Originally Posted by Dominic Chan
I should point out that JVC's Autocal works at a low level and calibrates the "base" gamma curves. It has a direct impact on "additional" calibration including manual calibration, autocal implemented in "third party" calibration software, even 3D-LUT as none of those have the same granularity as the JVC autocal (256 points, or possibly even higher according to bobof's "sniffing"). All other calibrations ride "on top" of the base gamma and can thus inherit the defficiencies of the JVC Autocal.
The referenced LightSpace "anti-autocal" article probably pre-dates the inclusion of autocal in LightSpace
. Either that, or it’s meant to cover the a** when people complain about LS autocal.
You have confused what AutoCAL mean. Are you LightSpace or CalMAN user?
AutoCAL is a CalMAN name for a feature, which is using real-time adjustments of multiple times of the same point, guessing what RGB adjustments to do and then move to next point. So to perform 26-Point Grayscale (with LG for example...which as 1024-step 1D LUT), it can take 100-300 readings...reading multiple times these exact 26 points.(according to the dE method you will choose and how tight you want your dE, it will take less or more). If you need different gamma target you have to re-run the whole AutoCAL again.
LightSpace, for exact same application, you can take 33-Point Grayscale and then from these 33 grayscale measurements, it generates at-once-one 1D LUT 1024-step table. If you need other gamma target, then using the same measurement data (you are not take new measurements), you ask to generate a different gamma LUT (2-3seconds it takes), this is called 'display profiling'.
If you like, you can use more points, like 46-Point Grayscale we have found that it provides better results.
When you are using JVC or Sony calibration (you say as AutoCAL) its doing exact the same, from one sweep of grayscale (you can create a custom grayscale patch set with up to 101-point Grayscale inside of any levels you like, and import it to LightSpace) you do exact same procedure, from measured data of one meter read per each different point.
So AutoCAL, don't mean the same between software, just the name is more popular from CalMAN users, of what this procedure is doing.
CalMAN has profiling capabilities also, but its not called 'AutoCAL', its LUT capabilities, so profiling; 'Lightning LUT' is named etc.