In 2015, Microsoft released its first MR smart glasses hololens 1, and its upgraded product hololens 2 was released four years later. Compared with the previous generation products, hololens 2 adopts the display scheme of MEMS display screen + diffractive optical waveguide; the pixel resolution of monocular display is upgraded to 2K, and the angle of view angle is increased to 52 °; the experience in space perception, interactive positioning and other fields has also been greatly improved. This article is from s-dream lab. S-dream lab has professional testing equipment and technical team, and is committed to building an independent and authoritative ar evaluation institution. < / P > < p > the equipment to be tested is turned on in the indoor light environment, and the brightness gear is set as the sixth gear. The equipment to be tested is fixed on the detection platform, and the white field image is lighted for about 10 minutes. The test image is displayed by using s-dream Lab hololens 2 display app, and the main indoor light source is turned off In this evaluation, gamma scientific ned-lmd E100 is used for data acquisition. < / P > < p > hololens 2. The nominal field angle is about 52 ° in diagonal, in which the horizontal field angle is 43 ° and the vertical field angle is 29 ° as shown in Figure 3. < / P > < p > uses 50% of the center definition as the boundary condition, as shown in Figure 4: the abscissa is the angle range, the ordinate is the definition measurement value, and the red dotted line represents the boundary threshold. When it is lower than the threshold, it is determined that the position is not the field of view of hololens 2. < / P > < p > the measured vertical field angle of the left eye is about 28 ° and that of the right eye is about 28 ° which is very close to the design value; the measured horizontal field angle is about 33 ° in the horizontal direction. Considering that hololens 2 does not fully use the horizontal display ability in the scene rendering process, the results are only for reference. < / P > < p > the distribution of the central field of view of the left and right eyes is shown in Fig. 5. The definition of the left eye is close to that of the right eye, and the left eye is better than the right eye at high frequency; it can reach more than 0.6 under the condition of 4 pixel width. It should be noted that the definition of hololens 2 is too low to output effective measurement results for the width line of 1 pixel. Compared with hololens 1, the definition of hololens 2 is obviously decreased. < / P > < p > when the brightness is adjusted to the highest gear, the maximum brightness of left and right eye center field of hololens 2 eye box is 787nit and 777nit respectively, which can be used normally in indoor lighting environment. The performance of hololens 2 in luminance uniformity evaluation is poor, and there are obvious dark corner areas in the corners. In the eye point position, through the LMD rotation around the eye point, the brightness data of nine positions in hololens 2 field of view edge and center were collected. The statistical results showed that the brightness of the four corner position was far lower than the center brightness value. The color accuracy of hololens 2 in white field image is not high, and there is obvious color deviation. The color temperature of the central point of the left and right eyes were 5443k and 5295k respectively. < / P > < p > in the actual test, based on the s-dream lab display software, the measured horizontal field of view angle is about 33 ° and the vertical field angle is about 28 ° which is close to the theoretical value in the vertical direction; the brightness uniformity of hololens 2 is poor, and the brightness of field edge is far lower than that of the center of field; the clarity of the left and right eyes is above 0.6, slightly lower than hololens 1 under the condition of 4-line pair width. < / P > < p > hololens 2, as the latest product of Microsoft hololens series, adopts the optical display scheme of laser beam scanning, and combines with the waveguide plate to realize larger display field angle and higher display brightness, so that the application range and immersion feeling are significantly improved. But at the same time, there is also a problem of poor uniformity of color and brightness, and the clarity is reduced compared with the previous generation of products. gather and watch! Huawei P40 Pro evaluation: excellent mobile phone photography elegant design, do you like it?