An update on the LG TVs:
(But the WARNING applies to the other TVs too!)
Using the remote to turn off the HDR EOTF is very dangerous, as it is possible to cause major damage to the TV...
However, if you do use this mode, setting 'HDR Enable to On' the EOTF essentially becomes a standard power law gamma function (e.g. 2.2).
This means you will not see a PQ type EOTF with clipping instead of a roll off - you just get a very bright TV with standard gamma response.
(This power law gamma works for HDR calibration, but is pointed out for clarification, as some people expect to see a PQ EOTF with clipping rather than tone mapping/roll-off in this mode, and that isn't the case.)
Without 'HDR Enable set to Off' the TV will max out at about 400 nits, basically acting as an SDR TV.
With 'HDR Enable set to On' the display will typically see 600 to 750 nits peak luminance.
But, be warned, while there is no issue at SDR levels, at HDR levels there are real potential issues with image burn-in.
So small test patches (L20 for example) are suggested, and should be maintained on-screen for very short periods of time!.
The issue is that at HDR levels burn-in happens very, very fast - you have been warned!
It is therefore not suggested users do anything beyond short profile sequences (Quick Profiles?) because any long profile will likely damage the TV.
Even too many Quick Profiles with small patches can be problematic - and cause irreversible burn-in.
(There is no way around this as it is not peak values that are the issue - any patch above a nominal SDR 100 nits can actually cause issues!)
When playing back real HDR footage there is little issue as the, image changes quickly, with little time spend on static high luma scenes, as happens with any form of calibration.
That does make HDR calibration a real problem, and in reality there is no way to accurately calibrate these TVs for professional HDR use.
For SDR they can be very accurate.
You have been warned!
Mob Boss at Light Illusion