Tuesday, 16 May 2017

Paper to Pixel to Paper Again: Part 16

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A guide to creating the best looking line art in print in the new digital print world

Part 16
Working with "Bad" Negatives, A


This is the sixteenth installment of Paper to Pixel to Paper Again, a series that explains (in an overly thorough manner) the how-to's of preparing line art (and later in the series, color art!) for print.

And as always, if you have any questions, please let me know in the comments!

In the previous installment, we wrote a Photoshop Action for adjusting and sharpening our scans of production negatives. That previous installment made the assumption that the photography on those pages was fairly uniform, and mostly of a high quality.

Well, that won't always be the case. But with careful attention at the early adjustment stages, we can wring an extraordinary amount of detail from even poorly photographed or developed negatives, representing a significant improvement over any previous printings from those photo elements.

Because these are really case-by-case kinds of problems, I'll present specific examples and elaborate on how the issues were dealt with.

Bad negatives, part one— Cerebus Issue 26

Issue 26 of Cerebus represented several changes in the book. It was Dave's first attempt at a sustained continuous story that would rise, evolve, and then resolve itself at a predetermined point. It was the first issue printed by the new printer that would end up having a sustained relationship with the book, Preney Print and Litho. And, perhaps owing to their newness on the job, it represents an early low point in the photography of the book.

These photo negatives were shot with stat cameras that were fitted with high-contrast film and shot with high-contrast filters, in order to produce an image, and eventually, a printing plate, that was binary—either an inked surface, or an uninked surface. Occasionally, though, through either a poorly adjusted contrast filter, or even a poor quality of film, the negatives either don't have the contrast required, or have that contrast point placed too dark on the spectrum of what information the camera is picking up. When this happened, incidental unerased pencil, smeared pencil schmutz, or even just staining on the art board was brought up into the visible range of the exposure, and consequently clogs the image with unintended "information."  

As you can see in the above detail, this problem also affects the China white-produced white-on-black effects, which are hit and miss anyway even in the best of circumstances. 

It's no surprise that this problem affected the majority of the issue, though which pages were most adversely effected is mostly due to the randomness of where there happened to be pencil schmutz to bring up. The below pages was particularly affected.

But in many cases like this, extreme digital adjustment allows us to separate the intended information from the unintended. 

Hit Ctrl-L to bring up the Levels command, and move the Gamma control (the Mid arrow) to the left, changing the overall exposure of the page. Unlike adjusting a normal negative, where we might bring this arrow over only far enough to get the desired exposure of the page. this time we'll move the arrow until the schmutz disappears, or almost so. Check out the example above.

Now instead of running our negative Action, we're going to do the following manually—

a. resize to the desired size (you can even play back just this line of your previous Action)
b. make a copy of the layer, as normal, and name it "Sharpened" (or play back this line of your previous Action)
c. make a Threshold adjustment layer ( (or play back this line of your previous Action)

Now we'll sharpen and adjust manually, in an attempt to keep all the good information while eliminating the bad.

Zoom in on an area where the schmutz is particularly bad, ideally also an area that has fine information of another type nearby. Now bring up the Unsharp Mask dialogue. We're going to look for the right Threshold where our sharpening will only affect the desired areas and not the schmutz, so temporarily bring up your Amount to 500 percent. (The Radius should be at or just above 1 px, as normal).

After this, bring up the Levels command again and this time move the White point to the left, knocking out the lightest end of the image. Then try sharpening again, and knocking out the white again. Depending on if there are any other oddities for the page or for your scan, or any other "weak" information you might want to selectively sharpen, this could be all you need, or you might need some spot adjustment in some areas. You can also try individually adjusting just a selection of the page in very extreme cases. In this case, that wasn't necessary!

The result, prior to cleanup—

...continued next week!

Click here to download the scan used for this week's example. Please note—this scan is not to the specifications noted in previous installments, as it was scanned prior to my coming on to the project.

Sean Michael Robinson is a writer, artist, and musician. See more at LivingtheLine.com.


andrew said...

these are always a great read. thank you!

Sean R said...

Thanks for reading, Andrew! Very glad it was helpful.