. are in place before AND THEN CONVERT to the destined US Web SWOP Coated v2 profile.
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I am nervous about mucking with the old Legacy PS4 CMYK SWOP Engine just to force a Light Generation.
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Is the Chromix's Light Generation 280 profile I keep hearing everyone talk about simply a US Web SWOP Coated v2 profile with a Light Generation and 280TAC as opposed to standard Medium and 300?
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If so, it would seem then that a solution like that would be much safer than invoking the ol Legacy PS4 engine.
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Thoughts?
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___________________________________________________
RICK GORDON
EMERALD VALLEY GRAPHICS AND CONSULTING
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WWW:
http://www.shelterpub.com
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