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Slow Motion video
Hi, here is how I make the footages to slow motion.
I shoot at 1280×960 50fps on my 5D Mark 3.
The create a sequence of 720p 50fps.
Import the footages to it.
Then whichever file I want to make slow motion, I simply drag it to the timeline, right click, change speed to 50%.Is this the right way or there is any other way to do it ?
And is my sequence settings right as per my recording ?
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7 Replies
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Hi,
You are correct, this is the usual way of applying slow motion. However, you can use something called “overcrank” meaning filming at a faster frame rate and then editing using a lower frame rate, thus taking advantage of the additional frames in the source clip. The term “Overcrank” is from the early days of film when the camera was cranked by hand and the operator would crank faster when they wanted the playback result to be slow motion.
If you shoot a 10-second clip at 50fps, then play that footage back at just 25fps, it would take 20-seconds to play and would play very smoothly since no frame is repeated, unlike slowing a 25fps source clip by 50% which simply plays each frame twice, creating jerky motion.
Premiere is intelligent and when you place a 50p clip into a 25p sequence, it assumes that you want the 10-second clip to remain a 10-second clip, so it just plays every other frame to simulate a 25p clip and it looks fine. However, if you change to 50% speed, it then uses ALL of the original 50p frames to provide very smooth playback. It does not need to duplicate frames – they already exist, and it uses them. Of course, if you drop to less than 50% speed, then some duplication will occur and the motion will no longer be silky smooth.
For folks shooting 60p, same thing applies when editing at 30p and using 50% slow, however you would also have the option of editing at 24p and using 40% slow to achieve even slower smooth motion.
Some older Premiere versions (sorry, don’t know when the change happened) might require you to right-click the clip in the Bin and select “Modify > Interpret” and then manually change the frame rate from 50 to 25 for instance. Then the clip will play at 50% without applying slow motion effect. You could still use Interpret with the new version if you wanted, but I’m told that leaving that setting alone and applying 50% slow, Premiere will automatically use the extra frames available to it.
I have limited experience with this effect as my own video cameras shoot at 1080i only. However, I did recently get a little GoPro camera that offers 720p60 shooting. I placed that footage into a 30p sequence and was able to get beautiful silky-smooth 50% slow motion, unlike the results I’m used to when NOT using “overcrank”.
Thanks
Jeff Pulera
Safe Harbor Computers -
So do you mean, I should keep my sequence settings to 25fps only ?
And lets say, I have 5 footages, all of 50fps and I just want to slow down 2 footages.
So, I simply do right click, speed to 50% and get the silky smooth slow motion?
So, those slow motion footages play at 25fps on a 50fps sequence and the normal footages play at 50fps ?
Is that okay ?
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If you put a 50p clip into a 25p sequence, it will play like it is 25p footage. You don’t have to do anything, Premiere adjusts it for you so that a 10-second clip is still a 10-second clip, UNLESS you apply Speed Change.
Blu-ray for instance does not support 50p/60p, so there is no need to edit in one of those sequences. Just edit in a 25p/30p sequence, and take advantage of the slow motion capabilities from the 50p/60p footage then.
Thanks
Jeff Pulera
Safe Harbor Computers -
Okay, so you suggest to keep the sequence settings as 25fps only and simply do 50% speed reduction for slow mo required footages and job done.
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That is correct. 50p/60p are not really accepted broadcast standards, not supported by Blu-ray for instance, so no advantage to editing at 50p/60p, as final export would be 25p/30p anyway in most cases. Take advantage of the slow-mo.
Jeff Pulera
Safe Harbor Computers -
[Jeff Pulera] “50p/60p are not really accepted broadcast standards, not supported by Blu-ray for instance”
Well they are both supported in 720p.
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Tero,
Thank you for adding that, I was thinking in the 1080 domain, but of course you’re correct that one could export at 720p resolution and use the higher frame rates.
Regards,
Jeff Pulera
Safe Harbor Computers
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