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25p official topic, aka Don't cry for me Argentina
  • 236 Replies sorted by
  • MimirsanMimirsan
    Bloom was mistaken with 25p...he later realised.
    I think folks should for now just accept that full on native 25p wont happen anytime soon.
    VK's great but he aint a miracle worker.
    Im guessing some things can be hardware related or require extensive access to certain parts that he may not be able to.
    If anyone is to be asked about taking action with 25p... its Panasonic...and these are the fuckers who dont listen to customers or release new firmware with worthwhile updates.
  • alcomposeralcomposer
    2 questions... is there any chance 25p can be output over HDMI?
    Is the sensing frequency 'hard wired' to the chip through modes?

    I am guessing that the 25p hack simply combines 50i? (which is not the worst thing is it?) One would have to question how the AG-AF100 does 25p?? Maybe thats just deinterlaced 50i??

    Maybe we all have to just get the AG-AF100 :-(
    Maybe we should all wait to see what VK has been able to put together in 61... If anything this project has shown : when there is a will- there is a way...

    Lets keep our spirits high!
  • pkramerpkramer
    So, who would like to swap for my gh1 hacked? :) it worked in 25p.
  • MimirsanMimirsan
    "Maybe we all have to just get the AG-AF100 :-( "


    Thats exactly what Panny wants you to do...resist! lol

    I still have a lil red GH1 ;-)
  • PhilMyselfPhilMyself
    Well if the AF-100 wasn't so expensive, i would buy one.
    For Pal users, this is really a bad news. I'm so disappointed...
    In fact I'm thinking of selling all my GH2 stuff and get a 7D !
  • stolpis100stolpis100
    I am now considering the 'Emergency Back-Up Plan'. ie shooting 720p50 then interpret the footage as 25p in premiere pro, and speed it up 200% to get normal speed again. I did an entire shoot like this on the 7D about a month ago and it worked fine, plus I had the option of slowmo when desired. My questions about this plan are:

    1. I am still slightly unsure how the whole 720p in a 1080i wrapper thing works. Are we getting a true progressive 1280x720 image here?

    2. Can I still use the whole range of shutter speeds?

    3. Are we going to see a good enough increase in the available bitrate in this mode so that we can get anywhere near matching 1080p24?

    On a side note, if 1080 is urgent, upscaling 720p to 1080p is not too bad and especially so if you are using an a plugin such as InstantHD.

    This workflow is far more efficient than any speed changes and all the inherent irritants that come with it.
  • _gl_gl
    @ stolpis100
    1. 720p on the GH2 is true progressive, not wrapped in anything.
    2. yes, except 1/25 isn't available as it would be slower than the frame rate (well, except in manual focus mode, but then it halves the framerate).
    3. I'm sure V. will be able to increase bitrate, but you can't make up for resolution loss. 720p has less than half the res of 1080p.
  • MimirsanMimirsan
    Looking at current batch of hacked 720p footage on GH2 it looks very very nice with lots of detail...way beyond GH1s...and way beyond 1080p on Canon dslrs. ;-)
    This is why I aint selling my GH2...just yet ;-)
  • alcomposeralcomposer
    Mostly everything on commercial TV (sitcoms) are shot on 24p...
    Lets all get behind the next hack and test it to the limits!
  • stolpis100stolpis100
    @_gl thanks, and I assume as you can shoot at 50fps, there should no negative flicker issues when shooting under 50Hz lights?
  • _gl_gl
    The problem flicker is caused by the shutter speed, so you have to use a multiple of the mains frequency - 1/50 or 1/100 works for me (faster doesn't).
  • ItsguyItsguy
    Some in this thread have claimed that it is 'impossible to tell' when footage has been conformed 24 to 25 by speeding up 104%. I'm afraid this is simply untrue and it's best to be clear on this point.

    While using, for instance, Cinema Tools to conform to 25 and just letting the audio run at a higher pitch does product a very good quality conform requiring no interpolated frames, the result is very different from the original. I have made several professional films with a 24p web version and a 25p DVD version shot on GH2 - in this case the DVD was very much secondary. While you might get away with this, be warned the emotional tone is very different, and some scenes lost all their 'weight'. Fast talkers became quite comical and very unnatural. Re-pitching, as suggested above, sounded noticeably processed, and in some cases it was better just to let it run at a higher pitch.

    None of this was at all satisfactory to me as a director. Please, let's hear no more of this 'indistinguishable' talk. With all due respect, could those that can't tell the difference please accept that others very much can and leave it at that, debating this issue is quite unhelpful.

    In the meantime, 1080p50 via HDMI to a decklink HyperDeck shuttle??? That sounds like the grail at this point... Is there any chance of something like that?
  • stolpis100stolpis100
    @_gl I was under the impression (well according to @madact explanantion on this thread a day or so ago) that provided you are running at either 25 or 50 frames 'if your shutter fires 25 (or 50) times a second, you can use any shutter speed you like, because it will always 'open' at the same point in the ripple and 'close' at the same point in the ripple.'

    Have you come up against this not being the case in real world testing?
  • alcomposeralcomposer
    I totally agree with @Itsguy
    However- the only 'light at the end of the tunnel' is that even considering we NEVER get 25p- (which I believe 50p is som sort of solution) the Blu-Ray spec is VERY adept at 24p and web distributed content is only becoming more important. Also- can I get ANY info from people involved in low/no budget films which have to take into account small cinema release; web; blu-ray, & Pal TV? What sort of professional workflow occurs here? (Some demonic frame reinterpreting?) I doubt that when Pal TV shows Star Wars they simply speed it up? Or do they?

    EH!
  • alcomposeralcomposer
    I know that this may not be the best place to put this: but this pertains to 1080p25 HDMI:

    The Hyperdeck Shuttle only does:
    720p50, 720p59.94, 720p60, 1080i50, 1080i59.94, 1080i60, 1080PsF23.98, 1080PsF24, 1080PsF25, 1080PsF29.97, 1080PsF30, 1080p23.98, 1080p24, 1080p25, 1080p29.97, 1080p30.

    Sorry @Itsguy.. there is no 1080p50 (only i) :-( I wish it wasn't so... But for more robust HDMI- The Atomos Ninja is probably better- being in ProRes (so you can record without filling up a HD in 7 mins etc)... YMMV
  • stolpis100stolpis100
    @alcomposer I have 2 examples.

    I made a low budget doc/movie. Was shot in the UK at 25 frames. It did quite well at a film festival, on the back of that it got released on DVD in some territories. In Canada, it received a 'demonic' conversion to NTSC along with a complimentary aspect ratio cockup. No cinema release however.

    I recently made a commercial, was shot on a Red at 25p. This has subsequently been given a release in cinemas and I had to painstakingly retime every edit with the footage reinterpreted as 24p. Had I known it was destined for the cinema I would have shot 24p in the first place.
  • Ian_TIan_T
    @itsguy:

    I'm sorry to disagree...but "indistinguishable' is in the eyes of the beholder. You as the director will be more intimate with your product or 'baby." Being a musician I know too well about this. Just like the old adage "you are your own worst critic" in this case "you know your baby better than anyone else." But to the "outsider" or the average viewer they can care less. They would not know a 4% sped up footage from an original (in most cases IMO). They'll only notice if you do side by side comparisons (sort of like _gl's experience with Frazier). You notice even in _gl's experience he only noticed Frazier's voice difference "after" he watched an interview with Chesley Gramer (sp). If the show was pitch corrected (to sound like his real voice) he (_gl) might have continued to watch in ignorant bliss. :)

    If someone messes with my baby...I'm gonna know better than the next guy. But the next guy wouldn't know a thing. Often times people "conform" to something new. Vitaliy (in another thread) posted a YouTube video documentary on video editing. You'll see Steven Spielberg (among others) in one excerpt commenting on "this generation" as opposed to "his generation" being used to quicker cuts and fast action etc. To the older generation it might be confusing...but to the "MTV" generation they loved it (or was used to it). Most of us here are technical folks...so we'll know when something is technically wrong. But I can't imagine most PAL viewers (non technical) can see the difference. I could be wrong though (that happens quite a bit) :)
  • alcomposeralcomposer
    @stolpis100

    So basically either way we are 'sc@$ed'.

    Not that I didn't know that- its just that one does forget that its 2011- and really once you capture something in the can- you want that to have some sort of bulletproofness... not fall down the minute you go from 25-24-25... :-(

    Nice... Don't really know how much of an issue this 25p is in relation to the reality that if shot in 25p - going down to 24p is just as gnarly...
  • alcomposeralcomposer
    Anybody watch the 'editing doco' VK put up... ??? FANTASTIC quote from James Cameron:

    James:
    "Hey guys- Terminator 2 is running a bit long- and I like the edit- I don't want to touch it any more! Can we take out every 24th frame? Every second? That will make it 1/24 the total length shorter!!!"
    Editor:
    " "
    James:
    "Yeah lets do it"
    Editor:
    " cut cut cut cut cut"
    James:
    "wow, wow, what are those strange motion judders - and the strange timing - what's going on.!"

    Anyway, not that this helps but love the doco VK! Good find!
  • _gl_gl
    > You notice even in _gl's experience he only noticed Frazier's voice difference "after" he watched an interview with Chesley Gramer (sp).

    You weren't paying attention, I noticed as soon as I saw a US rate version of the show, and it wasn't just the pitch but also the speed of conversation.

    But you're right, most people won't notice, and as I keep saying it depends on what you shoot - but if you shoot a high-quality movie with music and lots of careful emotional staging (through both visual, post/grading and audio), you want it to be perfect _before_ it gets mangled. Every damaging compromise adds up, and sooner or later that lack of overall quality or care will come across to Joe consumer, even if he/she can't tell you what exactly the problems are. Or to put it another way, they simply will not feel how you wanted them to feel, so you've damaged your own project.

    I could equally say, Joe Consumer will never tell the difference between 24mbps, or anything higher - and yet we still care about getting a higher bitrate from the hack. So if you're here because you'd like to see these improvements, just deal with the fact that some people want 25p in the same vein and move on.
  • ItsguyItsguy
    @alcomposer - thanks for putting me right on the HyperShuttle, pity!

    @Ian_T - I take your point, but it's something of a truism to say that they won't see the difference if they have only seen one version. If you have only ever tasted instant coffee or seen fake diamonds then you wouldn't know there was any difference either, but that would hardly mean there was no difference. I want my viewers to get a particular emotion, and when I watch someone else's film, I want to feel what they intended too. It's not too much to ask, and again, 'indistinguishable' is simply too big a claim. How are we to persuade Panasonic to make a GH3 with 1080p25 if people at the sharp end keep repeating that it doesn't really matter? This is why I say it's unhelpful, even if it weren't for the deal-breaking issues of mixed multi-camera shoots, music videos and strobing lighting.
  • _gl_gl
    @stolpis100, I haven't really shot 50i beyond short tests, but I see pulsing on the camera monitor in all shutter speeds except 1/50 & 1/100. If I get time I'll check out recorded footage, but I'm sure someone here has already done that?
  • stolpis100stolpis100
    @_gl are you based in 'PAL-land'? Would definitely be very interesting if you do get a moment to compare the different shutter speeds. Maybe the camera monitor refreshes at it's own unique rate which doesn't directly correspond to the resulting footage?
  • _gl_gl
    Yep, UK/PAL. Just tested it up to 1/4000, with a white sheet of paper under incandescent lighting (halogen @ mains freq) and a high-frequency driven fluorescent tube:

    24p: 1/25, 1/50, 1/100 are the only good ones.

    50i is interesting:
    - you do get a 1/25 & 1/30 shutter options - strange, why?? I can understand 1/25 as it just effectively halves the framerate to give you 1/25p - but why 1/30?

    - anyway all speeds between 1/25 and 1/100 are fine.

    With incandescent:

    - most speeds up to 1/320 are fine, although I can see very slight selective darkening on some of the higher speeds (but it's so subtle you'd never notice it on a normal shot)
    - past 1/320 you get clear darkening, possibly from the rolling shutter

    With the high-frequency fluorescent tube however:

    - from 1/125 onwards you start seeing a rolling bar that gets worse as the speed goes up.

    So that's another problem, not all lighting is driven directly at mains frequency.

    Anyway, running at a mains-frequency multiple frame rate (or a cleanly divisible one like 25p) does gives you more shutter speeds to choose from - so another good reason for 25p.
  • stolpis100stolpis100
    @_gl wow, thanks so much for checking those out those speeds. On the back of these findings I think I may take the plunge and pick one up next week and then hold out to see how high the bitrate can get. Thanks again!
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