
This first rotating box, is animated on 2's - it's 4 four frames and revolves 1/2 turn but ... this strobes quite violently... mainly because it's essentially just 2 frames... a diamond, and a square - that's all the eye is seeing, however, the internal sections give the impression of a full rotation because of the blue and white sections.
Now look at this...

This is animated on 3's - it's 1 additional frame above the previous example at 5 frames and also rotates 1/2 a turn... it strobes also but reads better as a spinning square because the eye interprets the form differently and therefor it reads better.
yep...kudos for that post baccaman, that is something that one learns almost intuitively trough simply much time of animating...so it's hard to put it into such simple terms

here's an example of it going on in a hell of a classic game...

(with only 2 real frames)...guess...and you get a spankin brand new hand watch

PS: Wolverine very very =/= baccaman, Wolvie is just a guy who's good at drawing and pixeling, Baccaman is a pixer who was doing his thing before many of us were born and has even sticked to the pixels troughout this polygonated age.....and is NOT disgruntled, how unique is that?

(I wonder how many actually get the refference c.c)