Apple tells Ars Technica that it thinks the “jelly scroll” effect some users have noticed on the new iPad Mini is normal LCD behavior that the company won’t have to fix. The effect, also known as skewing, can make it seem like one half of the display is slightly behind the other while you're scrolling, and it’s most apparent while using the iPad Mini in portrait mode. Verge executive editor Dieter Bohn noted the issue in a tweet and in his review of the device published this morning. Despite our requests before and after publishing the review, the company did not respond or comment.
Ars explains that the issue happens because the iPad starts drawing the lines on one side of the screen, and it takes time to go from one side to the other. A tiny amount of time, yes, but it can be noticeable depending on the device.
You can see what it looks like below:
If you want to see how LCD screens refresh in shocking detail, The Slow Mo Guys on YouTube have done a video showing how it works with TVs and iPhones.
Apple is correct in stating this effect is common in LCD displays. It’s very possible that the screen you’re reading this on right now would display the same effect if you loaded up a webpage that tests for it — my laptop shows it quite strongly. The reason it sticks out on the iPad Mini, though, is that it’s frequently used in alignments where the problem is most apparent — it’s not likely to be an issue on a landscape display where you’re scrolling vertically.
This effect also happens with many video cameras, for largely the same reasons: if you pan fast enough, straight items like poles and trees will slant to one side, as the data is read from the top of the camera’s sensor to the bottom.
While the effect is common (and subtle on the iPad Mini, we don’t think it’s a deal-breaker given how good the screen is otherwise and the inclusion of USB-C), it seems noticeably worse on this particular model than other recent iPads. It also feels unusual that Apple isn’t concerned about it while managing to avoid jelly scrolling on both higher-end iPad models and even my previous-generation iPad Mini (which retailed for significantly less than the new model).