Optoma's newest home theater projector is what many have spent years waiting for - an affordable, high-quality 1080p projector with a solid-state light source. For a retail price of $3,999, the Optoma HD91 combines the features and functionality of Optoma's top of the line home theater models with an all-LED light source anticipated to have a life span of 20,000 hours. The HD91 does not cut corners, and the projector includes all of the modern conveniences (like a long zoom lens, lens shift, frame interpolation, detail enhancement, and full HD 3D compatibility) that home theater enthusiasts have come to expect from this class of projector.
Editor's note: this article has been updated. Information relating to the cost of the projector has been corrected, and our evaluation has been edited to incorporate this information.
The Viewing Experience
We set up the Optoma HD91 on a rear shelf in a light-controlled room and connected it to our Oppo BDP-103 reference Blu-ray player over HDMI before turning the power on. The image jumps to life on the screen mere moments after you press the power button. One of the advantages of LED projectors is that they require no warm-up period, and instead start up at their full brightness.
The first thing we noticed, and one of the important limitations of the HD91, is the projector's relatively low image brightness compared to competing home theater projectors. Our test sample measured 517 lumens in Cinema mode at full power, which is low by today's standards. However, if care is taken in positioning and mounting the projector, that is still enough power for a 120" diagonal 1.3 gain screen, so the HD91 is still capable of large-scale projection.
The image without calibration can look odd, especially if one is accustomed to the appearance of lamp-based projectors. Color is intense, with very high saturation and brightness, while black level is only average. However, these flaws were easy enough to remove thanks to the projector's extensive calibration controls, and the resulting image is smooth, life-like, and accurate. Shadow detail is particularly impressive once the gamma curve has been fine-tuned.
The HD91 has a number of image enhancement features, most of which are located under "PureEngine" in the Advanced image menu. UltraDetail increases detail perception (we left this set to "HD," which is the middle setting) while PureMotion is a frame interpolation system (we left this either on Low or off, depending on the type of content being used). There's also an iris-like system called DynamicBlack, though rather than a physical iris, the system uses changes in LED power to adjust image brightness.
The end result of all of our tweaking was an image that had vibrant color and excellent depth. Foreground objects seem ready to leap off of the screen thanks to the projector's high contrast in most scenes. The projector's black level is incrementally higher than some other home theater projectors that have aggressive automatic irises, but this only becomes apparent in scenes where black is a major component of the image (such as dark scenes in movies or scrolling credits) and was not apparent in mid-toned or bright scenes.
When it comes to 3D, image quality was quite good. The HD91 uses either radio-frequency or DLP Link synchronization at a refresh rate of 144 Hz, which means little crosstalk or ghosting. However, given the light output limitations of the projector, we would not push screen size over 100" diagonal for 3D viewing.