Pulsing Look on Redrock?

[Loren Simons]

Why is it that on my video when im using my 28mm 2.8 canon fd lens it has a sort of pulsing feeling, but when i use my 50 at f/2.8 no pulsing? just curious if anyone has an answer?

 

[henry cho]

not sure why you'd see it with one lens and not another, but a couple of things come to mind... make sure your ground glass spins flat, and put in a fresh battery. extreme shutter speeds will also make pulsing from a non-flat spin more apparent.