• Global community
    • Language:
      • Deutsch
      • English
      • Español
      • Français
      • Português
  • 日本語コミュニティ
    Dedicated community for Japanese speakers
  • 한국 커뮤니티
    Dedicated community for Korean speakers
Exit Search
0

Convert to CMYK Profile in Photoshop producing different results on Windows and Mac

Explorer ,
Feb 08, 2023 Feb 08, 2023

Copy link to clipboard

Copied

Hi there, I've tried using "convert to profile" on an untagged RGB image from Shutterstock or similar into PSO Coated v3, and noticed that the PC produced noticeably different results (much worse / oversaturated) to the Mac. At first I thought that was down to the screen being rubbish, but the CMYK histograms are really noticeably different too – surely they should be identical if they're using the exact same profile for conversion, right? The ICC profile used is, unless I've made some stupid mistake, the same date, and exactly the same number of bytes. Has anyone else seen this behaviour? Is it something to do with the RGB profile of the screens, and Photoshop is trying to copy what the (rubbish) screen is displaying into CMYK? I'm only led to that idea because the converted and unconverted images look identical on both PC and Mac screens (as they should, more or less), but I'd expected the same inputs to have the same histogram output, right?

 

See attached (Mac histogram + image on the left, PC on the right). 

 

 

TOPICS
macOS , Windows

Views

352

Translate

Translate

Report

Report
Community guidelines
Be kind and respectful, give credit to the original source of content, and search for duplicates before posting. Learn more
community guidelines

correct answers 1 Correct answer

Community Expert , Feb 08, 2023 Feb 08, 2023

As Stephen says, a conversion implies a source as well as a destination. But you have an undefined source.

 

You need to start by defining the source, and you do that by assigning an RGB profile to the original. You just have to pick the one that looks right, try sRGB, Adobe RGB, Image P3. Then you can convert to PSO Coated, and then they will be identical.

 

If you receive untagged files you need to assign a profile immediately! Don't wait.

Votes

Translate

Translate
Community Expert ,
Feb 08, 2023 Feb 08, 2023

Copy link to clipboard

Copied

@ukzembla 

 

There has to be a source, as well as a destination (in addition there are conversion options such as rendering intents, BPC and CMM).

 

It sounds like the assumed (working RGB) source profile is different on both systems.

Votes

Translate

Translate

Report

Report
Community guidelines
Be kind and respectful, give credit to the original source of content, and search for duplicates before posting. Learn more
community guidelines
Community Expert ,
Feb 08, 2023 Feb 08, 2023

Copy link to clipboard

Copied

As Stephen says, a conversion implies a source as well as a destination. But you have an undefined source.

 

You need to start by defining the source, and you do that by assigning an RGB profile to the original. You just have to pick the one that looks right, try sRGB, Adobe RGB, Image P3. Then you can convert to PSO Coated, and then they will be identical.

 

If you receive untagged files you need to assign a profile immediately! Don't wait.

Votes

Translate

Translate

Report

Report
Community guidelines
Be kind and respectful, give credit to the original source of content, and search for duplicates before posting. Learn more
community guidelines
Community Expert ,
Feb 09, 2023 Feb 09, 2023

Copy link to clipboard

Copied

quote

As Stephen says, a conversion implies a source as well as a destination. But you have an undefined source.

 

Agreed! I call this an assumed source, as that is what working RGB is for an untagged/undefined file.

 

quote

You need to start by defining the source, and you do that by assigning an RGB profile to the original. You just have to pick the one that looks right, try sRGB, Adobe RGB, Image P3. 

 

If you receive untagged files you need to assign a profile immediately! Don't wait.


By @D Fosse

 

I facetiously call this "RGB ICC Profile Roulette", however, it isn't just random or luck, one evaluates the image visually and or with the info panel providing an informed basis for the decision to select a profile. 

 

https://prepression.blogspot.com/2014/06/rgb-icc-profile-roulette.html

Votes

Translate

Translate

Report

Report
Community guidelines
Be kind and respectful, give credit to the original source of content, and search for duplicates before posting. Learn more
community guidelines
Community Expert ,
Feb 16, 2023 Feb 16, 2023

Copy link to clipboard

Copied

LATEST

Your screen colourpace is not used in the conversion to CMYK

Stephen and D Fosse are right, receiving an untagged image means that the system has to make an assumption, maybe your Win and Mac machines are set up differently (Photoshop Color Settings) the default RGB working colour space there is used as a source for the conversion (and viewing of) untagged images. 

 

By the way, why the hell are the library selling untagged images! It's resulting in Russian roulette.

You'll need to open the image on a calibrated screen and "try" assigning different RGB profiles until the image "looks " right. See what we mean about roulette! Then save with the profile embedded and try it on both machines.

 

I hope this helps
neil barstow, colourmanagement net - adobe forum volunteer - co-author: 'getting colour right'
google me "neil barstow colourmanagement" for lots of free articles on colour management

 

Votes

Translate

Translate

Report

Report
Community guidelines
Be kind and respectful, give credit to the original source of content, and search for duplicates before posting. Learn more
community guidelines