Personal View site logo
Make sure to join PV on Telegram or Facebook! Perfect to keep up with community on your smartphone.
25p official topic, aka Don't cry for me Argentina
  • 236 Replies sorted by
  • andresandres
    Sad Sad news, hope the 1080 50p si posible, on the other way, I just got a gh1 instead of the gh2, so for me is not that bad.
  • MimirsanMimirsan
    Well off to sell my GH2...toodles!
  • Vitaliy_KiselevVitaliy_Kiselev
    >1080 50p is posible

    Looking at sensor setup I don't think so.
    GH2 sensor speed looks almost the same as in GH1 (G2 is slower).
  • Vitaliy_KiselevVitaliy_Kiselev
    >Well off to sell my GH2...toodles!

    :-)
  • MimirsanMimirsan
    Well might give the next Ptool a go first...Im a bit of curiosity whore lol
  • _gl_gl
    > 50 FPS divided by 2 equals 25 FPS. That would work just as well if not better.

    Right it's better because you have a choice between 50p and 25p from the same footage - the downside is that you loose the 1/25 shutter speed option for low-light (or dreamy blur).
  • _gl_gl
    > frazier is shot 24p on 35mm right? but we dont know what it is cut to. i assume it would be cut at 29.97 because of part durations needing to be exact.

    Not sure, but part of the reason for shooting 24p could have been the easier conversion to PAL without horrible pulldown, so I would assume it was cut on 24p and then conformed.

    > i dont remember ntsc>pal conversions having a duration change, so there shouldnt be a pitch shift, or speed shift between american and english versions,

    Yes there was - see Wikipedia: http://en.wikipedia.org/wiki/PAL_speedup#576i_speed-up

    "Motion pictures are typically shot on film at 24 frames per second. When telecined and played back at 576i25's standard of 25 frames per second, films run 4% faster. This also applies to most TV series that are shot on film or digital 24p.[2] Unlike 480i30's telecine system, which uses 3:2 pulldown to convert the 24 frames per second to the 480i30 frame rate, 576i results in the telecined video running 4% shorter than the original film as well as the equivalent 480i30 telecined video."

    "Depending on the sound system in use, it also slightly increases the pitch of the soundtrack by 70.67 cents (0.7067 of a semitone). More recently, digital conversion methods have used algorithms which preserve the original pitch of the soundtrack, although the frame rate conversion still results in faster playback."
  • _gl_gl
    @Mimirsan, give V. a chance, maybe 50p can be made to work.
  • LPowellLPowell
    Vitaliy said:
    "GH2 don't have 25p mode amongst sensor setup modes.
    24fps, 50fps, 60fps, 120fps, but no 25fps."

    It seems the hacked GH1 will remain the best solution for PAL 25p recording purposes. The best results I've obtained are with the 100Mbps Max Latitude Native 24/25p Patch:

    http://www.personal-view.com./talks/discussion/162/100mbps-max-latitude-patch-v2-updated-for-ptool-3.55d#Item_23
  • stipstip
    I'm trying to understand but I don't.
    Is 25p for GH2 ruled out now or not?

    > In upcoming PTool you'll see quite stable 25p, but. It only has first field in top part, below is garbage.

    So despite the sensor not having 25fps setup there will be a 25p option - but it won't work. Will it never work or is there a chance that it can be fixed?

    I'm confused?!
  • MimirsanMimirsan
    @_gl
    I was kinda joking! ;-)
  • _gl_gl
    Oh : ).
  • Mark_the_HarpMark_the_Harp
    Silly question but can 1080i 50 be made any better?
  • madactmadact
    Mmm, of course, rolling shutter, just another thing to worry about :oS well, we should get global shutter on the sensor by GH3 or GH4, right? ;o) Well, I suppose if you're pegging out for a GH2 and some nice shallow DOF glass a couple of cheap hardware store floods, PARs and a fresnel won't break the bank...

    Shame about the sensor modes - I take it 1080 at 50 & 60 is only "i" from the sensor, but any lower frame rate or res will get "p"?

    As for making 50i better, I'm sure it's possible - the techniques twixtor uses should be very applicable, I don't know if they do an i-to-p conversion (haven't played with their stuff), but if they don't, they should...
  • Mark_the_HarpMark_the_Harp
    @madact I was thinking more in terms of in-camera, ie higher bitrate for 1080 50i if we can't have 25p. Or is 1080 50i basically never going to look that good whatever you do with bitrate?
  • madactmadact
    @Mark_the_Harp It's a two edged sword... less flicker, better motion, in theory, but ugly jaggies on verticals when panning...

    Personally I hate it as it makes computer vision algorithms more complicated, and for watching video, most computer playback software seems to update both fields at the same time X-P . OTOH you tend not to notice it on TVs as they're designed with interlacing in mind and do it properly.

    I don't really have personal experience with modern TVs though, I stopped watching broadcast / cable years ago and these days all my media is viewed via projector on a 120" screen :o)
  • Mark_the_HarpMark_the_Harp
    Can't argue with any of that! Just seeing what the best solution is for those of us using the GH2 who have to do 25p.
  • MimirsanMimirsan
    Best solution would be high bitrate 50i FSH and deinterlace...second best 720p 50p SH to 25p

    As long as mudbreakup issues are hopefully sorted via bitrate increase...all will be pretty good
    Prem pro does well with deinterlacing.
    Less of a headache than 24-25p conforming.

    50i high bitrate looks great on hacked GH1...25p native has a very slight improvement...but cant figure why.
    On the hacked GH1 50i was more stable at highest bitrates than using the 25p native patch.
  • thecranethecrane
    Can the 24p mode be modified to 25p at all ? Or is that limited due to the way its hardcoded in the camera ?(probly because of no sensor setup for 25p as previously stated by V) It would be a fantasy if people could sacrifice 24p mode for 25p.
  • Mark_the_HarpMark_the_Harp
    @thecrane That might be the case although I actually like 24p for when I'm just hosing around doing home video of the children or whatever. But only because it has more detail and it's quite fun to take the odd still off it. Just wish I had that same quality at 25/50!
  • mrbillmrbill
    @Ptchaw - I'll repeat what I said before - if you're originating footage for a programme for ANY terrestrial broadcaster in the UK, you CANNOT conform from 24p to 25p. Please do not assume I don't know what I'm talking about, because post-producing for broadcast has been my day job for over 20 years. Feature films are often sped back up, but you'll see all kinds of motion artifacts (24 to 25fps pulldown cadence, where a field is added every 12 frames to make up the numbers). Speeding up footage by 4% in a non linear editor often results in motion smearing and other artifacts.
    Every programme submitted to a UK broadcaster which has been edited by an independent post house is subjected to the most rigorous tech checks imaginable, and a 24-25fps conform would never survive this process. This is without starting to mention stuff like not shooting at native mains frequency to avoid light flicker and so on. So whilst the 24-25 conform workaround might work for you, it doesn't work for me, and I can't imagine why you're so negative towards a whole bunch of people who'd like to use the camera in this way. You don't need it? Fine - but don't deny us the opportunity to request 25p on these forums.
  • Donnie88Donnie88
    Wow...so is that it? No 25p for the GH2 then?

    Is this confirmed?
  • _gl_gl
    > GH2 don't have 25p mode amongst sensor setup modes.

    @V., is it possible you can add new sensor modes, or modify the 50p/i ones for 25p? I assume these modes are just a collection of timing/windowing parameters?
  • Donnie88Donnie88
    @stip

    "I'm trying to understand but I don't.
    Is 25p for GH2 ruled out now or not?

    > In upcoming PTool you'll see quite stable 25p, but. It only has first field in top part, below is garbage.

    So despite the sensor not having 25fps setup there will be a 25p option - but it won't work. Will it never work or is there a chance that it can be fixed?

    I'm confused?!"


    That's exactly what I'm trying to figure out.

    So the 25p option will be there, but it won't look good?
  • fehafeha
    If I remember right, Philip Bloom had a pre-production GH2 and had 25p, later on was complaining about it's removal in production stage , so was it firmware or hardware change ?
Add a Comment