23 Nov 2009

Shooting in Slow Motion – Overcranking the HVX

Filming, Post Production 1 Comment

I love the Panasonic HVX200. I love it’s tapeless counterpart, the HPX170 even more. One of the things I enjoy so much about these cameras (considering their price range) is the ability they have to operate in “film cam” mode and shoot at variable frame rates. When you ‘overcrank’ at 60 frames per second and play back the footage, it will be slow motion and have a larger than life feel. Overcranking is an old term that lives on from the days of hand-cranked cameras. A camera operator would crank faster than normal, recording more frames (or images) in the same amount of time.

Slow motion can also be achieved in post production by taking footage shot at a normal frame rate (24 or 30) and then duplicating frames to extend the length of the clip. However, the difference between the two techniques is vastly different. In overcranking, you actually have more images to work with. For example, if you wanted to show the action happening at half the speed of the original clip, you could shoot in 24 frames per second and in your fancy schmancy editing program, slow the clip to 50% speed. This would turn a 15 second clip into a 30 second clip and show each frame twice. The result would be slow, but it would stutter along, not moving for 2 frames and then jumping forward. The alternative would be to overcrank and record in 48 frames per second and show it in a 24 frame per second sequence. This would produce beautifully smooth slow motion, with no duplicated frames.

Now, your assignment: Think about all the beautiful scenes in your favorite movies that have that a scene with a huge, cinematic, larger-than-ilfe feel. Go watch them again and pick out the slowmo parts. Then, slowly let it sink in that you’ve been watching “overcranked” footage since you were in diapers.

One Response to “Shooting in Slow Motion – Overcranking the HVX”

  1. Mark Slater says:

    Always good to learn something new you knew but didn’t know you knew you knew.

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