Originally Posted by JonStatt
So basically the fixed aperture (or dual aperture for the higher 2 models), remains the same. It is an ADDITIONAL aperture introduced into the chain, and it is specifically to help with dark scenes and is totally out of play for light scenes. This is my understanding so far. If so, that is exactly the right implementation in my opinion. Nevertheless we must remember that definitively if the aperture closes down it MUST affect bright objects that would be displayed at the same time. So for example stars may be less bright, or lights in a city nightscape. For this reason I suspect hardened videophiles will still elect to switch this off or keep it on a low setting. Native contrast is still the direction to improve in (which JVC continue to do).
Yeah I was just thinking about that last night as I watched some of the original star trek series (Blu-Ray) on my RS55. And then some clips from sci-fi movies like Prometheus.
I was experimenting looking at the effects of brightening and dimming the image via the iris. As usual, making the image brighter increases the perception of clarity, detail, color richness, image "punch" and realism, as well
as image contrast. The contrast may be measuring less when opening the iris, but perceptually my eyes detect the brighter areas as brighter more distinctly than I see the darker areas get lighter, so it looks like the overall contrast is improving. I love this effect to be sure, but of course an issue is if you keep getting brighter and brighter, the effect of raising the black levels becomes more evident once you are viewing lower APL images. So it's always a trade off.
I tend to like the image fairly bright for the punchiness of the image, but I'm so cognizent of bulb dimming that I tend to keep the iris well below open, because I want head room to increase the brightness as the bulb ages. (In other words, I don't want to start of getting used to as bright an image as possible, noticing it dimming over time, and having no recourse left to brighten it. If I get used to a somewhat dimmer image, then I can raise the brightness as the bulb ages OR as I increase image size).
But, anyway, I was left scratching my head wondering if compromise is inevitable, what would I prefer? A more consistently brighter image with all the goodies that go with it and live with less quality for lowest APL scenes, or dimmer with better low APL scenes. I was sort of leaning toward greater brightness last night, which actually got me thinking of the new Sony 4K and it's higher brightness. There was an interesting review of the earlier
Sony VPLW1000 against the JVC E-shift projector with both projectors projecting on the same screen (covering and uncovering each lens). The author reported the Sony seemed to blow away the JVC in punch, contrast and detail. But when the light output between the two was equalized, that difference disappeared. Which speaks to the potency of brightness alone.
But, the nightscapes you mention Jon can look "more believable," that is nigher in contrast with the city lights cutting through the darkness, when I brighten the image. It's the lowest APL images that tend to suffer from raising the brightness the most.
So, thinking about this I remembered how, without native contrast being increased, you can't have it all...or even get close...with a dynamic iris. I presume that the iris (set aggressively) will allow for those bright punchy
scenes at daytime, but in clamping down for night scenes I'd lose some of the contrast excitement I'd get if I'd left the IRIS set in the same open position. Though, as I understand it, the gamma is often tweaked while a DI clamps down, to try to up the apparent contrast in darker scenes (mostly lower APL?)
I really have to see the DI in action to see if it's something I can live with or that it adds to the overall experience of image quality.
It all makes me very curious to see the new Sony 4K, to see if it's overall brightness, and the punch it would bring the image, would ultimately win me over the JVC.