Trying to get handle on 720p - 25vs50

[Shooter]

I never have quite got a handle on the difference between 720p - 25/50 despite reading Barrys Book and other references.

Why would I shoot one in preference to the other?

Does it make any difference at Edit stage ie project setting?

[adamdodd]

25 p is real time, 50 p is %50 of real time ( slow motion), try shooting both modes, you will see the difference in playback through your cam..

[Shooter]

I dont think that is correct.

[adamdodd]

Sure it is; 25 progressive frames per second = PAL. 50 = double the amount of progressive frames in a second or slow motion at % 50.

Something you can only do at 720, the overcranking..

[daveswan]

IIRC there is a 720/50p in PAL where the 50fps is genuine, not overcrank, unlike 50fps in a 720/25p stream.
I think it is used for eg sports where you want smooth motion like 50i but with the advantages of prog scan.
I may be wrong, of course!
Dave

[Barry_Green]

No, you're correct.

25P = "the film look"
50P = "the video look" (as does regular PAL, which is 50i, NOT 25fps)

[Shooter]

So Barry - are you saying that the 50p mode is "interlaced progressive" and that creates a video look similar or same as 50i?

@ adamdodd - you are confusing the 50p with framerate

[Barry_Green]

50P is progressive-only. It creates a "video look" that looks similar to, but sharper and better than 50i.

[Shooter]

Thanx Barry - I need to do some tests now.

My camera assistant and I debate this issue everytime we shoot with the HVX so its time to sort it out properly.

Thanx for the info. I had got an idea in my head from your book that the 50p and 60p were broadcast standards EBU

[JitCam]

lets say you shoot something in 50p (video look). when rendering out to mpeg2 dvd, would this 50p footage have to be converted to 50i.. thus making the footage from progressive to interlaced? or is there a dvd standard also for 50p footage?

thanks

[Barry_Green]

lets say you shoot something in 50p (video look). when rendering out to mpeg2 dvd, would this 50p footage have to be converted to 50i.. thus making the footage from progressive to interlaced? or is there a dvd standard also for 50p footage?

thanks

Yes you'd have to convert to 50i. DVDs are standard-def only, and there is no 50P support for standard def.

[JitCam]

ok, thanx Barry!