Slow Motion Shutter Speed Optimal

B

bentramer81

Well-known member
Regarding the shutter speed, in the major motion pictures to get the cleanest slow motion image do they max out the shutter? I read the 1/48 rate was the norm for major motion picture, and I have been using it, but my slow motion shots do blur.

Thanks.
 
Proper slow-motion is acheived by increasing the frame rate while shooting, then playing back the footage at the desired frame rate. This is called overcranking. For example, a major motion picture might film a slow-mo scene at 120 fps and play it back at 24 fps. This would result in the scene playing back at 1/5th of the speed at which it was acted (120fps divided by 24fps equals 5).

You were right, 1/48 shutter is standard for 24p, but that's only for normal-speed scenes. Also, the XH A1 (I'm assuming that's what you have, considering that you are posting in the A1 forum) does not have an overcrank mode, so any workarounds that you may find, and there are plenty, for slow-motion will involve a fast shutter. However, your footage will still be at 24f (if that's what you're shooting), so it won't look as good as real overcranking.

EDIT: In short answer, to get slow-mo with the A1, you'll want a shutter speed that's way faster that 1/48 sec, otherwise, as you noticed, the picture will blur. I'm not sure if there's a magic speed that will give you the best result, but an optimal shutter speed for slowmo won't give you blur at all.
 
Hmmmm???

Hmmmm???

Aroon_Narayanan said:
Proper slow-motion is acheived by increasing the frame rate while shooting, then playing back the footage at the desired frame rate. This is called overcranking. For example, a major motion picture might film a slow-mo scene at 120 fps and play it back at 24 fps. This would result in the scene playing back at 1/5th of the speed at which it was acted (120fps divided by 24fps equals 5).

You were right, 1/48 shutter is standard for 24p, but that's only for normal-speed scenes. Also, the XH A1 (I'm assuming that's what you have, considering that you are posting in the A1 forum) does not have an overcrank mode, so any workarounds that you may find, and there are plenty, for slow-motion will involve a fast shutter. However, your footage will still be at 24f (if that's what you're shooting), so it won't look as good as real overcranking.

EDIT: In short answer, to get slow-mo with the A1, you'll want a shutter speed that's way faster that 1/48 sec, otherwise, as you noticed, the picture will blur. I'm not sure if there's a magic speed that will give you the best result, but an optimal shutter speed for slowmo won't give you blur at all.
Click to expand...


To up the frame rate for a slo-mo scene to 60 frames wouldn't work in 24f Sequence in Final Cut Pro, right? Does anyone know, can you mix and match 60f with 24f?
 
If you shoot the A1 in 60i (which you should do for slow motion) the optimal shutter speed for smooth slow motion is 1/120. You can also crank that up as high as you want but you will not get as smooth a motion as 60i/120 but instead you will start to experience a different kind of judder to the image.

Once you get your 60i footage...what I do is convert that to 60p (60fps) intermediate clip. Bring that clip into your 24p time line and add to your other 24p footage. Slow it down and render everything as 24p. I use Vegas but it can be done in other NLE's.
 
This might be a bad question but here it goes, how do you convert 60i footage to 60p? Do i add a de-interlace effect to the clip?
 
when you bring your fresh 60i clip into your NLE, set your project preferences for a 60p timeline, apply deinterlace, and render out. you clip will then be 60p. after you do that, then set up a new 24p project and bring your new 60p clip in and slow it down.
 
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