Optoma HD8600 Projector Review - Update
Below we consider the Optoma HD8600's improved dynamic iris firmware.
9/9/10 - Art Feierman
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HD8600 Dynamic Iris Overview
When originally reviewed, I found the dynamic iris to be sufficiently annoying on occasion. When engaged, I believe it may distract a significant number of people, and annoying some people enough to force us to turn it off. Of course, turned off means no issues at all, but it also means black level performance suffers greatly. Part of what you are paying for in a projector of this class is some pretty impressive black level performance.
I'm glad to see Optoma has done some reworking, with one of the two settings. The HD8600 offers a choice of Dynamic Iris being Off, Cinema 1, or Cinema 2. I'll cover both modes in the discussions below. Cinema 2, it should be noted, is essentially or completely unchanged. Cinema 1, now, however is very smooth. The leaves (or pedals if you are a flower fan) of the iris is now barely visible on darkest scenes. They are still very visible in Cinema 2 mode.
Let's Talk Dynamic Iris From A Practical Standpoint
First of all, you don't need to use a dynamic iris all the time. It's a waste, and might even be a distraction if you are watching a sporting event, which is rarely dark (night fishing?). If the iris engages at all, it's not going to do anything you would notice as a benefit, and you might just notice it once in a while.
The same would be true of a lot of TV viewing. Sitcoms are usually nice and bright, and hey, you'll probably have a little light on in the room already compromising the black level performance that the iris is supposed to help, so why notice iris action at all?
So, mostly it's movies, and high quality HD content, if that content is pretty dark, where you want it.
Sadly most movies aren't feasts for the eyes, and if you are watching the typical romantic comedy, you likely aren't focused on blacks and dark shadow detail.
But, then comes along the movies and other content where it matters. Night scenes in movies like The Dark Knight, look WORLDS better on a projector with great black levels than on some $999 DLP home projector. That folks, is why you want great blacks, those dark scenes "pop", instead of looking somewhat washed out.
I should note, that dynamic iris issues in general, aren't much of a problem on fast action flicks - say Transformers, or the Bourne series. Images and scenes change so fast that most visible artifacts are completely buried by the flurry of moving content and panning views.
It's when you want to kick back and take in that really excellent movie that you love your home theater for, where it matters. Hunt For Red October, The Fifth Element, Casino Royale, Casablanca, I've got over 200 Blu-ray movies here, and I really want excellent blacks on at least 75%.
So, where does that all leave us with the Optoma HD8600 in its current iteration of the dynamic iris.
HD8600 Iris Functionality
First things first. The Optoma manual iris and dynamic iris are separate. They do not "work" together in any way, which I had to confirm. I wanted to make sure, for example, that reducing the manual iris from 9 to, say, 4, would not reduce the range of the dynamic iris. Close down the manual iris, and the image dims - bright objects and scenes dim, and so do dark ones and everything in the middle.
Based on some rough numbers, think of it this way. A dynamic iris setup could lower black levels by perhaps 80% or more on really dark scenes. The manual iris, however, droppping from 9 to around 4 or 5 only increases contrast by about 10%. In other words, if you don't need more lumens, lower the manual iris, but only expect very modest improvement in blacks due to contrast changes. The change in contrast probably isn't noticeable, but you will definitely notice the overall drop in brightness. A Dynamic Iris, will do far more for your blacks and near blacks, on a dark scene, than using a manual iris. Using both, though, can be a plus!
Remember - a dynamic iris cannot increase the dynamic range of any image. It can only raise and lower the overall levels, allowing for dark scenes to be mostly darker, but with near bright areas maintaining most of their brightness.
Cinema 1 dynamic iris setting has little effect on bright scenes, but does work modestly well on dark ones. Over all, the action is very, very smooth. I had to do some serious looking at first to even tell it was doing anything. Kudos! But bigger kudos would have been in order if the blacks were a bit deeper, and it was still smooth.
Cinema 1 reduces black levels far, far less than Cinema 2. My measuring was pretty imprecise, but figure the difference between the two was probably at least 250% lower black "brightness" on dark scenes, with Cinema 2.
Cinema 2, it should be noted, is essentially or completely unchanged. Cinema 1, now, however is very smooth. The iris is now barely visible on darkest scenes. They are still very visible in Cinema 2 mode.
Let's look at some images. I've got two sets for you:
First pair - you are looking at a quick mask I put up so you can see part of the letterbox across the top. The actual image was a submarine shot from Red October, one that's much darker than the second sequence. The first image is Cinema 2 mode, which is a whole lot darker than the second image. The area that's part of the letterbox is the lighter gray going from one end to the other. Below to the right is part of the top of the movie itself. (I converted these images to grayscale so that the slight color shifts wouldn't distract.) Bottom line, Cinema 1 just isn't knocking down the black levels anywhere near as well as Cinema 2.


OK, more fun - below are three photos of a pair of subs in Hunt for Red October. From top to bottom, the images are the same but for the dynamic iris changing from Off, to Cinema 1, to Cinema 2:



The exposure is the same for all three images above, only the dynamic iris setting changes. With the dynamic iris off, the image is brightest, which is to be expected in a consistently dark scene like this one. With Cinema 1, you can see the overall image is a little darker, and you can see a change in the darker area on the left (there's a bit of a soft point sticking out from the left), which I believe is the iris. Finally Cinema 2, which is darker still and now you can see some very obvious impressions of a mechanical iris, around the coning tower of the further sub. Rather nasty. But then you'll rarely encounter a scene quite like this one. In the case of this scene, when watching, you might think that iris shadow is part of the effects. It's obviously not, however, as these images show.
Basically that tells me that they really are pushing the limits with their Cinema 2 setting. Perhaps they should back it off just a little more.
Cinema 1 is extremely watchable, but it's not going to make the HD8600 competitive in relative blacks with say the JVC RS15, or even the Epson UB projectors, or Sony VW85, but it should put them similar to say, the Panasonic PT-AE4000, Sanyo PLV-Z4000 and BenQ W6000, which I count as basic "ultra-high contrast" projectors. That's not really a terrible place to be, in fact it means pretty good black level performance.
Want to put on Transformers?, Sure, kick in Cinema 2 iris mode, you'll rarely notice the iris, and you will notice that dark scenes "pop" more.
But, much as I love those dark blacks, I can't make it through Hunt For Red October in Cinema 2. Cinema 1 will have to do.
Above image from The Hunt For Red October (Blu-ray disc). The HD8600 looked especially fine on scenes like this one, in Cinema 2, because there are enough bright lights in the background to limit iris action. Not so in some different, darker scenes.
I should also note, that when the iris shuts down in Cinema 2, you can actually see that the iris is unevenly affecting the image - you can literally see the iris "pedals" for lack of a better term.
Here are two very dark shots - same image, Cinema 1 first, Cinema 2 below it. While this sub scene is very dark, notice the illumination of the brighter areas above the sub - the water. See the iris? See the iris mostly disappear on the Cinema 1 shot?
Since I also took both shots with the same exposure, it also gives you a good idea of the difference between the two iris setttings...
HD8600 Projector - Conclusions: The Impact of the Dynamic Iris "Fix", on the Projector's Value Proposition
It's a Better HD8600
I'm still not 100% pleased. I thank Optoma, though, for a dynamic iris setting that still lowers black levels significantly, and is very smooth. My reservation comes from the significant difference in black level performance between Cinema 1 and Cinema 2 iris settings.
Cinema 1 is sufficiently smooth that I have to believe they could have come up with still a 3rd iris setting, that falls between Cinema 1, and Cinema 2, still pretty smooth, but with better black level performance. OK, I'll settle for 3 distinct dynamic iris settings in Optoma's inevitable HD8600 replacement.
The big question remains - with the improved iris, how does the HD8600 stack up with the competition overall?
Obviously, definitely better. This improvement might allow for a different decision between choosing between the HD8600 and several other projectors for a number of buyers. For those concerned with the iris on the earlier version, I would think those considering the Sony VW projectors, plus DLP projectors in the general price range, may want to rethink the situation. The blacks might not be up to most of those others, in Cinema 1 iris mode, but on the other hand, you get a really sharp projector, and other benefits. This fix, though, likely wouldn't make a difference to someone considering the JVC RS25, but, perhaps one looking at the RS15.
The Optoma HD8600 projector is a much better one for the fix. It's now one I could own. I could not have owned the earlier version. I'm not saying I'm trading in my JVC, but, I lie awake dreaming of having the HD8600's almost 1200 lumens in brightest mode, compared to the JVC with only about 2/3 the brightness.
The Hot Product Award bestowed upon the HD8600 back end of last year, was originally close thing, with the iris being the threatening issue. With this update, let's say that Hot Product Award is now very solidly deserved.
I also reflected upon how the HD8600 might have fared differently in our Home Theater Projector Comparison Report (1080p). Let's just say, that at the time, the Optoma was not seriously considered for an additional award. This Optoma would have at least been considered. To try to second guess my results now, 6 months later... Better to focus on all the new home theater projectors coming out.
Final thought - the HD8600 is back in action today, as I finish this. It's college football time, and my JVC with a now dim lamp approaching its 2000 hour life, likely isn't putting more than 500 lumens on the screen in any mode. I started out with my JVC, but with some friends on their way over, a good picture with the JVC requires the room to be pretty dark, too dark for what I prefer for group sports viewing. Now the HD8600's fired up. The difference of going from one to the other isn't night vs. day, but it might be described as dusk (JVC) vs. day (Optoma). And I can also tell that the Optoma is slightly sharper.

