Optoma HD803 Projector: Lens Throw and Lens Shift
As mentioned on the first page, HD803 has no adjustable lens shift, which makes it pretty much either ceiling mounted or table top. The shelf option is basically non-existent. The projector will end up being placed (due to the significant fixed lens shift), either well below the bottom of the screen, or ceiling mounted well above the top of the screen. If you are using a 100" diagonal 16:9 screen, that offset is going to be just over 16 inches (above the top or below the bottom of the screen surface).
In terms of placement distances; for a 100" diagonal screen, the front of the lens can be as close as 13 feet 6 inches, to approximately 16 feet 2 inches from the screen. That's only a 20% range, far less than the range offered by LCD and LCOS home theater projectors.
A good place to start in determining if the HD803 is for you, is to see if you can place it in your room. If your ceiling isn't too low, however, you should be fine, when ceiling mounted, as that's where you have maximum flexibility. If ceiling mounting, try to get some space between the projector and the ceiling (not flush mounting) as the hottest part of your room is the six inches closest to the ceiling. Being down 8 to 12 inches means better ventilation, a cooler running projector, and ultimately probably a slightly longer lamp life.
Optoma HD803 Screen Door and Rainbow Effects
I love 1080p resolution projectors - pixel structure visibility is no longer a real issue.
I viewed the HD803 in my theater room at various sizes, partially filling anywhere from about 100" to about 120" diagonal of my 128" diagonal Stewart Firehawk G3 screen. To make out any pixel structure at all in credits or stationary type and graphics on the screen, I had to lean foward and strain, and then only at 120 inches diagonal, and I have really good vision. I never could spot pixel structure in any normal viewing. Sitting 12 feet back from a 120 inch diagonal screen, is fairly close!
No rainbow effect: The HD803 is a classic DLP projector, however it has a 6X speed color wheel, instead of the usual 5x. That means even fewer than the normally very small portion of viewers may see rainbows (which are most visible when fine edge white areas are moving across a dark background). That also means even those rainbow sensitive that see them occasionally on a dark movie scene, are not likely to ever see one while watching a football game, or a typical well lit sitcom. Fortunately for 95+% of the population (my best guess), rainbows will not be an issue. I happen to be slightly sensitive to the rainbow effect, mostly on fast moving bright objects on a dark background, and especially when I'm tired, or am moving my head. Truth is, it hadn't occured to me that I rarely noticed any rainbows during the 30 or so hours of viewing, until I noted the 6x spec. At that point, I said to myself, "you know, I was wondering why I had only spotted the rainbows a few times, despite lots of content viewing that would tend to make rainbows more visible."
I had owned two 5X color wheel DLP projectors prior to my JVC, and learned to live with the occasional rainbow (maybe a few times a movie), but, on principle, I always wished I they were less noticeable. I appreciated the Optoma after just coming from reviewing the InFocus IN82 with its 5X color wheel.
Bottom line, the 6x wheel may not be the perfect cure, but it may mean that the limited group of people that won't buy DLP projectors because they can spot the rainbow effect, is now an even smaller group.