Conforming High Frame Rate To Look Like 25fps

[Nalcyon]

I'm working on a project which uses R3D files shot in 25, 50 and 120fps. i have had to speed some of the 120 and 50 clips up so they play in "real-time". These shots look different to those shot in 25fps: the cinematic blur is gone.

Is their any way i can conform the look of the sped up high frame material to look like the 25fps stuff? ideally using AP, but i could use AE or FCP.

 

[jimhare]

What shutter speed did you use on the overcranked stuff? There is a relative mode that keeps the shutter consistent as you move up and down frame rates.

 

[Stefan Scherperel]

The Blur is gone because your relative shutter speed cannot ever be slower than your frame rate.
at 25fps your shutter speed at 180 degrees will be 1/50th sec.
At 50fps your shutter speed at 180 degrees will be 1/100th sec
at 120fps your shutter speed at 180 degrees will be 1/240th sec.
Now you could shoot your highspeed stuff with a 360 degree shutter, making your 50fps expose at 1/50th sec, but that will look off when the footage is slowed down.

So now on to answering your question. The only way to get that motion blur back is to simulate it. After effects does a good job simulating motion blur. Simply speed up your footage to your proper frame rate, and check the box to enable motion blur. You'll want to go into the settings to set the sampling higher than default. The higher the sampling number the better it looks, but the longer it takes to process.
There are also plugins such as those made by the foundary that can work wonders on your footage as well.

 

[Eki Halkka]

After effects does a good job simulating motion blur. Simply speed up your footage to your proper frame rate, and check the box to enable motion blur.

Sorry, that doesn't work. After Effects' motion blur doesn't calculate blur for sped up footage, it only calculates blur for moving layers and masks etc. (or, if it does, i'd really like to know what button to push ,-)

Frame blending in the other hand sort of works, but using it will give 360 degree shutter and ghost images, unless you shot at a pretty high multiple of the target rate (120 fps might work somewhat decently, 50 fps won't).

There actually IS a way to get decent results with plain AE, but it's rather slow and tedious, especially if one has a lot of footage.

The first step would be to slow down the footage even more: to something like 10% of the real time (equivalent to shooting 250 fps), using AE:s high quality fame blending (which actually isn't frame blending at all, but rather a morph that creates new in-between frames).

Second, you'd speed this 250 fps footage back up by 5X to half speed, this time using the lower quality frame blending (which does what the name states). This will average groups of five frames together, creating 50% speed footage with 360 degree motion blur.

Third, you speed the resulting file up by 2X to get real time footage, without any frame blending, simply skipping every 2nd frame - and voilá, the resulting file has a 180 degree motion blur.

You may still get some ghosting on fast movement, but most stuff should be fine - if you see these problems, simply use higher factors on the speed changes to get more intermediate steps in the blur.

...this said, using i.e. Reel Smart Motion Blur plugin is much easier ;-)

 

[Stefan Scherperel]

Eki, you are right, I was thinking frame blending. But there actually is a way to apply motion blur to sped up footage in AE alone. If you type into the effects search, "force motion blur" there is a plugin that allows AE to apply motion blur to anything. You must also check the box for enabeling frame blending (Make sure it is set to pixel motion for best results), and enable it in your viewer to see the effect applied, but it does override the native frame blending in the plugin. You then just set the shutter angle and go. Not sure how it compares to 3rd party effects, but it does a really nice job.