I initially thought "Every Frame Perfect" meant a strict avoidance of any jank or stutter in motion, which I'm fully on-board for but as a film, video and 3D technologist, you're spot on calling out motion blur and similar temporal artifacts. In motion, they not only look 'most correct' to the human visual system, they are the most interpretable.

Adding the correct blur to motion makes it appear clearer but seen as a still, it's obviously not clearer. The nuance is correct motion blur appears clearer while guaranteeing it's as clear as the human visual system can perceive moving details at that speed, so no perceptual detail is actually lost. It's a method that objectively improves perception which only works in motion. If frozen, the method breaks. Thus, evaluating motion blurred stills for clarity or interpretability is incorrect.

The rest of the article focuses on details of proper implementation while missing the opportunity to question whether some of these animations should exist at all. IMHO, motion can be a valuable affordance in limited doses but it's reached a point of overuse and, in some cases, outright abuse of the user's visual field and cognitive load. Designers (and their PMs) see it as a badge of 'Refined Modern UX' but it's devolved into a trendy gimmick aping good design without being good design.

▲

fasterik 2 hours ago | parent [-]

Regarding your last point, I think it's almost always wrong to move something discontinuously, but I do think designers should think a lot more about getting out of the way of the user. A 50-100 ms animation is more than enough for most motions and keeps the UI feeling snappy. Also, animation should be decoupled from input wherever possible. I hate it when I have to sit there waiting for an animation to complete before the app will start acknowledging my keystrokes.

	▲	mrandish an hour ago \| parent \| next [-]
		> I think it's almost always wrong to move something discontinuously Yes, I think we agree. When a thing is becoming a larger/smaller form of itself in a different place, it can be useful to cue the relationship visually with motion. But there are times when the change or displacement is minor enough, I do prefer 'just do it', even when the animation is hyper-fast. It's just more visual/cognitive clutter. It's obviously situational, and if such motion is always very fast, consistent and well-motivated, it never rises to the level of annoying me. I might personally prefer some instances where, if the position overlaps and the size change is minor, just skipping it, but it's not 'bad'. I think the key may be that, done properly, such motion should cognitively be a 'barely there' hint. The moment a state-change animation rises to having perceivable aesthetic value, like being 'pleasing', it's too much. As the senior product owner, I once had a new designer argue that if an animation was as fast as I wanted, no one would be able to appreciate the excellent S-curve ease-in/out. :-) I had to explain if a simple state-change animation was slow enough to be consciously 'appreciated', it had failed in its purpose.
	▲	bfung an hour ago \| parent \| prev [-]
		> waiting for an animation to complete before the app will start acknowledging my keystrokes. Or you find out you can input as the animation happens, but when the animation finishes, you’ve lost where your input ended up and don’t know if you can backspace/delete and retype. (Yes, I’m expressing multiple issues here w/ui & animation & input)