300 - Speedchanges

[Kim Frank]

I am wondering if anyone knows how they did the Speedchanges in the movie 300. I mean the fightsequences where it goes from normal speed into highspeed and back again. Is it possible to realize this with a red one, or are 125 fps in 2K not enough to get this dynamic. Also I am wondering about the shutter. You would need to shoot high speed what would result in very stuttery Images when speeded up in post. Did they do the speedchanges in 300 in camera or how did they avoid that. How would I be able to avoid that with red. And even if the other cameras categorie has been deleted: would I be better with a genises?
I'm asking because of a shoot next month, that will require extrem speedchanges, so your answers are more than welcome...

 

[Matt W.]

Those sequences were done with multiple 35mm cameras (each with a different focal length lens) on a single rig and running at high speed. The motion blur was adjusted in post and the (purely digital) zooms covered the transitions between different cameras. You can ditch the multi-camera rig if you don't plan to do the crash zooms. Faking motion blur is not that hard in post, but it's easier if you green screen, as they did.

If I were you, I'd just buy the ASC magazine that covers 300 and google the articles on it at cgtalk.com or whatever; I'm sure the specifics are easily available. Shooting on film would be best for this purpose.

 

[Alexis Hanawalt]

You can do basic frame ramping with the RED ONE. You just input the starting fps, the final fps, and the amount of time you want it to take for the change to occur. If you just shoot everything at high speed, it's pretty easy to just extract frames in post to achieve the same effect.

When I asked at Red Day about the future of being able to make this adjustment on the fly I got a typically RED "you will be very impressed with what you can do with this camera."

 

[Kim Frank]

Thanks for your quick answers.
Alexis: if I would do the ramping in camera I would need to manually open up the iris at the same time, right?
Matt: I am afraid shooting High speed sequences on film is far out of budget.
Thanks for the link, I didn't know this forum.

So I would be able to shoot all in Highspeed than extract Images to get back to normal speed and just add motion blur back again in post? Do you by any chance know how to do that in After effects? Would the timewarp effect be a good choice?

And why does it help to shoot greenscreen?

Thanks again!

 

[Matt W.]

Ramping in camera does require opening up the iris to compensate; if you want a dramatic shift like in 300 or if you're going back and forth between speeds an in-camera ramp is probably not the best choice. For an "homage" to that effect with one ramp or something it's probably fine but 24fps to 120fps is about 2 and 1/3 stops, which is substantial and I'm not sure how noticeable the ramp would be at high speed. Probably fine.

I believe this this is one of the popular motion blur plugins; I've never used it but I've heard good things: http://www.revisionfx.com/products/rsmb/

I assume the foundry probably has a good plug in, too, since motion vectors are their thing. I would do the effect with time remapping at the highest shutter possible and then add all the motion blur in post, or use a 1/240 sec shutter and keyframe the motion blur if needed. Try to avoid a busy background (use shallow focus) or, ideally, key everything; "pixel motion" in after effects is pretty good but I've seen it screw things up badly and it takes higher-end software with hand-drawn rotos to make interpolated frames flawless. I've never done this kind of work (only an amateur compositor for the moment) so I can't help you more than that. There may be a much simpler method. Zack Snyder is from an art school and then vfx background so his tricks aren't the easiest to emulate.

 

[Alexander Ibrahim]

I'd shoot at the highest available frame rate, then do the effects in post.

Shake can do some convincing motion blur, and what's built into Nuke isn't bad either.

Regardless of how you do the motion blur, add it at the end of your processing chain- it usually takes a high toll on your processor.

You should vary the shutter angle with the playback framerate. You can tie the shutter angle to the playback rate mathematically in most decent compositing applications.

 

[Tonaci Tran]

http://www.videocopilot.net/tutorial/speed_variation/

I myself can't WAIT to shoot 100fps 5k. This allow some really clean in post digital zoom-pan and scans.

With red's current slo-mo you can get great results doing it all in after effects. The tutorial above is great.

 

[Celestino Gianotti]

I shoot by default at 100fps, in edit I speedup 4 times the clip and I have standard speed at the meantime. Usualy cut and change speed without ramp... but you must known where cut . In videoclip you can play dirt...