doesn’t happen here either
really?? wow..
well this just makes it a lot harder to figure out what the problem is..
any suggestions on what it could be?
I can’t reproduce what you’re describing. This is what I see:
Create new CMYK file. Fill with white (0/0/0/0).
Convert to grayscale (Image>Mode>Grayscale).
Check with info palette – value is 0%.
Convert back to CMYK – value is still 0/0/0/0.
I’m confused by your statement that the 1% black seems to be coming from the magenta channel. What is this specualtion based on? When you created the CMYK file, M = 0%. Then, when you convert to grayscale and K = 1%, there is no magenta channel. Confusing.
color management settings
What are your color settings? (Edit>Color Settings)
color engine choice and rendering intents will do this.
okay.. i made some screen shots..
this is my cmyk image with the eyedropper over the image., you can see the info palatte shows all zero’s for color values
and then converted to grayscale
as for my color management settings, CMYK i have set for US Web Coated v2 and for grayscale i have dot gain 10%. what do you all recommend. most of what i do is for print work, so those settings seemed to make the most sense.
Give us a screen shot of your color settings
You are not using the Apple ColorSync "Engine" are you?
so the apple colorsync engine might be it?
and ichanged the grayscale to gamma 1.8 to see what happened.. but it’s normally set to dot gain 10%
so the apple colorsync engine might be it? >
Very likely!
NEVER use the ColorSync engine nor the Apple Color Picker both are problematic.
changed it to adobe (ACE) and the 1% doesn’t show up anymore
so thanks 🙂
as for my other color settings, if there’s one you guys recommend over another, i’m all ears.
don’t use your monitor profile as your working space for RGB
I’d set everything to Preserve Embedded Profiles, not to convert to your working space or off in the case of RGB. Unless you really understand what you’re doing, you’re going to run into problems here.
excellent. this helps a lot.. and i’ll be passing it on to everyone else i know that has had a similar issue.
I’m sorry but I can’t imagine that any color settings would convert pure white to anything but white.
I set my settings to the OP, except for setting his custom monitor profile to his working RGB and I did not see 1% black.
And if I did have his monitor profile how how would the RGB working space impact converting from CMYK to Grayscale.
So the conclusion is not that the color engine is doing it, but the monitor profile.
No, it can be a combination of things including CS 1 vs. CS 2.
changing the color engine and only the color engine eliminated the problem. i don’t know how or why that works, but it does.
I just opened a new CMYK file, filled it with "50% gray", set the secondary readout of the info palette to grayscale, and went into color settings and scrolled from one RGB space to the next, and did not see the resulting grayscale value change in the least.
Give me something repeatable.
John, just shoot yourself in the head. That will be repeatable – but only once.
you think you can get two rounds off before you hit the floor?
;o)
I suppose the angle of the gun might play into it, but seriously, if using the Apple CM did this wouldn’t it do it for all?
Did you try it Mike? If so what settings?
Can ANYONE reproduce this?
Yes. If have the odd color settings the OP posted. (Monitor RGB working space., 1.8 gray, Apple CMM conversion engine.) I’m using CS at here on a Powerbook.
Though… I thought I tried these settings at work on CS2 on G5, but couldn’t reproduce.
Still puzzled why changing the RGB working space would have an effect.
Still puzzled why changing the RGB working space would have an effect.
Because a monitor space is not a working space, also he was using the Apple color engine instead of the Adobe engine.
I get the Apple engine part.
But if you create a new CMYK file, then convert to Grayscale to see the problem…. how does the RGB working space come into play?
Apple CMM is seriously messed up when it comes to integrating with PS. You should see the banding that develops on the fly in a black to white gradient created in AdobeRGB then switching between ACE and Apple in Color Settings.
It does it in OS 9.2.2, PS 7.01. Wondering if it continues in CS2 and OS X.
I tried to reproduce it on a G5 iMac using CS1, and was unable to.
Though I’m not half the color geek that MO is, I would argue that the RGB working space has no effect on CMYK>Grayscale conversions.
Charles: when you are able to reproduce the problem, and change only the RGB working space to Adobe RGB does the problem go away?
PS: I just saw MOs #20 post which he had edited some time after I saw it… And that makes sense, that it is a combination of things. The key part is not to use the Apple Colorsync engine. Period.
Charles: when you are able to reproduce the problem, and change only the RGB working space to Adobe RGB does the problem go away?
No. The color engine choice seems to be the causal factor. But at this level of CM I have no idea what causes what.
Not really.
All I see is that the Apple CMM is a factor, probably a required factor, but there is another unknown factor that triggers it, and it isn’t the RGB working space.
It’s called changes in the application.
Bye John – it was a pleasure knowing you.
mo
