Color Checker

[Philipp_22]

Hey Everybody

I have a few questions considering working with a Color checker.

I just shot 15 Reproductions of Oil-Paintings and used a 15year old original Gretag Macbeth (GMB) Colorchecker.
(As I just figured out, Xrite purchased GMB around 2010.)

- My first question:
Does anybody know if the values from GMB are the same as the ones from the modern Xrite Colorchecker?
I did assume that, since all the colours have the exact same name, but I'm suddenly not sure anymore...


Now my main problem:

With a reference-checker-photo of the Oil-Painting shooting, I created an ColorProfile in Adobe Light Room.

If I now switch on the "Develop" Site to Soft Proof (on the very bottom) I'm able to read the RGB values.
Unfortunately those are quite different as the colorimetric values I found on the Xrite Photo site.

For Example red:
Lightroom vales R 208 G 0 B 53
Xrite Chart values: R 175 G 54 B 60

Has anyone any support for me?

THX a lot for your thoughts!!!

 

[Box Brownie]

Hi and welcome to TP

I cannot help with the specifics of your question.

However, one thing I have always understand in regard to colour reference materials is that the moment you start to use them they will change due to environmental exposure.

For example, in a past job we used to occasionally need to refer to our Pantone reference books. We felt obliged to buy a new set and then realised that even though the old (approx 10 years old) set was always kept in a dark store cupboard when not needed it had faded/changed in comparison to the brand new books!

Therefore IMO where you need colour accuracy such an old reference that you are using is long beyond its "use by date".