Can i convert 50i into 24p?

Discussion in 'Camcorders, Action Cams & Video Making Forum' started by JamesP1701, Jan 4, 2012.

  1. JamesP1701

    JamesP1701
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    This may sound terribly noobish. I've just purchased a canon hf g10 and am shooting in 1080i/50i mode.

    I am using Vegas to edit. It seems possible to create a 24p project and put the 50i footage into it but I'm wondering whether it's that simple. I like the more cinematic frame rate that 24p offers.

    Appreciate thoughts

    James
     
  2. grahamlthompson

    grahamlthompson
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    You can but anything with significant movement is going to look horrible.

    Resolution is easy to change, frame rate can be easy or very hard. Converting 25 fps footage to 24 fps involves losing some frames. This is much harder than changing the frame rate to a multiple.

    ie 25 fps to 50fps.

    In any case the filmic look is much more than a frame rate.

    Consider a movie projector, the projector normally has a 3 blade shutter. Initially the shutter blanks the image while the projector pulls down the next frame into the projector gate. The rotating shutter exposes the whole frame in the short time the shutter revolves to uncover the frame, the next blade covers the frame incrementally and uncovers it the same way, repeated again until the next frame is pulled down. The image is totally black for short periods. TV's do not work that way there are no periods when the display is totally black (not for CRT, LCD or Plasma displays)
     
  3. PhilipL

    PhilipL
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    Hi

    In PAL land we would use 25p from 50i.

    Note that 25p from 50i isn't really the same thing as native 25p. You don't get the increase in resolution or the cleanness that native 25p (or 24p) provides .

    On a progressive HD TV 50i is de-interlaced to give you 50p (this for the same reasons is not the same as true 50p), so you keep the temporal information and get smooth movement, i.e. the video look. To convert that to 25p you are essentially doing the same thing in the software but then throwing away every other frame. Unless you have shot with this low frame rate in mind, it will look juddery and be hard to watch.

    Regards

    Phil
     
  4. chrishull3

    chrishull3
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    25P is what frame rate i would use with your G10 when filming.
     
  5. doug_1986

    doug_1986
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  6. axiomprime

    axiomprime
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    You can get it to 25fps easy enough and then run it slow. That's the only way to do it without fudging frames. I don't see any benefit to 24fps over 25fps unless you plan on running it on an old 35mm movie projector in a cinema.
     
  7. grahamlthompson

    grahamlthompson
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    The advantage of 24fps is it's the only full-HD progressive format you can burn to blu-ray. To be any real use you need a camcorder that can record 1080p24 natively.
     
    Last edited: Jan 7, 2012
  8. rogs

    rogs
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    As the guy says in the Vimeo '24p conspiracy' video linked to above -shoot for what you like to see, not what someone tells you is 'right'.

    Because both my computer monitors are 22", and my TV is an 'HD ready' 37" plasma, I have absolutely no reason to view video as 1080. 720 is the optimum for the above screen sizes.

    It just so happens that 720p at 50fps is also a 'Blu-ray' compatible format -and the 50fps gives me the kind of motion 'smoothness' I've been used to with common or garden 50i footage, but without any of the interlace artifacts.
    So it suits me.

    Related to the 24/25fps point that axiomprime makes-- I have found is that, even though my WD media player and plasma TV can play back progressive videos recorded at 24fps (or more usually 23.976fps) there is definitely evidence of slight 'stepping' on long smooth pans, on my PAL TV. Which I hate!
    Speeding those files up to 25fps (and the audio as well of course!) solves that problem.
    So I would argue that, in PAL land anyway, 25fps is a better solution than 24fps......or ,IMHO, 50fps - even at the reduced resolution of 720 - is even better, and gives me the best display, to suit the kit I currently use....
     

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