240 fps to capture shattered bottles, or glass

[James B]

Hi

Can anyone who has done a lot of slo motion work tell me if 240 fps is fast enough for capturing exploding bottles or glass?

 

Perhaps in conjunction with Twixtor if shot against blu-green screen in a studio??

 

Was thinking of renting the Sony FS700

 

Trying to capture something similar to this

 

http://www.fotosearch.com/ATB425/um121/

[James B]

Also, was hoping someone might know the best way to SAFELY film this type of effect in the studio.

[Benjamin Davis]

Shooting at 240 frames per second will allow you to have a fairly smooth slow motion shot, but capturing every single little piece of glass breaking apart may require a higher speed camera. You could rent a popular high speed camera like a Phantom, but it's daily renting price is pretty expensive. There are probably cheaper alternative cameras that are rentable for much cheaper, but I'm not exactly sure who makes them, and where you could rent them.

 

Using Twixtor to slow down the shot is alright, but Twixtor is prone to distortions and blurring. I believe there are ways to get around that with additional plugins that scan each frame that's been affected and correct it, as well as manual methods of adjusting the affected frames. Otherwise, most editing systems will allow you to adjust the clip's speed fairly easily on the timeline, and you should have no problem with distortions or blurring doing that.

 

You can buy prop bottles and glass specifically made to be smashed over the head of an actor without causing any damage, called breakaway glass or sugar glass. It comes in all shapes and sizes like bottles, windows, vases, vials, etc. It's made by dissolving sugar in water and heating it to a certain degree until it hardens somewhat. Then you let it cool down, and it becomes far stronger, but still very easy to break and safe for stunts. Making it yourself is a project on it's own, and will require a lot of trial and error with molding it into the proper shape, but it may save you quite a bit of money doing it that way. Looking through breakaway prop sites, the average breakaway beer bottle price is $10-$25 each, and a simple lab vial prop is $150.

 

Otherwise, you could use a traditional glass bottle and explode it, but I'd exercise safety precautions and be at a distance while also protecting the camera generously with some sort of plexiglass shield in front of it. The last thing you'd want is to see a pieces of glass lodged into the camera.

 

Good luck!

[David M Aronson]

I've shot a bowl breaking at 240 FPS on a Red Epic. it's slow enough that you can tell it's slow motion, but not slow enough to drag on forever. I'll try to post a link to the footage.

[Benjamin Davis]

I've shot a bowl breaking at 240 FPS on a Red Epic. it's slow enough that you can tell it's slow motion, but not slow enough to drag on forever. I'll try to post a link to the footage.

 

Yeah, I'd guess that 240 fps would probably be slow enough, especially if he's planning on using Twixtor and slowing it down even more by duplicating the frames (1, 1, 2, 2, 3, 3, 4, 4, vs. 1, 2, 3, 4,) and then adjusting the speed to make it a lot slower. If he can effectively remove all of the distortions that come with Twixtor and similar plugins, then I would recommend this to save money for the prop pieces or something.