Near black changes after 'Profile Only'

[Steve Smith]

Hi Florian.

I noticed that after doing a ‘Profile Only’ my near-black and/or the black point seems to change. (gets brighter)… I thought that ‘profiling only’ leaves the calibration alone.

Also, why is there a choice to select both ‘Embed calibration’ and ‘use linear calibration’ at the same time? Doesn’t make sense to me that both boxes can be checked at the same time as these two choices are mutually exclusive… Is there a scenario where both might be checked at the same time?  Either you’re using the existing calibration or your not.  – (‘Not’ meaning that it’s linear).

Thanks for any clarification you might provide.

• This topic was modified 6 years ago by Steve Smith.

[Florian Höch]

I thought that ‘profiling only’ leaves the calibration alone.

It does.

Also, why is there a choice to select both ‘Embed calibration’ and ‘use linear calibration’ at the same time? Doesn’t make sense to me that both boxes can be checked at the same time as these two choices are mutually exclusive

They are not exclusive. The matrix is:

• ‘Embed calibration’ + ‘use linear calibration’ checked: Linear calibration used and embedded in profile.
• ‘Embed calibration’ checked, ‘use linear calibration’ unchecked: Current calibration used and embedded in profile.
• ‘Embed calibration’ unchecked, ‘use linear calibration’ automatically checked: Linear calibration used, but not embedded in profile (implicit linear calibration will be loaded from profile).

[Steve Smith]

Any thoughts as to why the near-blacks seem to change when toggling between profile being applied\not applied?

-Using ‘profile only’ (No calibration present in profile).

Thanks.

[Florian Höch]

Any thoughts as to why the near-blacks seem to change when toggling between profile being applied\not applied?

In color managed applications, this is to be expected, unless your monitor follows exactly the tone response of the respective source profile already.

[Steve Smith]

Well, maybe I’m confused about how this works then… You say that the color profile leaves the calibration alone… But then you agree that my gamma curve changes (near blacks distrubution of lumanance) when a profile is utilized by a color managed program.

Can’t the colors be corrected (profilling) without changing the gamma curve?

Can you please explain.

Thanks.

• This reply was modified 6 years ago by Steve Smith.

[Florian Höch]

Sure. Say the source profile is sRGB, which has an overall response close to a pure power curve with a gamma of 2.2 – but not near black. sRGB employs a linear segment near black, so gamma is lower there. If your display has a higher gamma near black, then of course to get the sRGB response near black, the near black display response needs to be lightened slightly to match the correct output luminances dictated by sRGB.

[Florian Höch]

Can’t the colors be corrected (profilling) without changing the gamma curve?

Color does not exist without the luminance component.

[Author]

Posts