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Using Magic Lantern => General Help Q&A => Topic started by: mahmutakay on October 29, 2015, 12:11:13 PM

Title: 50fps slow motion stretching to 1920x1080 / 16:9
Post by: mahmutakay on October 29, 2015, 12:11:13 PM
As we know, when you shoot 50fps for slow motion, the footage comes out 'squashed' and you have to stretch it out to match your resolution - in my case it's 1920x1080 / 16:9.

I've always stretched it out manually to a size that felt right to my intuition, though it's too arbitrary and inevitably comes out inaccurate in it's sizing.

Are there any more specifics for how I should stretch it out to attain an accurate image? I'm using Final Cut Pro.

Cheers.

p.s. I shot on a Canon 5D mark iii
Title: Re: 50fps slow motion stretching to 1920x1080 / 16:9
Post by: Danne on October 29, 2015, 01:33:28 PM
Mlvfs adds a correction "default scale tag" to stretched footage. This corrects the footage to normal automaticlly when opening up dng files in adobe camera raw. Try and see if this also works with dng files in final cut pro.  I also added the default scale tag to my workflow in cr2hdr-r so that works too.
Title: Re: 50fps slow motion stretching to 1920x1080 / 16:9
Post by: mahmutakay on October 29, 2015, 03:04:39 PM
Thanks for the response Danne. I'll give that a g and let you know. Is this for MLV files only? My workflow is to shoot RAW (not with MLV sound rec) then RawMagicLite to convert to DNGs and then DaVinci Lite to Quicktimes.
Title: Re: 50fps slow motion stretching to 1920x1080 / 16:9
Post by: Danne on October 29, 2015, 03:08:33 PM
Cr2hdr-r version 12.2 works also with raw files.
Title: Re: 50fps slow motion stretching to 1920x1080 / 16:9
Post by: mahmutakay on October 29, 2015, 03:30:35 PM
I can't find where to download it, do you have a link? I'm on OS X.
Title: Re: 50fps slow motion stretching to 1920x1080 / 16:9
Post by: rbrune on October 29, 2015, 05:37:49 PM
The correct scaling factor is 5/3 = 1.666[...] as it uses a binning rectangle of 3 by 5 pixels to create one output pixel.
Title: Re: 50fps slow motion stretching to 1920x1080 / 16:9
Post by: DeafEyeJedi on October 29, 2015, 06:03:21 PM
http://www.magiclantern.fm/forum/index.php?topic=13512.0
Title: Re: 50fps slow motion stretching to 1920x1080 / 16:9
Post by: cmccullum on October 30, 2015, 02:59:21 AM
QuoteMlvfs adds a correction "default scale tag" to stretched footage. This corrects the footage to normal automaticlly when opening up dng files in adobe camera raw. Try and see if this also works with dng files in final cut pro.  I also added the default scale tag to my workflow in cr2hdr-r so that works too.

I was losing my mind trying to figure out what was happening because I haven't had to stretch my videos!
Title: Re: 50fps slow motion stretching to 1920x1080 / 16:9
Post by: mahmutakay on October 30, 2015, 01:57:39 PM
So what would the scaling factor on Final Cut Pro be? Is there a specific number I can put in?

Thanks for the download link, I'll have to use that for another project as I've already transcoded these and in the edit, the deadline's real soon for the client.

Also just to add - I tried it out on some old raw files and all I got were cube files in various folders. Watched an installation video though they ended up with DNG files with the same method.