33.33 frames per second

[Daniel Anthony Porto]

Hey Im an old member that cant log into his account...

 

Excuse my ignorance but can anyone explain the maths behind this number in terms of flicker? In particular I want to know how you can get .3 of a frame... how can you capture anything but a whole frame?

 

Wanting to do a speed ramp most probably with a 435 and RCU but if there are any digital options :p

[David Mullen ASC]

You capture whole frames but your frame rate might not allow a whole number of frames to fit within a second. Imagine shooting 24.5 frames per second, so in two seconds you would have captured 49 whole frames.

 

33.33 fps means almost capturing 100 frames every 3 seconds. Think of it as the frames being whole but the time being fractional rather than the other way around.

[Daniel Anthony Porto]

Hmmm still don't entirely understand. But basically when comparing capturing and projecting at 24fps for one shot and capturing and projecting at 25fps for the other, there is not going to be much difference, correct?

[David Mullen ASC]

33.33 fps just means that the camera is running slightly faster than 33 fps, so if you had a stopwatch and were super fast, if you stopped the watch exactly at 1 second, the camera would already be in the process of taking its 34th picture rather than having exactly finished taking its 33rd picture.

[Daniel Anthony Porto]

ok.... correct my understanding if I am wrong but if you shoot at 1fps the camera will capture that one frame for the whole 1 second, and 24fps will do exactly the same but capture 24 frames in 1 second.

[David Mullen ASC]

Yes, 1 fps means one frame per second, and 24 fps means 24 frames per second. With a 180 degree shutter, the film is being exposed for half that time, so at 1 fps, the frame is exposed for a 1/2 second.

 

You have to stop thinking of the second as a physical thing, the frame captured is a physical thing, and the movement pulls that film through intermittently at a certain speed. If a whole number of frames fits within the time demarcation of 1 second, great.