Originally Posted by rrollens
Can someone please explain to me the advantage(s) of adding a lut box to the Sony A1E?
Thanks in advance for the response(s).
Hi, the TV's are coming with some calibration controls which give the capability to calibrate it's Grayscale/Gamma/Color Gamut. To this area Sony has 10-Point RGB Balance controls to be able to calibrate Grayscale/Gamma (while LG's have 20-Point for example) but no adjustments for Color Gamut adjustments (Sony has only global control or color and tint while LG has Full CMS (adjust Hue/Saturation/Luminance per each primary/secondary color, but may not work as expected); so when you have full CMS adjustments you can calibrate 6 colors.
The problem is that when you are moving away from the calibrated points and measuring other luminance or saturation levels, the errors are will be increased, so the more points (of different luminance/saturation levels) you measure the more errors you will locate. Classic charts or limited points been used usually don't show these issues.
Generally fixing only grayscale issues doesn't guarantee an accurate picture, you get only some good looking Grayscale charts with low dE, the real performance can still have a lot of errors because you are correcting only a few points, away from skin tones or memory colors correction, most of the movies are using mid-low saturation/luminance range colors if you analyze movies data's; most of the colors have mid-low levels, away from the edge of the gamut (100% Saturation / 100% Luminance); the colors which commonly calibrated using display internal calibration controls (Sony don't have these CMS controls) and default calibration software workflows.
Sony especially after a perfect calibration using internal controls only is suffering at mid-low end colors and this is something that is noticed with real content viewing.
Using 3D LUT you calibrate many different levels or saturation/hue/luminance, so your performance will be reference at any color, in 8-bit systems, the allocation of 17 nodes per component (17-Point Cube) proves that is best trade off between display/meter/processor hardware / measuring time / display stability and overall quality, that's why that size is commonly used at pro industry.
The most important is the total volumetric accuracy for the best final results, consumer displays has not so linear tracking to all it's areas, so a large cube with a profiling sequence that 17 or 21-Point Cube (4.913 or 9.261 Color Points) grid-based with equal spaced RGB values will cover all potential colors equally and give the most accurate correction.
With manual calibration using internal controls you have to take multiple adjustments of the available calibration controls, but usually one change at one area is affecting nearby area so at the end you will spend some hours only to do a 10-Point Grayscale calibration, until to get some good looking charts.
This is a RGB 3D Cube presentation; (ignore the 6 dots of colors.....which you don't calibrate since Sony don't have CMS controls); you see what points represent the Grayscale calibration you perform with Sony internal controls.
The average Caucasian skin tone resides well away from any grey scale, or primary color, this is why the ColorChecker patches is a good choice of measurement run (after Saturation runs) because they contains skin tones, grass, sky, etc.; which are memory colors.
With 3D LUT you will have to do only basic setup from your internal calibration controls, contrast/brightness/sharpness, select the native gamut option and pre-calibrate only 100% White....and then let the other thousand color points to be measured by (LightSpace/CalMAN/DisplayCAL/ArgyllCMS) and from the thousand points it will be measured automatically, the 3D LUT correction will be generated for 65-Point Cube (274.625 Color Points) for eeColor and the correction is stored to eeColor memony. From one measurement run you can create different corrections with different gamma value, to have a Gamma 2.2 3D LUT correction for older BD-Movies, 2.35 for not so old ones and 2.4 for the latest, or whatever other gamma you like since you have 6 memory slots.
Then you upload the 3D LUT correction file to eeColor 3D LUT Box. After that you take post-verification measurements.
I have posted some results from 3D LUT in a LG OLED here
, and Pioneer KURO there
; using LightSpace with eeColor 3D LUT Box.
Here is the 3D Cube presentation of RGB space using 3D LUT correction with 17 & 21 point cube size.
Ever Dolby Monitor which designed to be reference needs 3D LUT profiling to meet the tight tolerance in color errors that required for critical color reproduction for movie grading in post-production facilities.
For example Dolby Monitor PRM-4200/4220 has 2x 65-Point 3D LUT Tables slots, same size like eeColor 3D LUT Box features (which has 6 memories).
3D LUT is the best solution for reference quality SDR pictures, because REC.709 (blu-ray) is a colorspace which Sony is covering 100% calibrated and cover obviously blu-ray's mastered luminance levels also (100-120nits) so for SDR is the ultimate solution to transform any display to have reference level.
So if your calibrator can provide you 3D LUT calibration, since he will have reference meters (refernece spectro and fast colorimeter which has perfect low light capabilities because in 3D LUT the measured dark patches are a lot) then you gain even more fidelity and will have the best possible reference image for HT environment.