Why iPhone doesn’t have ProMotion
So before the launch, there were many people speculating that the new iPhone will get ProMotion, I said no so a bunch of idiots were laughing at me saying they’ll be proven right in a few hours….
Here’s the thing, bigger numbers are not automatically better, there’s this thing called diminishing returns, sure 90hz will be slightly better, but that was never the question, rather, is the tiny improvement in smoothness worth the reduced battery life?
If you have used the new iPad Pros, you might think ProMotion is a big thing and not just “slightly smoother”, and you’re not wrong, you might now know this but…
Refresh rate at which an animation appears smooth is **relative to screen size and viewing distance.**
That’s right, it depends on screen size, much like how “retina” resolution depends on these things, because if you think about it, they’re fundamentally the same thing.
Imagine we have a video of something moving across the screen at a rate of 1% width per frame. If this plays on a TV, that will translate to 1CM of movement per frame, which may appear to be not smooth at all, since you know, it skips 1CM at a time, with no transition in-between. But if you play the same animation on your Apple Watch, it will be incredibly smooth since it’s only moving fractions of a millimetre per frame. That’s basically the gist of it, obviously it also depends on viewing distance, if you watch that TV from 100meters away, you won’t even be able to resolve 1CM on the screen with your eyes and it will appear perfectly smooth.
It actually also depends on the speed of the animation, yes so if you need for example the control centre to scroll up within 1 second on an iPad, and you only have 60 frames to do it, that means the edge will jump 2.5mm per frame, where as if you can do it in 2 seconds, you’d only be jumping 1.25mm per frame, which will appear more smooth at the same refresh rate, same screen size, and same viewing distance.
Knowing all of that, why did Apple choose to put ProMotion on iPad first? Well there are several reasons:
1. It has the largest performance headroom, you get a huge battery compared to an iPhone, and you get high performance custom chip compared to Macs.
2. It’s often viewed from a close distance, about the same as an iPhone, but much larger.
3. It’s gesture controlled, so animations must play as fast as your finger is going across the screen.
4. Apple Pencil.
All of these factors just mean it’s the ideal platform to introduce ProMotion. There’s no reason to introduce it on iPhone because relatively speaking, considering the size of the screens, iPhone is already “ProMotion”. Like I have already mentioned, at the same viewing distance and animation speed, half the screen size means you only need half the refresh rate to get the same smoothness.
There’s also the issue of the OnePlus and other Android phones using 90hz displays, and getting great reviews. First of all, we cannot deny there will be some improvement with a higher refresh rate, and there will be some degree of confirmation bias. As far as I know, nobody has done a blind test to see if 90hz gives a very noticeable improvement.
One must also understand that the experience of fluidity in touchscreen interaction is NOT only determined by frame rate, it’s a combination of frame rate, input latency, and even the software. iOS consistently has had less input latency than Android, and this could mean that increased refresh rate on Android is more effective than on iOS. This is simply because reduced input latency is less obvious, if you already have low latency. It could be the case that Android devices have a latency that is just a bit higher than noticeable, which can be further reduced to below the noticeability threshold simply by increasing frame rate. This would be ineffective on iOS since the latency is already lower than that noticeability threshold, without using high refresh displays.
Android manufacturers can’t fix Android’s latency problems, they can only reduce frame rate induced latency, by using high refresh displays, even if that drains battery. Fortunately for them, 90hz is a big number you can advertise and add to the spec list. So even if they had other ways to reduce latency, they would favor the high refresh rate display route, because it’s a bigger gimmick to sell.