colorsync-users

Download

colorsync-users@lists.apple.com

December 2014

24 participants
12 discussions

Re: Softproof puzzle
by Nagy Péter 01 Dec '14

01 Dec '14

Hi Peter, I’ sure dithering does matter in your case as Matthew already pointed out. In the dark shadows it can make things easier after a proper conversion, since the 8 bit resolution per channel isn’t enough to handle such images. You can simulate the effect by applying a very subtle noise (1-2 percent). In our practice we always handle and edit grayscale or near-grayscale images in 16 bit, to have a better softproof (and final art). Regards, Peter Colorcom

1 0

Softproof puzzle
by Peter Miles 01 Dec '14

01 Dec '14

Hi List members I don't understand something I have been seeing when soft proofing our staffs black and white images. When printing on hahnemuhle PhotoRag 308 paper on our Epson9900 printer I use a custom profile to soft-proof the image before printing. The PhotoRag 308 paper profile is a CMYK profile and built in i1Profiler. I use a colorburst RIP. I have noticed that the soft-proof of our staffs B&W images show posterizing in the deep shadows, when the images they supply are in the Adobe RGB1998 colorspace. But the same image, in Gray Gamma 2.2 space does not soft-proof with the posterizing in the shadows. My understanding is that the gray axis of Adobe RGB1998 IS gray gamma 2.2. So why the difference in the soft proof when the a source file is Adobe RGB1998 vs Gray Gamma 2.2? NOTE: When I use Photoshop to actually convert the RGB versions of the image to "hahnemuhle PhotoRag 308" CMYK color space, there is no posterizing visible in the shadows of the converted file. So it just appears to be a soft proofing thing, but only with 'RGB' colorspace versions of the B&W images. Your help with clarifying why this happens would be appreciated. Thanks Peter Miles

5 6