Originally Posted by darinp2
I was told at CEDIA that one mode didn't do dynamic gamma and one did. I explained to them that "no dynamic gamma" could mean no gamma changes at the chips (before the lens iris) or no gamma changes at the lens exit and screen (just near white crushing). They didn't know which it was.
Could it be that auto 1 doesn't apply any dynamic gamma, which leads to shadow detail crushing to our eyes since they generally require bigger relative differences with dark things to see the same amount of detail? If the iris just closed without changing the signal at all then I would expect some reduction in visible shadow detail to most people when the iris was near the minimum size.
One interesting test might be to put up a 10% video window on black and measure the center of the screen with no DI, auto 1, and auto 2.
There is also the 5%/0% 4x4 checkerboard on the 2nd edition of the Spears and Munsil disk. If the signal wasn't changed (just the iris closed) the intra-image CR for that image shouldn't change much between DI on and DI off, but if gamma was applied the intra-image CR for the image should go up with the DI enabled. I figured this is a good test pattern to show people an advantage that a DI can bring to intra-image CR and maybe address those who have said that they don't care about on/off CR because they only care about mixed images, not blackouts.
I think it would be really interesting to see the intra-image CRs for that test pattern for the JVCs and Sonys, although it can depend a lot on calibration. Not that you don't already have enough requests for information Jason.
Darin, hi I got you're PM earlier, I just need some time to read over it.
using this specific scene as an example, here's the best way I can describe what I was seeing:
with the iris off and manually clamping to it's lowest position, it looks a bit 'flat' but can still see the subtle details, similar in appearance to my RS55. On my HP, I'm wishing the black floor would appear lower.
in auto iris 1, the iris will clamp to a smaller aperture and it crushes the details. Here is why I think it's some kind of gamma processing. When I do the 'menu test' (bring up the menu to force the iris open), then shut the menu off, I can see the iris close quickly, details are still there but then a fraction of a second later, it seems some processing kicks in and squashes the details.
in auto iris 2, the iris clamps the same but the details are still there and I'm appreciating the lower black floor with this configuration.
without knowing exactly what JVC is doing in iris 1 or 2 position, that's the best way I can describe it. regardless of the specific technique, I think it's impressive to see such a dark background with those fine details popping through, it's convincing in a way I haven't seen on the previous JVC's and definitely not on the Sony 600. It's not perfect though, when that scene transitions to Tom Cruise in the chair, you can definitely 'see' the changes going back and forth but it's not as distracting at the iris on the 600 in the spiderman scene @ 29:00.
I hope you to get to analyze this soon, I'm certain you'll be able to deep dive into this much better than I can. I'll take a look at a 5% and 10% window later to see if this makes more sense between the 3 settings.