Magic Lantern Forum

Using Magic Lantern => Tutorials and Creative Uses => Topic started by: Dolenc on November 21, 2012, 10:31:59 AM

Title: Slow motion.
Post by: Dolenc on November 21, 2012, 10:31:59 AM
Hello ML users!
First of all I'd like to say thanks to creators of ML for 600D EOS it is fantstic.

I have one question though.
I can't find any good tutorial for how to create a good slow motion video with MLs FPS override function.

Can you help me with this?

Thank you very much!

Hope to hear from you soon!

Bye!
Title: Re: Slow motion.
Post by: nanomad on November 21, 2012, 10:51:56 AM
Sadly, you can't do real slow-mo with FPS override.
Title: Re: Slow motion.
Post by: Dolenc on November 21, 2012, 10:58:25 AM
Thank's nanomad.

So I understood it correctly that FPS override is used just for FPS under cameras own fps...

But there is a way of recording a video of at least 37 fps which is quite good for me. I just need a film look slow motion. Not something extreme.

Is there some other way? Other than Twixtor obviously. :)
Title: Re: Slow motion.
Post by: cartola on November 21, 2012, 11:44:23 AM
Hi Dolec,

as far as I know you can make any video "look" like slow motion using any video editor capable of changing the speed of the video, like kdenlive, adobe premiere and probably many other. The thing is that usually when you do this you make the film with a bigger fps rate, so that when you reduce the speed you can still have something resonable, like 24 to 30fps showing the slow motion. The top fps that your equipment is capable to make depends on its hardware, so ML can't increase the fps. You can still make the normal movie and make a slow motion in an external editor, but as long as you will have less frames it can look really bad, depending on how much you change the speed.

I guess that usually people use the fps override of ML to reduce the fps rate, so it is the opposite of what you want, allowing, for example, longer frame expositions.

Cheers, Cartola.
Title: Re: Slow motion.
Post by: Malcolm Debono on November 21, 2012, 02:12:03 PM
Best method for slow-motion:
- Set camera to NTSC
- Shoot at 720p60
- Use a high shutter speed *
- Interpret footage at 24 fps (or your output fps)
- Use Twixtor to further slow down footage

* Using a high shutter speed reduces motion blur between shots, thus makes it easier for Twixtor to create in-between frames
Title: Re: Slow motion.
Post by: ilguercio on November 21, 2012, 03:43:37 PM
Quote from: Dolenc on November 21, 2012, 10:58:25 AM
Thank's nanomad.

So I understood it correctly that FPS override is used just for FPS under cameras own fps...

But there is a way of recording a video of at least 37 fps which is quite good for me. I just need a film look slow motion. Not something extreme.

Is there some other way? Other than Twixtor obviously. :)
Why 37 fps?
Anyway, sure, if you set the camera to 720p at 60fps (or 50fps) you should be able to crank the fps down to your desired value.
Provided that your camera can do 720/60-50.
Title: Re: Slow motion.
Post by: Malcolm Debono on November 21, 2012, 04:33:06 PM
Quote from: ilguercio on November 21, 2012, 03:43:37 PM
Why 37 fps?

To my knowledge that's the max fps that can be achieved through ML's custom frame rate at 1080p.
Title: Re: Slow motion.
Post by: ilguercio on November 21, 2012, 04:42:06 PM
Quote from: Malcolm Debono on November 21, 2012, 04:33:06 PM
To my knowledge that's the max fps that can be achieved through ML's custom frame rate at 1080p.
Ah, but since 37 is a prime number i would go for 36 instead :P