Luminous Landscape Forum

Raw & Post Processing, Printing => Colour Management => Topic started by: dubscura on February 08, 2021, 03:49:57 pm

Title: Comparing Custom Profiles to Manufacturers
Post by: dubscura on February 08, 2021, 03:49:57 pm
Hello all,

Comparing the 3D graphical representation of manufacturer profiles from Canson, Hahnemuhle and Moab to the ones I with an i1pro in ColorSync, the manufacturers profiles all begin where the two black lines cross.  The gamut blobs from profiles I've made hover over the black line crossing point.  Unlike the manufacturer profiles which look like they are funneling out from the two black lines, mine don't touch the black at all.  Is that normal behavior?  Trying to figure out why this discrepancy is consistently occurring.   

Thanks!
Title: Re: Comparing Custom Profiles to Manufacturers
Post by: digitaldog on February 08, 2021, 04:03:50 pm
Examining a gamut plot alone isn't at all telling of profile quality. Would you be happy with a larger color gamut that also had poor gray balance?
The perceptual table in all profiles is proprietary meaning all profilers can create the table as the manufacturer feels is the 'best' rendering for their customers. Like E6 film. I have no idea why, in the film days, Agfa though it's rendering was so great. I found it awful, preferred Velvia. The point is, this is subjective.
You want to test profile quality? Make prints with color reference images. Testing all the rendering intents.
This might help:

Not all ICC profiles are created equally

In this 23 minute video, I'll cover:
The basic anatomy of ICC Profiles
Why there are differences in profile quality and color rendering
How to evaluate an ICC output profile
Examples of good and not so good canned profiles and custom profiles on actual printed output.

High resolution: http://digitaldog.net/files/Not_All_Profiles_are_created_equally.mp4
Low resolution (YouTube): https://www.youtube.com/watch?v=TNdR_tIFMME&feature=youtu.be


Oh and the CS utility really isn't an ideal tool for gamut viewing:
http://www.colorwiki.com/wiki/Color_Management_Myths_26-28#Myth_26