I thought i might relay on observation i had last night.
I re watched, Avengers Ultron, Thor Ragnarok and Infinity War. It was a long night.
I have been running sdr-709, sdr-HDR(color profile) and sdr-2020 in manual iris mode (-5) for quite awhile.
I watched the opening of Infinity War several times in manual iris, auto 1 and auto 2 to observe differences.
In both auto 1 and auto 2, after the marvel logo animation, there is the black out and slow reveal coming around a planet to see the derelect ship. Auto 1 and auto 2, both make for a complete black out, maintaining very deep blacks as the scene evolves. Manual iris does not reach a complete black out, but it is very good. So in this opening section, DI offers a clear advantage, but frankly while most other projectors absolutely need a dynamic iris here, the 990 does extremely well without it.
In the later part of the opening with Ebony Maw walking among the perished Asgardians, as he walk thru the scene, there are again notable differences between DI on and off. With DI on, everything about some of the scenes are dimmed, including the fires in the room and some other object highlights. With DI off in manual mode, the scene is almost indistinguishable as far as the dark parts of the scene, but the fires and object highlights are brighter and more dynamic.
At various points, higher scene APLs remove all DI dimming, but it is in the areas between, where various amounts of DI dimming reveal the true pros and cons of DI.
It is with respect to this range of differences in DI on and off performances, that i really appreciate the native contrast performance of the 540/790 & 640/990 projectors.
Our projectors can achieve a level of lower end image reproduction without the need of DI, which others projectors fall short of even with use of DI.
The experience just reinforces for me, my desire for my next projector to increase the native contrast of our projectors, while increasing resolution and improving any other image attributes.
I have yet to see a DI make up for a short fall in native contrast, without including some of the by products of DI mentioned above.
While current NX models take some interesting steps forward, i look forward to future generations of jvc lamp and laser platforms which feature contrast performance less reliant on either dynamic iris or dynamic dimming.
Ps... i did not even go into artifacts associated with what DI does with image processing to brighten up areas of the image, in order to compensate for the overall dimming. Or as one member might sum it up, it sucks.