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Hi there.
I think I I have a basic understanding about calibration and profiling, however no matter how much I read the documentation, I´m still confused about some technical settings:
My setup:
Panasonic 4k TV
Set to the Widest Gamut (Native), about the size of the AdobeRGB.
Target Gamut – Rec 709.My Settings:
Calibration
6500k
120cd/m
Rec.1886 2.4Profile type
XYZ+matrix
CIECAM02 gamut mapping UNCHECKED3D LUT after profiling
Source colorspace: Rec709 ITU-R BT.709
Rec 1886 2.4
Gamut mapping mode Inverse device-to-PCS
Absolute colorimetric white point-scaling
IRIDIAS.cube
Full-RangeQuestions:
1. After the calibration & profiling, the following ICC file is created:
TV #1 2017-09-13 10-57 0.3128x 0.3292y 0.0001cdm² Rec. 1886 VF-S XYZLUT+MTX.icc
and of course, a 3D LUT.
The icc file when loaded into the VCGT (via DisplayCal), it seems to only affect the Black & White levels, Gamma and Grey Scale/White Balance and not the Gamut (as expected?). However the same file loaded in After Effects or Photoshop, seems to also affect the gamut. In fact, it looks like that my original TV Wide Gamut was just mapped into the REC709. When compared to the 3D LUT created (loaded in Davinci Resolve), ICC looks the same as the 3D LUT.
Why is that? I never set a target for the gamut mapping for the ICC.2. In the 3D LUT tab menu, there are two options for the Gammut mapping:
Inverse device-to-PCS. Does this mean the native Wide gammut is going to be mapped into the REC709 gamut?
PCS-to-device = REC709 to Wide gamut of the device?I´ve just checked the Argy documentation about gammut mapping, but I´m still confused.
3. Input Output Encoding options
My TV is set to Full Range both in its menu and in the Nvidia Control Panel. When is the output to be set to 16-235, (limited) in what circumstances?4. After the calibration & profiling, two .icc files are created:
TV #1 2017-09-13 10-57 0.3128x 0.3292y 0.0001cdm² Rec. 1886 VF-S XYZLUT+MTX
TV #1 2017-09-13 10-57 0.3128x 0.3292y 0.0001cdm² Rec. 1886 VF-S XYZLUT+MTX.Rec709.B0.0,2.4Gawn65 (bigger file size).What´s with the second one? What is for?
Thank you and I apologize if some questions have been asked before.
Hi,
The icc file when loaded into the VCGT
No, only the contents of the ‘vcgt’ tag (aka 1D calibration) is loaded into the graphics card videoLUT. See Calibration vs. Characterization.
When compared to the 3D LUT created (loaded in Davinci Resolve), ICC looks the same as the 3D LUT.
Why is that? I never set a target for the gamut mapping for the ICC.The only difference between a 3D LUT and ICC based color management is that the former is a “baked” transform, while the latter links the respective source and destination spaces on-the-fly.
Inverse device-to-PCS. Does this mean the native Wide gammut is going to be mapped into the REC709 gamut?
Table-based profiles come with two tables, device-to-PCS (in the case of display profiles, usually RGB to XYZ), and PCS -to-device (XYZ to RGB). In normal operation, only the PCS-to-device table of a display profile is used (because it is not used as source, but destination profile).
During 3D LUT creation, you can either use an existing PCS to device table (if available), or invert the device to PCS table. Inverse device-to-PCS is (usually) the more accurate but also slower (during creation) option.
My TV is set to Full Range both in its menu and in the Nvidia Control Panel. When is the output to be set to 16-235, (limited) in what circumstances?
This very much depends on the respective setup. If (e.g.) a NLE outputs video levels, then this usually hasn’t to be done by the 3D LUT if it is applied in the NLE itself (i.e. despite the output being effectively in video levels, the 3D LUT needs to use full range). If the 3D LUT is applied externally, e.g. via a 3D LUT box, then it receives TV levels, so the 3D LUT needs to be created with video levels encoding.
What´s with the second one? What is for?
The second bigger file is the 3D LUT in ICC device link format.
