ABW profiles aren't linearized what changed?
2011-12-17 by CelluloidPhotography
Ok this is driving me crazy here, I'm past the point of caring about asking a stupid question. I'm running an 11880 and until now I really haven't used ABW mode all that much, the majority of my b/w work has been done on a K7 9600. I have built a few ABW profiles here and there, and they've worked reasonably well, so I haven't given it much thought. However, after recently upgrading to snow leopard, something's amiss in ABW town. I use Photoshop CS5 for image editing, but kept CS3 just for this reason. However, when I tried my old settings for creating an ABW profile, it was way off. I downloaded Jon Cone's linearization checker, and sure enough, I'm definitely not linear. It makes me wonder if my ABW profiles ever were... I guess I foolishly assumed that as long as I was getting decent results, they must be. Needless to say, I'm excited to have found a way to precisely confirm linearization, the numbers don't lie! Don't ask why I didn't just make a chart in excel before... So I've been messing around with this all week, and I'm to the point of analysis paralysis- I've tried every combination of workaround and setting I could think of, and I still can't get one ABW profile that falls within the acceptable range for a proper linearization. I'm sure I'm missing something stupid, so I figured it's time to run this by some other people. Here's what I'm doing: I kept the most recent printer driver that still allowed you to use profiles with ABW mode. I'm running snow leopard in 64-bit with CS3 & CS5 installed. Out of CS3 I print the 21x4 chart that comes with QTR, leaving it untagged. I set the printer to no color management, neutral, dark. I read the results with measuretool and drop the generated file on the create icc app. At this point I load the LAB values from the "out" file into Jon's linearization checker just to see where I am. And maybe I'm getting screwed up from QTR here, but I don't expect it to be perfect at this point. I thought the true test was to print another chart, this time with the profile. I leave it untagged still, and send it with the new profile, using perceptual. I drop the readings from the new chart onto the linearize app, so it can average the 4 measurements, then I load the LAB values from the out file into the linearization checker. The results show a nice smooth curve, but it's way too light. After trying every variable with this method that I could think of, I started trying some of the workarounds for CS4/5, even though you're not supposed to need them for CS3. Some of those results were closer to linear, but always looked like one S curve or another. So am I making some simple mistake that's throwing the whole thing off? Am I misunderstanding this tool for checking linearization? Is the new OS/software combination working against me? Or is it not even possible to get a perfectly linear ABW profile without using an .acv? My poor old spectroscan has had a serious workout this week Any input would be most appreciated! Thanks