- 1 Equipment and practice
- 2 Light & color
- 3 Sharpness and video processing
- 4 Conclusion
- 5 The Optoma UHD51 Is an Insanely Good 4K Ultra HD Projector
- 6 Optoma UHD50 and UHD51A Review – The Best 4K Projector of 2018?
Thanks to Texas Insights’ “XPR2” technology, which quadruples the resolution with an optical actuator, UHD-compatible projectors are becoming increasingly affordable. But the devil is usually in the detail and the buyer had to be always willing to compromise: Either the 24Hz cinema frequency was not reproduced correctly, the HDMI bandwidths did not meet the current HDMI 2.0 standard or lacked a 4K interframe calculation.
The new Optoma remote control is small and elegant. It is limited to the essentials and allows reliable control.
The new UHD51, which will soon also come on the market as UHD51A with integrated Alexa voice control, is said to be a thing of the past and other teething troubles. Above all, the 4K-compatible “PureMotion” intermediate image calculation represents a unique feature of the Optoma – it offers no other projector in this price range. The same is true for 3D, which more and more projector manufacturers delete. With these two features, Optomas Neuer could become an insider tip.
Equipment and practice
Externally, there are no experiments on the UHD51. Its dimensions are pleasantly compact, so that it can be well integrated even in smaller living spaces. However, this is less true for the black color, which was at least refined by a kind of striped piano lacquer. Before buying, the interested party should measure his space exactly, because the Aufstellflexibilität is DLP typical limited. Although an optical lens shift is on board, but allows only a fine adjustment to the screen. After all, the zoom range of the lens allows the usual image widths of 2 to 3 meters from this country customary distances. All settings are made manually on the device, it is recommended a permanent ceiling installation using a height-adjustable holder, which compensates for the installation deficits of the projector.
It is considerably more convenient with regard to the connections: In addition to the obligatory HDMI inputs, there is an analogue VGA input as well as various control interfaces for integration into an automated infrastructure. Especially up-to-date is the USB interface with up to 7.5 watts of power, this can be powered by the increasingly popular multimedia sticks from Amazon (Fire TV) and Google (Chromecast), so that another power cable under the ceiling unnecessary. Both HDMI interfaces offer the full 2.0 bandwidth of 18 Gbps, allowing them to handle 12bit HDR signals even at high frame rates (50 / 60Hz). Overall, the connection side of the UHD51 is so versatile and complete, as it rarely happens even in higher price ranges.
Both HDMI inputs comply with the HDMI2.0 / HDCP2.2 standard. Among other things, the USB sockets can supply power to smart sticks.
In turn, we have to call the optical interior design more conservative: The image is created by the classic combination of UHP lamp, color wheel and Full HD DMD chip. Innovations like a laser light source are not yet expected in this price range. On closer inspection, however, one recognizes that the image quality was in the foreground: Instead of a “Brilliant Color” -radiol with white segment, which especially the marketing values of a projector, the UHD51 uses an RGBRGB color wheel, which optimizes the color representation and reduces the DLP rainbow effect. In fact, the UHD51 hardly shows color flicker, so it can be used by more sensitive observers. In terms of volume, the UHD51 is quiet, but not inaudible. Especially the subtle hum of the XPR actuator (vibrating glass) can interfere with too close a sitting position. Therefore, a ceiling mounting is recommended.
Gone are the days of small fonts and confusing menus: both the structure and the layout of the UHD51 have been completely redesigned. All functions are quickly accessible in the modern Smart TV look. The remote control is also exemplary modern: Small, elegant, but still functionally reliable, it allows a speedy control.
Light & color
As with all projectors read the manufacturer’s information on the UHD51 inflationary: That the specified 2400 lumens at 500,000: 1 contrast are utopian even for the most expensive high-end projectors, recognizes the big-picture connoisseur quickly. The reality looks as always a bit more moderate: If you activate the “dynamics” preset, the UHD51 projects its uncorrected lamp spectrum onto the screen, which actually breaks the 2,000 lumen mark. However, the color representation here appears extremely greenish. Calibrated to natural colors remain around 1,200 lumens, which is a good value for a home theater projector.
The biggest weaknesses show current DLP projectors in native contrast, the UHD51 is unfortunately no exception: He provides around 1,100: 1 with good color representation, which becomes clear in a black that obscures dark scenes with a gray haze. Luckily, in the picture menu, the “Dynamic Black” function, which adapts the luminous flux of the lamp to the picture content and thus increases the dynamic range to more than 2,000: 1. Together with the DLP-typical high ANSI contrast of 410: 1 results in an appealing image dynamics.
When it comes to color reproduction, the RGB-RGB color wheel pays off: without time-consuming calibration, choosing the right preset (see adjustment recommendations) will result in excellent matching of both the color space to the BT709 HD standard and the color temperature to the required 6500K / D65. Also, the light distribution (gamma) ensures a correct exposure of the image, in which no details in black or white disappear.
Color wheel without white
The Optoma UHD51 uses a classic RGBRGB color wheel, which offers several advantages in terms of home theater: The basic color frequency is doubled and the rainbow effect is thus minimized. Disturbing flicker is thereby the exception, the eye friendliness is increased. In addition, all colors are mixed exclusively from red, green and blue, as the video standard provides. “Last but not least”, the tints of the individual color filters are calibrated exactly to the target colors of the BT709 standard, so that the projector produces accurate colors purely visually and without time-consuming digital correction.
The color wheel contains each basic color twice, thus ensuring a video-conformant color production with little rainbow effect.
All this results in a much more natural image look than the brilliant color Brilliant Color wheels with yellow and white segments, all trimmed to brightness.
Many other projectors block a color wheel with white and yellow segments including disturbing side effects.
For high-dynamic-range content such as the UHD Blu-ray (like all previous projectors HDR10, but not HDR10 + or Dolby Vision supported), the UHD51 finally reaches its physical limits: Due to its limited black value, the factory setting brightens dark details so that they are clearly visible, but lose in subtlety and credibility. With a little fine tuning you can increase the HDR image depth, however, a gray haze remains in dark scenes. The UHD51 also does not have the original cinema color space (DCI P3), but effectively converts it to its HD color space. Correctly adjusted, the UHD / HDR image pleases, but it can not be compared with high-end models – but it also costs many times over.
3D only in full HD
Optoma has answered the wishes of the 3D fans: As one of the first UHD DLP projectors, the UHD51 supports 3D projection. Although appropriate glasses are not included, each DLP-Link glasses is compatible and inexpensive to purchase. The 3D quality of the UHD51 is typically DLP-like, but can not be combined with the 4K resolution.
During 3D rendering, XPR turns off and the native HD resolution of the DLP chip remains – the image looks correspondingly coarser.
The reason: The mechanical XPR actuator is not fast enough to quadruple the resolution of the 3D frequency (120 or 144 Hz). In 3D, the actuator is therefore disabled and the UHD51 behaves like a Full HD projector. However, this is not a disadvantage, because the UHD standard supports anyway no 3D presentation, all 3D material corresponds to the maximum of Full HD resolution.
Sharpness and video processing
Even though the affordable UHD DLP projectors all use the same XPR technology from Texas Instruments, the differences between the individual brands on the screen are astonishing.
The XPR2 system (right picture) improves the detail display compared to the coarser Full HD resolution (left)
The reason lies in the individual signal conditioning, which must distribute the resolution of the incoming 4K signal sequentially, because the XPR technology generates the resolution in four separate steps. The better the signal electronics, the closer the result is to the UHD original. The UHD51 achieves this task well; the pixel shift visibly reduces the pixel structure of the Full HD shifter and increases the sharpness of detail. However, the result does not match the quality of a native UHD projection or the XPR1 technology of the big brother UHD65. Also, the pixel shift seems to be subject to a certain series dispersion, because some devices “blur” the pixels more effectively than others.
“PureMotion” is a unique feature in this price class.
Unique in the price range of the UHD51 is its “PureMotion” intermediate image calculation, which can also be activated with UHD signals in three stages. It increases the sharpness of movement significantly and ensures more credible motion sequences in feature films, without destroying the “film look”. Here and there, however, there is sync micro-stuttering, which suggests an imperfect 24-Hz timing.
Thanks to good equipment, UHD compatibility, sufficient interfaces and modern signal processing including 4K interframe calculation, the Optoma UHD51 offers a high-quality entry into the new world of resolution. In terms of installation flexibility and black level, however, is still up.