Printing Bug: subtle color mottling appears in light neutral area of large (not small) print - ruins print.
LR 5.2 (also 5.3RC)
I recently upgraded from LR4 to LR5. Last week I printed a large (43"x35") art print for a client on my Canon ipf8100 44" printer. I had resized the image file to full dimension and 300 dpi and added a white border in Photoshop CS6 prior to printing. This print is an RGB seascape in fog, with the upper portion of the image being a neutral grey that shades from over 50% to about 10% grey.
Upon closely examining the print I discovered a subtle color mottling in the light grey areas of the print, unfortunately not so subtle as to be salable. This mottling is not present in the source image file. The artifacts are macroscopic (1/4" to 1"), not simply digital color noise.
A letter sized crop from the 300 dpi image file does NOT showing the mottling when from Lightroom with identical settings (except print size, of course).
I was able to make a clean print of the image printing from Photoshop CS6 and using the same Canon print driver.
I had printed this file before at smaller size (18x24) using LR4 without noticing any issue.
This issue is reproducible only at the printer. The mottling does not appear in a .jpg or .pdf generated thru the LR print module.
The LR print settings were:
Single Image/Contact Sheet
print resolution 300 dpi
Color managed workflow, Relative rendering
Turning off sharpening made no difference. 16 bit output made no difference.
Using LR 5.3RC made no difference.
Using the original resolution camera image (vs resize in PS CS6) made no difference.
My hardware is:
iMac (iMac 5,1)
3 GB ram
OS X 10.7.5
Canon print driver ver 2.63
Since I could not capture the problem in a jpg or pdf from the print module, I have scanned a corner of the printout to show the problem. I have also contrast enhanced a copy of the image to more clearly delineate the mottling. I am attaching the file at the end of this note.
[Side note: I cannot make the bug report form at Photoshop.com respond. I paste in the above, click "Continue" and the button switches to "Continue…" . I click that and no dialog box appears. Nothing happens except my blood pressure rises. Same result current Firefox or Safari. I am logged in.]
I custom profile my papers using an i1 and xrite Match. The successful full sized print from photoshop used the same profile as the flawed print from Lightroom—as did the good test print from Lightroom of a letter sized crop of the problem area.
The Calculated Image LLC
Fine Art Digital Printing For Everyone
520 4th St E
208 928 7083