Apple Watch screen resolution estimate

Like the size of the Apple Watch we also haven’t learned anything about the screen resolution. Why? Maybe the final screen resolution hasn’t been decided yet (which seems unlikely). Or Apple just didn’t want to announce lots of nerdy specs to take away from the fashion appeal of the device.

Anyway: We know nothing. So is there a way we can determine what the screen resolution will be?

We can’t trust images from Apple’s website in this case, since they use higher-res assets in the screenshots to make everything look better in close-ups.

But there are also photos showing the actual device taken by people who had the privilege the visit Apple’s hands-on area after the keynote. I was able to find a photo on Flickr showing a close-up of the device in which you can make up pixels.


Find the original by Taro Matsumura on Flickr

A few things to note:

  • On the high-res image you can easily see darker lines running between the brighter lines/ This seems to be space between the pixels (see the image below).
  • You probaly don’t see horizontal darker lines because the device is leaning back a bit.
  • This gives us the ability to “see” the pixels.
  • You can also see fuzzy diagonal lines running across the image. These are the result of the moire effect. The lines between the pixels on the screen don’t exactly line up with pixels on the image sensor in the camera.

I picked on spot on the photo, zoomed in and calculated how many pixels where placed along a certain line, making sure I started on and ended before a dark line and also making sure I hit at least 2 “moire bands”.

Using the “known” width of the device and screen we can now determine how many pixels are in the entire width of the display.

There is one thing that I can’t really wrap my head around and that is the moire effect, because that makes counting more difficult. There occurs a shift in dark and light lines (which you can see in the example, just trace a dark line through a moire band), so there’s a reasonable margin of error here. If any one knows to actual correct way to count this, please let me know.

In the about 632 pixels in the image I attribute to the screen, every 2 to 2.12 pixels seem to amount to an actual pixel in the screen.

Results

By my calculations the Apple Watch has either a 300 or 320 pixels wide screen. Thats makes the screen have a vertical resolution of either 375 or 400 pixels. I don’t think the resolution will be different for the 38 or 42 mm model. The ppi will likely be higher on the 38 mm model. The entire UI will be a bit smaller that way.

At 300 x 375

The 42 mm model: ~312 ppi
The 38 mm model: ~360 ppi

At 320 x 400

The 42 mm model: ~332 ppi
The 38 mm model: ~385 ppi

Please let me know what you think in the comments.

7 Responses to Apple Watch screen resolution estimate

  1. Very nice, thank you! John Gruber, who was to-the-pixel accurate about new iPhone 6 and 6+ screen sizes (http://daringfireball.net/2014/09/prelude), mentioned that 320×320 square sounded “about right”. So I’m leaning towards 320×400.

  2. Jay Riley says:

    Looking at that link, John predicted a “3x” retina display resolution of 2208 × 1242 for the 5.5 iPhone 6+, but the device as announced has 1920×1080. Still his reasoning was sound.

    What is apparent from the screen shots in the introduction and stills on Apple’s site is that the display area of the screen has a 1.25 to 1 height to width ratio, whatever that resolution may be. Since the photo album display is an arrangement of 9 x 9 photos, it would make a certain amount of sense that if not a power of two it would be a number evenly divisible by 9.

    A display 360 pixels wide by 450 tall would be in the ball park of the numbers you mention, have the screen ratio shown on Apple’s site, and conveniently be evenly divisible by 9 in both dimensions.

  3. The demo’s show that with the Digital Crown you can zoom in on the photos. This way you can show any amount of thumbnails on the screen. It’s not clear to me if the zooming “snaps” at certain points, but if so, than you have a valid point. Hadn’t considered that.

    But based on the calculations I made using the method described in the post 360 x 450 are a bit to many pixels. There is a margin of error of course.

    Someone told me that the Facebook Origami team also guessed the display would be 320 x 400. I haven’t found a source for that claim, but I think that resolution is more realistic power consumption and display quality wise.

  4. Josh Worth says:

    Very cool. Zooming in on a photo and actually counting the pixels seems like a pretty sure fire way to figure this out. Like you said. it’s probably possible to look at the moire pattern and the resolution of the photo itself to get some more info, but that’s over my head.

  5. Pingback: The New Apple Watch (x times 2)

  6. Pingback: Apple Watch vs. Android Wear Smartwatches

  7. The Colleague says:

    From an inside source:

    42mm : 312 x 390 (retina)
    38mm : 272 x 340 (retina)

Leave a Reply

Your email address will not be published. Required fields are marked *