Seeing double (resolution) with the Apple Vision Pro

This is just to provide a small correction to people who say that the Apple Vision Pro has an 8K display. It doesn’t really. It has an approximate 6K total display.

The error comes because Apple very carefully says it has a 4K resolution per eye: “And with more pixels than a 4K TV for each eye, you can enjoy stunning content wherever you are — on a long flight or the couch at home”.

Apple also very carefully states it has a total display resolution of 23 million pixels. Everything else is inference.

This is because we are dealing with two different units of measure, with pixels being equivalent to something like an inch, while a “K” is something more like a square inch.

For example when we discuss a 2K TV, the “2K” represents the lengthwise dimension. What we actually mean by “2K” is a resolution with the dimensions 1920 pixels by 1080 pixels.

In turn a “4K” TV has dimensions of 3840p x 2160p. It is more than double the total pixel count since we double both the width and the height of the 2K resolution.

A 2K resolution has a 2 million pixel density. A 4K resolution has 4 times the pixel density of a 2K screen, not 2 times. Here’s a listing of the currently available screen resolutions and their entailed pixel density:

2K = 1920 x 1080 = 2,073,600 pixels
4K = 3840 x 2160 = 8,294,400 pixels
5K = 5120 x 2880 = 14,745,600 pixels
6K = 6144 x 3160 = 19,415,040 pixels
7K = 7168 x 4032 = 28,901,376 pixels
8K = 7680 x 4320 = 33,177,600 pixels

So if the Apple Vision Pro has a 3660p x 3200p per eye, or 11,712,000 pixels. That’s actually a little bit more than a 4K resolution.

People get to the 8K number by inferring that two 4K lenses add up to an 8K lens. But from the chart above you can see that an 8K resolution actually resolves to about 33 million pixels. The Apple Vision Pro only claims a 23.4 million pixel resolution (11,712,000 x 2 = 23,424,000).

Again referring to the chart above, 23 million pixels is closer to 6K than it is to 8K. So, while Apple marketing doesn’t talk about it in this way, if we wanted to, we would have to say that the Apple Vision Pro provides a 6K total display resolution, not an 8K total display resolution.

A similar confusion between linear measurement and area measurement led Alex Kipman to claim that the HoloLens 2 had twice the field of view of the HoloLens 1. The HoloLens two’s resolution encompassed twice the area of the Hololens 1, but unfortunately that’s not how FOV is typically measured. As with the jump from 4K to 8K, it would have had to contain four times the area in order for the claim to have been true. Karl Guttag thoroughly covered the controversy on his blog.