Camera profile adjustments

[mdijb]

I recently watched a video where adjustments were made to color using the Saturation sliders under the Camera Profile tab in LR.  The results have been very pleasing and often better that moving VIbrance/SAturation sliders in the BAsic panel.  The Blue PRimary-> sat slider often gives dramatic results.

I like the results but really do not understand what is happening here--Can any one explain?

MDIJB

[AlterEgo]

I like the results but really do not understand what is happening here--Can any one explain?

they adjust "forward matrices" in dcp profiles...

[mdijb]

Please explain what these are.

Thanks

[AlterEgo]

Please explain what these are.

Thanks

http://wwwimages.adobe.com/content/dam/Adobe/en/products/photoshop/pdfs/dng_spec_1.4.0.0.pdf, section 6

[mdijb]

Tried your reference.  Highly technical and reads like greek to me.

Thanks any way

MDIJB

[George Marinos]

Can anybody say more on this interesting subject ?! Please....

[AlterEgo]

Can anybody say more on this interesting subject ?! Please....

what is to share ? forward matrix tag(s) is/are a part of a color transform (pre exposure compensation done in ACR/LR UI)... sliders available in UI for ACR/LR will allow you to modify that matrix part so that basically you distort the color transform guided by a DCP camera profile ( that matrix part works together with HueSatMap LUT(s) and together with WB guided by colormatrix tag(s) - before exposure corrections ) to make certain colors more saturated/less saturated or change hues on a profile level... for example if you have some colors that you DCP profile move outside of your desired gamut (make sure that it is not a WB issue) then you can forcefully and crudely desaturate ... not that it is the right approach though.... of you can just get creative with distortions.

[digitaldog]

Tried your reference.  Highly technical and reads like greek to me.

Best to ignore that stuff, just use the slider to produce a rendering you prefer. There's a huge amount of technical 'stuff' happening behind the scenes, with every slider that you'll never find a resource to explain outside a willing Adobe engineer. As such, if you found a video that shows the use of a slider, anywhere, that produces a result you like, use it when it's appropriate and enjoy. 

[Peter_DL]

From my files:

Quote (Bruce Fraser, 2005, Adobe Camera Raw Forum) >> For each supported camera, Thomas Knoll builds a pair of matrix profiles, one characterizing the camera's performance under lightbox-simulated Illuminant A, the other under lightbox-simulated D65. …These profiles are functionally equivalent to ICC profiles. …The profiles built into ACR are simple matrices with white point, primaries, and TRC. … The specific colorimetric interpretation of a given image is calculated from the base profiles and the selected white balance settings.

All that the Calibrate tab controls do (and indeed, all that they possibly could do), is to adjust the primaries of the built-in profiles. … There is absolutely no mystery about the function of the hue and saturation sliders in the Calibrate tab. They move the chromaticity coordinates of the respective R, G, and B primaries in x,y.

The Temperature and Tint controls in ACR interpolate between two matrix profiles that supply colorimetric definitions of the tristimulus RGBs produced by the camera under a light source that produces tristimulus values that match a correlated color temperature of Illuminant A, and of the tristimulus RGBs produced by the camera under a light source that produces tristimulus values that match a correlated color temperature of D65. <<


At the end of the day, to push saturation via the sat. sliders in the Calibrate tab corresponds to the assignment of a "wrong", larger profile to the native image data.

Peter

--

[Denis de Gannes]

Quote " Quote (Bruce Fraser, 2005, Adobe Camera Raw Forum) >> For each supported camera, Thomas Knoll builds a pair of matrix profiles, one characterizing the camera's performance under lightbox-simulated Illuminant A, the other under lightbox-simulated D65. …These profiles are functionally equivalent to ICC profiles. …The profiles built into ACR are simple matrices with white point, primaries, and TRC. … The specific colorimetric interpretation of a given image is calculated from the base profiles and the selected white balance settings."

Surely we have moved way beyond this technology, 10 years in the advancement of sensor capability in digital cameras and the processing of raw data. Or are we locked into the past.

[Peter_DL]

see AlterEgo's response above.
The matrix part still lays the ground.
6 of 9 degrees of freedom with a 3x3 matrix are represented by the hue/sat.-sliders of the Calibrate tab.
Today's dcp profiles may just include further components, Lut(s) on the top of it. Irrelevant here.

-

[digitaldog]

Surely we have moved way beyond this technology, 10 years in the advancement of sensor capability in digital cameras and the processing of raw data. Or are we locked into the past.

Locked in what way? Old technology in what way?