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RED Epic Converting 50fps framebase to 25fps (PAL)

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Beverley Callow
RED Epic Converting 50fps framebase to 25fps (PAL)
on Oct 31, 2012 at 4:21:44 am

We have footage from RED Epic that was unintentionally shot at a 50 frame rate and a 25 record frame rate in order to get slow motion, which we think was a mistake on the behalf of the DP, a first time RED user. We need to use this footage. RED Cinema X plays back the footage really fast (double speed?) and we've had no luck slowing it down in FCP7 or Premiere CS6. Is there a way to conform the footage to at least be playable at real time speed? We are newbies on RED and know nothing. Please help!


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David Battistella
Re: RED Epic Converting 50fps framebase to 25fps (PAL)
on Nov 5, 2012 at 7:49:54 pm

Your best chance is to try to use Apple compressor with optical flow on to convert the footage.

I see this mistake OVER AND OVER AGAIN because people who call themselves DP's do not understand the fundementals of film style slo motion (same as RED)

I have a complete article on this here on the cow. About once a month people completely blow a shoot because they think they are using a DSLR, when using a RED.


David

______________________________
The shortest answer is doing.
Lord Herbert
http://www.davidbattistella.com



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Beverley Callow
Re: RED Epic Converting 50fps framebase to 25fps (PAL)
on Nov 6, 2012 at 3:40:44 am

Thanks David,

Yes I can see how it would be a typical error.

Thanks very much for your reply. Could you please and me the link or title of the article. I'll pass this information across to the editor.

Kind regards, Beverley


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David Battistella
Re: RED Epic Converting 50fps framebase to 25fps (PAL)
on Nov 6, 2012 at 5:21:56 pm

Absolutely,

Here is the link to the article.

David

http://library.creativecow.net/battistella_david/Film-Style-Slow-Motion/1

______________________________
The shortest answer is doing.
Lord Herbert
http://www.davidbattistella.com



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Beverley Callow
Re: RED Epic Converting 50fps framebase to 25fps (PAL)
on Nov 8, 2012 at 2:09:28 am

Hi David,

Thanks for the link to the article. As informative as it is in re-examining information found in the manual, there is still little in terms of a solution found on the forum - except maybe your recommendation of compressor. Granted our DOP got the settings wrong and the blood on his hands was due to unfamiliarity with the RED menu system rather than lack of knowledge of traditional slowmo methods. The fundamental problem is the distinction between RED time base and frames per second - again info found in the manual - but in this case the time base was set to 50 and the fps to 25, when to achieve slowmo the setting should have been the other way around.

In order to fix this (we feel it's important to post the results here for everyone) we realised 25fps was still actually captured, yet it always plays back at 50fps, hence playing at double speed. We exported an image sequence - jpeg 1080 - and then went into QuickTime pro 7 and created an image sequence at 25fps (file menu) and exported ProRes proxys. An sure enough we have playback in real time. We'll do the same for the 4k version (yet to be tested) and re-write the timecode in FCP, to match the hi-res version when we confirm in online. All sound was recorded externally and should sync ok.

Although parts of this are yet to be tested it appears to be a solution that is relatively painless. Hope it helps.

Kind regards,
Beverley and Stu


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David Battistella
Re: RED Epic Converting 50fps framebase to 25fps (PAL)
on Nov 8, 2012 at 2:50:07 pm

Beverly,

Thanks for following up.

I had not initially thought of the fact that 25FPS were captured and thus changing the TIMEBASE (set incorrectly to 50FPS) in post would at least yield an acceptable real time image stream.

You could possibly use After effects for this job as well and ask after effects to interpret the footage at a different TIME BASE (24, 23.98, 25) and that could be one alternative way to get the frames out in real time.

Once that has occurred you could slow the footage down by interpolation but 1/2 speed would literally just doubel every frame, not capture the true slow motion at 50 frames per second as the camera can do.

A quick rule of thumb is this:

FRAME RATE (frames per second) is a TOP level menu action, that can be changed right in a top menu on the RED touch screen)

TIME BASE (the system clock for the camera) is located deeper within the menu structure (for good reason to try to avoid these kinds of problems)

So if you find yourself beyond the top level menus then more fundamental changes are being made to the way the camera operates.

I hope that you get the images out this time and that next time there is less confusion.

David

______________________________
The shortest answer is doing.
Lord Herbert
http://www.davidbattistella.com



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Alex Elkins
Re: RED Epic Converting 50fps framebase to 25fps (PAL)
on Nov 21, 2012 at 12:48:10 pm

Hi Beverly,

If I understand you correctly, you have 25 actual frames each second, but RedCine-X and QuickTime play them back at double-speed. If this is the case then it's quite a quick and easy fix using Cinema Tools. No need for lengthy renders from Compressor or After Effects.

To test the theory, render out one clip from RedCine-X as ProRes 422 and place the clip in a folder on its own in Finder. If you play this clip in QuickTime and press CMD+I it should tell you that the clip is playing at 50fps, which is double what you want it to play at.

Right? OK, so here's what you do to fix it:

  • Open Cinema Tools - it will prompt you to save the project before you start working, but it doesn't actually matter what settings you select.
  • Go to File > Batch Conform
  • Point Cinema Tools to the ProRes clip then select Conform to 25.0 fps and hit Conform


This will be an almost instant process. What's happening is Cinema Tools is changing the metadata in the QuickTime file to say it should play back at 25fps rather than 50fps. The clip itself remains unchanged, so there is no quality loss from re-rendering.

You'll find the conformed clip inside a new folder called 'Conformed 25.0' where your QuickTime clip used to be. Open it up and see if it plays back properly.

Hopefully that will get you up and running, but apologies if I've misunderstood the problem.


All the best

Alex Elkins
Twitter: @postbluetv
http://www.postblue.tv
Post Blue showreel
Latest work: Greyhounds in Motion at 500fps
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