Over / Under Crank ?

[zone6]

Can someone please tell me how to go from slow motion to fast motion or vise versa during the shoot without having to stop the camera?

I am a new user and am confused about how shutter speeds and frame rates differ. It's the frame rate capture & playback that determines the look of the clips right? Shutter speed as I understand it works with aperture or iris to control exposure, not speed, right?

Thanks!

[THoff]

You can't chance framerates in the middle of a recording. You can change shutter speeds, however. You'll have to handle speed changes in post.

The aperture is purely optical (except when gain is added), but the shutter speed / shutter angle are electronic.

Probably the easiest thing to do for adjusting recording parameters mid-shoot is to create scene files with the desired settings in adjacent positions -- you can then change from one scene file to another using the dial.

[David Saraceno]

Probably the easiest thing to do for adjusting recording parameters mid-shoot is to create scene files with the desired settings in adjacent positions -- you can then change from one scene file to another using the dial.


Could you explain this further.

Shooting a touchdown run, and knowing the guy is going to score, what is done to in mid shoot changes so that last ten yards are slow mo when I start at 720/24pn

[Barry_Green]

To do it properly, you wouldn't start out in 24pN. You'd shoot the whole thing at 48fps and play back at double-speed (so 48fps plays back every other frame in a 24fps timeline, delivering normal motion) and then for the slow bit you'd let it run at the normal 48fps-in-24fps speed.

Slowing down 24fps footage in post is going to look awful. You need to have captured it at the faster frame rate in the first place for quality slow-mo.

[THoff]

The frame rate and recording format are about the only thing you cannot change mid-shoot, scene file or not. Other things like the shutter speed can be controlled this way.

You can change the scene file while you are recording, and the shutter setting etc. takes effect immediately as you change the dial position.

Edit: Regarding speed changes in post, Edius for instance has a pretty powerful time remapping function that can be used to speed up and slow down video in post with very good quality.

[dregenthal]

Shoot the whole thing at 720/24p 60 and, as THoff said, handle it in post.
This way you can contcenrate on getting the best shot.

"curses, foiled again!"
(you guys all type much faster than me).

[zone6]

According to Apple, "its possible to change the frame rate during filming, creating speed changes (from slow motion to fast motion) during a single shot".

How do I do this with the HVX200?

[zone6]

Barry - how do I set the playback at double speed? Does the speed you refer to have anything to do with shutter speed?

Sorry if this is a lame question / thread. I can't seem to get the difference between shutter and frame rate. I am new to video. I understand shutter speed and aperture as it relates to photography as I work with old view cameras and sheet film everyday. With still photography, I can control the "look" of speed via the shutter of my lens. With video, fps, frame rates, shutter speeds, record, playback .... AAAAHHHHHHH :furious3:

I'll get it here sooner or later.

Thanks!

[David Saraceno]

While this affect is a little overused, it still is interesting.

Wondering if someone has done this might detail the exact workflow, particularly for Final Cut Pro.

I for one would appreciate it.

[Barry_Green]

Barry - how do I set the playback at double speed? Does the speed you refer to have anything to do with shutter speed?
Nothing to do with shutter speed. But you'd set that playback speed in FCP, and I don't know FCP. In Vegas you'd just right-click on the clip and tell it "playback speed: 200%" and it'd play back twice as fast, which means that you'd get 24fps from your 48fps footage. Then for the part you want to cut into slow-mo you'd cut the clip and set that portion of the new clip to play back at 100% speed.

I'm sure FCP can do similarly, but some FCP expert would have to answer as to the proper steps.

[BenB]

FCP, two options:
1- constant speed change, right click, go to Speed, fill in the blanks.
2- variable speed change, use either the Time Remap tool in the Timeline, or the graph in the Viewer's Motion tab.

Ok, as per your email, Apple's doc does in fact say you can change frame rate during a shoot. But this is becaue there are cameras that can do this. They did not say every camera made could do this. Just that it was one technique possible to achive that effect.

Unfortunatly, the DVX and HVX can't do this. I wish I had enough money to buy a camera that did.

[zone6]

Just watched "The Longest Yard". In the football scenes, they went from slow to normal to fast and slow motion again, all in the same shot. Is this only doable with a camera like the Viper? If its possilbe to achive a similar affect with the HVX can someone please let me know?

Thanks!

[BenB]

No, can NOT be done "in camera" with the DVX or HVX. Can be done in post with FCP or other major NLE. Period.

[zone6]

Hi Ben -

I thought you said doing it in FCP looked bad somehow. Just curious if you or anyone has seen the movie with the scenes I'm talking about. If, so, is that the Viper camera you told me about?

Thanks!

[BenB]

I don't think I said it looked "bad" in any NLE, just not clear like it is when shot in-camera. But, you're only option is FCP's Time Remap Tool. Once you wrap your brain around the tool, it's not hard to use, with patience.

I've never used a Viper, but I would assume that digital film cameras like that can do speed ramps in camera. At least that's what I hear. But, I don't own one...

[kwoff]

A lot of people seem to feel that Shake provides better results for changing frame rates than FCP, and, to my eye, the Time Warp filter in After Effects 7 also provides better results. I don't know if Shake provides speed ramping or not, but AE 7 does. I haven't used either on DVCPro HD footage--I haven't needed to for my purposes since the HVX has variable framerates. There is a free tutorial somewhere on slo-mo in Shake from Mike Mensh, one of the Shake commentators on Creative Cow. (I can't find the link right now.)

[David Saraceno]

http://forums.creativecow.net/cgi-bin/page_wrapper.cgi?forumid=1&page=http://www.creativecow.net/articles/mench_michael/slow_motion/index.html