On another note, I was in sports-watching mode with my RS20 today and found that my custom gamma curve didn't take kindly to red uniforms (such as the AZ Cardinals or my beloved NJ Devils
), which looked rather flat and lifeless. I know it was the gamma curve causing this because temporarily switching to any preset gamma curves at or above 2.2 with my customized settings was bringing them back to life. I quickly figured too much of my gamma curve was below 2.2, so after the games ended I went to work with rebuilding a new one. For this new one I also targeted a gamma of around 2.4 for the bulk of the curve, but instead of starting as low as 1.8 - 1.9, I instead went for the beginning of the curve starting at close to 2.2 and very quickly rising to the 2.4 level (fully doing so by 15% stimulus), at which point it's essentially flat the rest of the way. This new curve still accomplishes the original goal of the punchier image of a higher gamma but gives you the good shadow detail of a lower gamma, essentially the best of both worlds.
For any kind of custom gamma curve building, here's what I've found is the basic procedure you should do. First, have your grayscale already tracking close to D65. At this point, I believe most of us should already have this accomplished.
Then, load up the JVC preset that most closely matches what you want to target, keeping in mind that the JVC presets all track between .05 - .1 lower than what they claim. They also have a slight dip at the very top end that you should not bother trying to correct, as this is at exercise in frustration (at best) where you will endlessly be chasing around some other point of nonlinear gamma tracking if you do.
Anyway, to create a lower gamma starting point, just take the 5% input point and raise it on up so its output value is close to the 5% output value of where you want the gamma curve to start. For instance, JVC's 2.2 gamma curve has the 5% output at 48, so to have your gamma curve begin at 2.2, you'll want to set your 5% output at around 50 (remember, JVC's gammas track a bit low). That should be all, but before you go into further grayscale tweaking with the individual RGB gammas, do a full grayscale reading to both make sure that your grayscale settings are still optimized as much as possible with your current gain and offset color temperature settings and that the gamma is really tracking as you want it to.
One other tip I'll share for final gamma tweaking is that you really should use 2 custom gamma curves during tweaking thanks to JVC's finicky gamma controls. The reason for this is because you don't want to make a change to a fine-tuned gamma curve only to find that JVC's interpolation / smoothing with your change actually made things worse than they previously were.
For this reason, anytime you make a change that improves the tracking, copy it to the the other custom gamma you're working with, and continue working on that one. Anytime you make a change that degrades tracking, all you need to to do revert back to your prior settings is switch back to the other custom gamma mode, rather than go through the painful effort of trying to undo the changes to the gamma curves that you made.