Analysis explains why sapphire Apple Watch and Edition lag behind glass Sport display outdoors

Apple Watch Sport’s Ion-X Glass display (left) vs Apple Watch w/ Sapphire display (right)

DisplayMate is out with a new report today, this time applying its usual detailed analysis to the different displays that come with the various models of Apple Watch. In case you didn’t know already, Apple is using a sapphire display on its pricier, mid-range collection of Apple Watch, as well as with the higher-end Apple Watch Edition. That’s opposed to the Ion-X glass display on the less expensive, entry-level Apple Watch Sport models. But the report shows a detailed analysis of what many users have already noticed: despite sapphire being more scratch resistant, in many cases the cheaper glass display performs better in terms of screen reflectance and visibility in outdoor lighting:

In the dark both Apple Watch displays appear and perform identically, but in ambient light they appear and perform differently due to the difference in the Reflectance of Sapphire and Glass… For the Apple Watch Sport with Ion-X Glass we measured the Screen Reflectance to be 4.7 percent, while for the Apple Watch with Sapphire we measured 8.2 percent Screen Reflectance, which is 74 percent higher than with Glass… The 74 percent higher Reflectance of the Apple Watch with Sapphire means that its screen will reflect almost twice as much surrounding ambient light as the Apple Watch Sport with Glass. And it takes surprisingly little ambient light for that to make a significant visible difference…

DisplayMate goes over all of the specifics, including differences between the two displays for reflectance, ambient light performance, contrast decrease in ambient light, color gamut, and view angles, but the image they shared above speaks for itself: the sapphire display on the pricer Apple Watch models doesn’t perform nearly as well in terms of visibility in ambient light. The report notes that the test simulates “moderate outdoor lighting in the shade or an overcast sky.” 

The background is much brighter on the right Sapphire display due to its 74% higher Reflectance compared to the Glass display on the left. The reflected ambient light reduces the image contrast of the white text and graphics, and also the color saturation and vibrancy of the red second hand. The large differences between displays are very obvious and striking.

The report notes that Apple could improve its sapphire displays in the near future to improve reflectance and visibility thanks to new, incoming technologies: “by using some new advanced technologies, the Reflectance of not only Sapphire but also Glass will be reduced significantly in the very near future for some displays, with major implications and improvements for both the visual and optical display performance.”

You can get the full, detailed breakdown of the two displays at DisplayMate.