HD91 Sports and HDTV Viewing
Let's start with sports! HDTV sports looks really good. First of all, the Optoma is very sharp seeming. Further enhancement using Ultra Detail increases perceived sharpness, but also may result in more noticeable image noise. That's not going to be an issue on a football field image, but you might notice in a closeup shot of one of the players' faces. But sports is about "the game" and not how flawless the skin tones of a player or an announcer are, so I have to complaints.
Dial in Optoma's Ultra Detail control to levels you are comfortable with (Set to On should do it. I find the other setting; HD+, to be over the top, although maybe you won't on sports). Even with it off, you get a really nicely sharp HDTV image. (Note, when we capture these sports images, you are looking at only 1 of the 2 interlaced frames (1080i) as a result, there's only half of the vertical resolution. Thus, the images inherently look sharper when the game is playing, not paused. Look closely and you can see some of those jaggies caused by the pausing.
Overall color is vibrant. The football field images with the large NFL graphics on the grass look great. Uniforms pop.
Vibrant is very good, especially for sports and doubly so if your projector isn't especially bright, as is the case with the HD91. While many projectors in this price range can put out up to 2000 lumens or so with pretty good color, the Optoma only has at most, perhaps 700 lumens with good color, so it can't handle more than a little ambient light, unless you have a very high gain, or ambient light rejecting screen.
HD91 ambient light for HDTV - the front right shutters are almost fully closed, leaking very little light
For most of our photo shoots for HDTV - notably sports, the shutters to the right of my screen are usually about half open, allowing in a fair amount of ambient light. One of the rear windows' shutters are similarly opened, and the door to the theater is usually open about half way, letting in lots of light from the large skylight out there.
But for this shoot, to get that nice vibrant look, the shutters to the right of the screen are almost fully closed (still leaking light) and the rear ones as closed as they get, with the door only open inches, instead of more typical setup for HDTV sports shoots, which is with the side shutters about half open, same for rear shutters, and door open about half way.
Side door to theater only cracked a few inches. Shutters on rear window fully closed
Generally when I have friends over, I prefer more light in the room than that, but it's hardly fully dark. You just won't want to be trying to read a magazine with this little light coming in (other than from the screen).
Again, this Optoma HD91 is a home Theater projector. It doesn't belong in a family room or living room where you con't have excellent light control of the room.
I use a Stewart Studiotek 130 with it's 1.3 gain, with these lighting conditions for all of the sports and other HDTV images above. I did not have the usual 6 or 7 rear down facing lights on, which are usually on for HDTV shoots of football.