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Canon c300, 24Psf?


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#1 Paul Yee

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Posted 28 February 2012 - 11:09 PM

I have technical question about the HDSDI output on the Canon c300. I often work as an operator for a live streaming concert series. I recently purchased the c300 and brought it in to our venue to see if it was compatible with our switcher system (not sure the details of the model switcher). The switcher was unable to recognize the camera and we eventually realized that it is because it was set to receive a 24Psf input and the Canon c300 only outputs a 60i image from the HDSDI. Not sure why the switcher has to be in 24Psf but the sony EX3 (which we shoot the shows with) and F3 can both output that framerate from the HDSDI.

So my questions are....
1. Am I definitely correct that the Canon c300 can not output a 24Psf signal from the HDSDI?
2. Is that something that can be added with a firmware update?
3. Is there an external accessory that can convert 60i to 24Psf? I have found a few frame rate converters online but they are all north 10,000$


I spent a good amount of time on the phone with Canon Tech Support and actually couldn't get solid yes or no answers on any of these questons.

Paul
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#2 Kevin Burton

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Posted 27 March 2012 - 06:09 PM

I believe both HDMI and HDSDI output 60i with excessive frames being flagged properly to get true 24p out in external recorders that can read those flags.

B&H Photo and Video's YouTube channel has a 44-minute video introducing the C300 and this is where I heard this.

Sorry. On mobile, otherwise I would post direct link.
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#3 Kevin Burton

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Posted 27 March 2012 - 06:59 PM

Here's the link. Very informative video.


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#4 Jaron Berman

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Posted 27 March 2012 - 07:52 PM

Yes, it's 60i only but as mentioned it does flag duplicate frames. All recorders I've tried, even the cheap Samurai can properly flag and remove pulldown from the signal.
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#5 Kevin Burton

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Posted 27 March 2012 - 07:59 PM

Yes, it's 60i only but as mentioned it does flag duplicate frames. All recorders I've tried, even the cheap Samurai can properly flag and remove pulldown from the signal.

Good to know. Thanks!
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#6 Jaron Berman

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Posted 28 March 2012 - 05:24 PM

I'd imagine future firmware could add that, doesn't sound like anything too processor intensive for the camera to do, esp. as it has dual digic DV III procs, and adding pulldown should be a lot more difficult than simply passing the signal through. That said, why would anyone in the live world use a switcher in Sony-specific pSf mode is beyond me. Essentially every piece of equipment in the broadcast world is most comfortable at 60i. I'm not doubting that situations exist where people are live-switching in psF but the Sony flavor of pSf is not universally compatible. C300 outputting 24p and F3 outputting 24 psf are both sending the same number of real frames per second, the difference being that psF is on a 48hz interlaced carrier, and the C300 is on a 60hz interlaced carrier. The EX3, F3 C300, essentially ANY 24p capable camera can output a 60i pulldown signal, they were all built to do so for compatibility reasons. pst is also a compatibility mode, though a LOT less compatible than simple 60i with pulldown, as it requires the equipment to scan at a (now) non-native 48hz. Tube tv's have no problem scanning slower than their usual 60hz but digital equipment might, hence the non-universality of Sony's flavor of pSf. Do you remember when "24p" hit the market for HDV and nobody could read anyone else's tape format of HDV - all different frequencies and flavors of 24p didn't play nice.

For max compatibility, shoot ALL the cams as 23.98p over a 60i carrier and even the first generation of live switcher will handle it beautifully. The final signal will work fine for all televisions, and if the set is decent, it'll recognize the pulldown flags and "reverse telecine" in the final TV, showing a true 24p picture - even though the project itself was shot, switched and broadcast on a 60i signal. Psf......I don't believe that a PsF signal can even be legally broadcast in the US, it requires post-conversion (perhaps internal to the switcher) to be a broadcast legal 60i signal....and at that point - why not just shoot ALL the cams at 60i carrier to begin with and integrate your shiny new C300?????

Sounds like some tech director fed them bad info about how psf is more "real" 24p than simple 23.98 over 60i.... again - either way you're shooting 24 fps.
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