24P SYSTEM: 24PsF or 60i

Michael B. McGee

Michael B. McGee

Well-known member
hey guys and gals,
i just updated/upgraded my ex1 to the 1.11 firmware and noticed in the Video Set menu at the bottom i have a new option: 24P SYSTEM. my choices are 24PsF or 60i. what do these mean?

thanks as always.

-mike
 
It probably let you choose whether to add pulldown to the 24 frames or just use them as is, ala 24pN mode on the HVX. I would just go with 24PsF
 
With PsF, a progressive frame is sliced into two "segments", with the odd lines in one segment and the even lines in the other segment. This allows for a progressive picture to be processed through the same electronic circuitry that is used to store, process and route interlaced video. Technically, progressive segments are equivalent to interlaced fields, but unlike native interlaced video, there is no motion between the two fields that make up the video frame, both fields represent the same instant in time.
PsF technique is similar to 2:2 pull downhttp://en.wikipedia.org/wiki/Telecine#2:2_pulldown, which is widely used in 50 Hz television systems to broadcast 25 fps progressive material, but is rarely employed in 60 Hz systems as there is very little content of progressive 30 fps material. 2:2 pulldown scheme had originally been designed for interlaced devices, so fine vertical details are usually filtered out to minimize interlaced line twitter. PsF has no such filtering.


PsF has been recognized http://en.wikipedia.org/wiki/Rec._709#Frame_rate as a legitimate way to transport progressive frames within an interlaced system. 25PsF and 30PsF rates have been added to the specification in addition to the more established 24PsF. "Fractional" frame rates, having the above values divided by 1.001, are also permitted, which results in 23.98PsF and 29.97PsF rates, currently used in 60 Hz systems.


And 60i is just that, 6o interlaced
 
JD - Just to clarify in my head - If you have time to answer this:
When using PsF does the camera sensor capture a progressive image, and then record it an interlaced image, field and field makes one frame? Is the frame ever recorded or displayed as a progressive image? Or is the frame displayed interlace if that is what you treat it as in the editing software or as progressive if your editing software can put the frame back together?

Thanks!
 
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The 24p system setting is for the output of the camera. If you are recording to memory cards inserted in the camera it still records the regular "native" way if you are set to recording in 24p HQ mode.

If you are outputting via HD-SDI or component (or composite) this is what's affected by the 24p system setting.

60i has pulldown added. Its signal is standard 60i. It looks like 24p footage to a viewer but it is 60i to the playback system. If you shoot to the memory cards (SxS) in-camera with SP mode this is how your video is recorded.

24PsF allows for true progressive footage out of the camera. It's the same system the DVX100 uses as well as the Canon HDV cameras' 24F mode (XH-A1, etc.). The benefit is you can put progressive footage on a Blu-ray disc or DVD and save on compression. Upconverted 24p DVDs also look better on HDTVs than upconverted 60i footage does, at least from my experience.

Googling "24psf vs 60i" will net you more explainations on the subject. Or this Wikipedia page: http://en.wikipedia.org/wiki/Progressive_segmented_frame
 
Just to get this straight: If you record to SxS or SDHC with system mode set to 60i, the card is recorded at 60i (interlaced 24p with pulldown added)? It would be nice if the card was recorded at the the normal 24psf (actually 23.976) as in the past firmware, but output 60i with pulldown for the purpose of client monitoring on standard 1080 60i HDTV's with component, SDI 60i for higher end monitors. Lower cost with HDTV's and giving the actual look of pulldown added, the way most will see it when broadcast/cable, etc., for the client.

Is this how it works, or will it record 60i to the card? Not what I would want, I require 24psf.

Thanks
 
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