Optoma HD81 Home Theater Projector – Overview

I mentioned the HD81′s ability to have particularly rich colors in dark scenes. The image below from Phantom, is a good example of the combination of saturated colors and good contrast.

Of course you’ll find more images rich in colors, for you to check out, at the bottom of this page, and on the summary page.

HD81 home theater projector: Black Levels and Shadow Detail

Overall, black levels are very good. The Optoma HD81 has a dynamic Iris, as do all the competing LCD based 1080p projectors. The purpose of a dynamic iris, is to adjust from frame to frame, which allows blacks to get blacker in dark scenes. While this is not as good as having inherently excellent black levels, since on scenes with some bright areas, the iris cannot close down, or only slightly.

In the case of the HD81, however, I think the dynamic iris is a non-issue. That is, I recommend not using it at all – turn it off from the menus. Why? Simple – it’s noisy. There are times when you can hear the iris at work, in the form of a short (1 second or less) grinding type of sound. This sound is loud enough to be easily heard (much louder than the fan noise for example). I think most users will find this occasional noise to be be – well – annoying.

So, you can try it on, but I suspect you’ll end up turning off Auto Iris. The other options for the Iris are fully open, or choose one of 16 steps to close it down. Closing down the iris part, or all of the way, will overall darken the image. As confirmed with Optoma (and others), closing down the iris also does result in very minor increases in contrast levels, however, I don’t believe any increase is significant, or for that matter visible. As a result, you can just use the iris to fine tune the brightness of the HD81, and not worry about black levels/etc.

So, without using the dynamic iris, I found the black levels to be very good. On really dark scenes, those LCD projectors with their dynamic irises (and lamps), can muster up a blacker black, but overall, the HD81 would have the advantage (and no issue of “seeing” a dynamic iris in action. (You can occasionally spot the action of dynamic features in scene changes, or even if the scene you are watching changes dramatically in brightness – sometimes it’s like someone is screwing around with the room lighting – sliding the dimmer up and down a bit.

In a side by side with the BenQ W10000 projector (HD81′s iris off), the W10000 (left) had a slight advantage in overall black levels (it too has a manual iris). The key point here, is that the difference is slight – not enough, in my opinion, to affect your decision between these two projectors, just one factor, and in this case a small one. In the image below, I have zoomed in on a frame from AeonFlux (not that you can tell). The BenQ is on the left, the HD81 on the right. What you are looking at, though is the black level in the letter box area. You can see that the BenQ is slightly darker. (I had used the irises of the two projectors to get the images as close to identical in brightness as possible).

And that takes us to shadow detail. Before I put up the usual images, I want to say that the HD81 has extensive gamma control of the image (10 steps). By altering the gamma, you can reveal more shadow detail, but there is a balance to maintain. Movies count on higher gammas to enhance contrast, than, say regular TV. For that reason, consider that the Optoma HD81 also has settings like Film, TV, Graphic, PC and User, four are preset gammas to match the content, and the fifth – User – allows you manual control of the gamma settings.

Our first comparison images are from Lord of the Rings. Immediately below it, is the same frame, but overexposed so that you can see the details in the shadow areas (right side, bottom, etc.), that are lost by the digital camera during the normal exposures. For your consideration, I have also included the same frame from the HD81′s closest competition, the W10000. You can click to enlarge images for comparison.

HD81 LOTR watchfireLarge
HD81 LOTR watchfireOverLarge
BenQ W10000 LOTR watchfireOverLarge

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