720/50p and 720/25p?
- Thread starter Shooter
- Start date
Josh Wallace
Member
What is the difference between 720/50p and 720/25p?
This is definitely a bit of a confusing one, and there is a lot of misinformation going around on the topic. Barry Greens book gives the best explanation I've seen but it's still a bit hazy.
I'm only just getting my head around it, but as far as I can tell, the fundamental differences are these;
720/50P always records 50 frames per second no matter what your frame rate is set at. You can shoot variable frame rates or at 25fps but it will duplicate frames and flag frames and still be recording 50 frames to the card every second even if you're only shooting at 12fps.
As long as you have set the User Bits to Frame rate in the camera; an NLE will recognise the flagged frames and discard duplicates to play your footage back at the speed you intended. ( Frame Rate conversion )
I do not really see the point of 720/50P as a capture format. It is always chewing up the maximum amount of space on your card. I never use it.
720/25P is essentially the same I think, but it is only recording 25 frames every second and if you shoot at a higher frame rate it adds more frames.
This makes a lot more sense than 50P, but still the only time i would use this is if I want to shoot off speed and record sound - which is the one disadvantage of 720/25PN.
Otherwise I always use 720/25PN. It only records the actual frames you have set in the frame rate setting - maximising card space, and enabling playback at the desired frame rate in camera.
How does does this affect post prod?
Quite a lot depending on your post workflow! So far the only way to edit any of these formats ( I use FCP Studio ) is by using P2 Logs pass through filter which exports them to XML and does some trickery make FCP see them as 720/50P, or at least it uses the 720/50P Quicktime codec to enable editing in FCP.
Why for example does Cineform HD Aspect not have a preset for 720/25p in PremPro 2?
Don't know.
Hope that helps somewhat. Good luck.
This is definitely a bit of a confusing one, and there is a lot of misinformation going around on the topic. Barry Greens book gives the best explanation I've seen but it's still a bit hazy.
I'm only just getting my head around it, but as far as I can tell, the fundamental differences are these;
720/50P always records 50 frames per second no matter what your frame rate is set at. You can shoot variable frame rates or at 25fps but it will duplicate frames and flag frames and still be recording 50 frames to the card every second even if you're only shooting at 12fps.
As long as you have set the User Bits to Frame rate in the camera; an NLE will recognise the flagged frames and discard duplicates to play your footage back at the speed you intended. ( Frame Rate conversion )
I do not really see the point of 720/50P as a capture format. It is always chewing up the maximum amount of space on your card. I never use it.
720/25P is essentially the same I think, but it is only recording 25 frames every second and if you shoot at a higher frame rate it adds more frames.
This makes a lot more sense than 50P, but still the only time i would use this is if I want to shoot off speed and record sound - which is the one disadvantage of 720/25PN.
Otherwise I always use 720/25PN. It only records the actual frames you have set in the frame rate setting - maximising card space, and enabling playback at the desired frame rate in camera.
How does does this affect post prod?
Quite a lot depending on your post workflow! So far the only way to edit any of these formats ( I use FCP Studio ) is by using P2 Logs pass through filter which exports them to XML and does some trickery make FCP see them as 720/50P, or at least it uses the 720/50P Quicktime codec to enable editing in FCP.
Why for example does Cineform HD Aspect not have a preset for 720/25p in PremPro 2?
Don't know.
Hope that helps somewhat. Good luck.
Last edited:
Josh Wallace
Member
No worries mate.
I'm not sure what Cineform Hd is, but I know that most if not all of the Editing systems in PAL world have not offered 720P support yet. Apple has just announced a Final Cut upgrade that will be out in a few weeks, that will enable native 720/25P ( Not 720/50P ) editing.
I got one of the first HVX's back in about April I think. Done quite a few jobs with it in the last month or two which has really accelerated the learning curve.
I've just kitted it up with the full P2 field offloading station - Powerbook / P2 Store etc, now I've just got to convince some Production companies that it is a viable and user friendly workflow!
I'm not sure what Cineform Hd is, but I know that most if not all of the Editing systems in PAL world have not offered 720P support yet. Apple has just announced a Final Cut upgrade that will be out in a few weeks, that will enable native 720/25P ( Not 720/50P ) editing.
I got one of the first HVX's back in about April I think. Done quite a few jobs with it in the last month or two which has really accelerated the learning curve.
I've just kitted it up with the full P2 field offloading station - Powerbook / P2 Store etc, now I've just got to convince some Production companies that it is a viable and user friendly workflow!
Barry_Green
Moderator
It's for recording live action stuff, like sports or news. Looks fantastic when shot at 50fps and played back at 50ps, a total "looking through a window" experience.Josh Wallace said:
No, you're describing 720/25pN. 720/25p works exactly the same way as 720/50p does; it's there because you can only select variable frame rates in FILM CAM mode, so if you wanted to shoot the 25fps look in VIDEO CAM mode you'd need to use this mode.
David Newman
Well-known member
It does have a 25p preset for 720p, it is called "Aspect HD 1280x720 p25". Of course you can create any needed presets, it is all very configurable. Are you confusing "Aspect HD 720x576p50" and wondering why there is no "Aspect HD 720x576p25", because that is standard definition. 
Aspect HD can do SD, we just didn't market it for that. You can create SD projects/presets also.
Aspect HD can do SD, we just didn't market it for that. You can create SD projects/presets also.
Last edited:
Josh Wallace
Member
Aaah, so i had that a bit back to front. Thanks for the clarification Barry.