Test Results and Connectivity
Brightness. I measured the GT750E in Bright mode with the lamp also set to Bright at 2805 lumens, or about 94% of its rating. Game mode came out to 1883 lumens, which is still easily bright enough for the 90"-diagonal image I tested with to stand up to moderate ambient light, even considering the dimming effect of 3D glasses. Switching to the Standard lamp mode drops the brightness by about 24%, to 2140 lumens with the Bright preset. For lower ambient light levels, other presets range as low as 1137 lumens with the lamp's Bright mode.
Adequate brightness uniformity. Short throw lenses often have a problem maintaining uniform brightness across the screen, so it isn't surprising that I measured only a 61% brightness uniformity with the GT750E. That's a large enough difference, that I could easily see a cool spot in the upper right corner on a solid white or color screen. However, it's a small enough difference to be hidden in any screen filled with detailed images. I didn't see it in any of the video or game screens I tested with.
The back panel on the GT750E offers a well chosen set of connectors for the focus on games, starting with two HDMI ports for computers or video sources and a VGA port for a computer or component video, with Optoma including a component video adapter with the projector, so you don't have to buy one separately.
Other ports include S-Video and composite video, a set of RCA Phono plugs for stereo audio input, a miniplug for stereo audio output, and an RS-232 connector for controlling the projector from a computer or control box.
One port that deserves special mention is the VESA 3D port. The GT750E supports both DLP-Link and RF 3D glasses with DLP-Link support built in, and RF support depending on a supplied 3D emitter that plugs into the VESA port.
Optoma recommends using RF glasses since they don't need a line-of-sight connection. That means there's no chance of momentarily breaking the line of sight and having to resync. In addition, Optoma's RF glasses are smaller, lighter, and, frankly, less dorky looking than its DLP-Link glasses. On the other hand, Optoma also says its DLP-Link glasses offer better contrast, and my subjective impression is that they give more of a sense of 3D depth. Given that the GT750E supports both options, you might want to try both before committing to buying one kind or the other.