Breaking large panes of glass
Posted 10 March 2010 - 12:06 AM
Anyone have experience where a character breaks a large piece of glass? I'm planning a short film where a character is ramming his fists (or a blunt weapon) against a large window. We're watching the action from the inside, and the character is on the other side of the glass. Over time, this window has to break enough so that the character can climb or walk through the opening.
There's a few givens:
1) We'd cut away from the action several times, so there's a chance to cut back to the breaking at different stages.
2) The window is large. I'd say about 5ft W x 4ft H.
3) The glass is clear.
4) We're always on the inside. The character is on the outside.
I'm concerned about safety, and of course flying bits of glass going everywhere. I guess that some of this could be done with CG, and clever editing and framing will help, but I'm really hoping for some practical methods too.
Anyone have any thoughts or experiences they could share? Thanks!
Posted 10 March 2010 - 01:11 AM
The ordinary stuff is usually thin, in that size usually double strength, about 1/8" thick. It breaks easily, into big sharp dangerous pieces.
Tempered glass would be thicker, at least 1/4", and much harder to break. The trick is that hitting it square on it's tremendously strong, but whack an edge and it almost explodes into thousands of tiny pieces. It's a lot less dangerous than common glass, but still you want to give it a bit of caution. You could have a grip out of frame hit the edge right when the actor hits the glass to make it shatter.
Habitat for Humanity has stores where they sell surplus used and donated stuff, though IIRC they only handle double pane windows. They might have a lead on where to get used single pane windows, which should be plenty cheap since code mostly requires double now. Try wrecking companies, too.
Posted 10 March 2010 - 01:33 AM
The one downside I can see with tempered glass is the whole window shattering at once, rather than a gradual breaking, or poking through. This sounds like a good thing to test thoroughly before shooting
Posted 10 March 2010 - 02:06 AM
Is there any way the character could throw something like a trash can through the pane? With a long lens from inside, no one would catch that he was actually a safe distance away? Then, cut to a medium shot of him climbing through (with the glass on the floor already cleared away for his feet).
That stuff can fly, too. I'd clear crew well out of the way. Bits of that stuff can end up in your hair and cloths when bursting under shock.
Posted 10 March 2010 - 02:21 AM
Posted 10 March 2010 - 02:42 AM
That being said, has anyone had any good experience with sugar glass? I was thinking maybe it would work for some medium, or close shots, but every time I see it used, it has a milky or yellowish tint to it. It also has a very brittle breaking effect-- the opposite of what I'm looking for.
Posted 10 March 2010 - 11:26 AM
Posted 10 March 2010 - 03:01 PM
Glass dealers might be able to provide you with identical pieces or tempered glass removed from store windows or displays.
Posted 11 March 2010 - 07:21 AM
I remember sugar glass from a long time ago. IIRC, it worked mostly for bottles, not flat panes. Mebbe it looked OK in B&W?
I was about to mention sugar glass too. I'm sure I remember reading about it being used for car windows a couple of times more recently, not sure if it can scale up to large panes but if it could then it seems to me that this would be soooooo much safer than using real glass at all.
If you can use it you can cheat the shots too and shoot with a normal pane until the glass breaks where you show a shot with the sugar glass pane shattering instead.
I'd really be very concerned about the safety with real glass.
Posted 11 March 2010 - 07:45 AM
Here is a company (rather unfortunately located in England I'm afraid) that makes every kind of glass thing you could imagine out of sugar glass. Bottles, glasses, even large panes of glass, so they are feasable:
Maybe the colour won't be as exact as real glass but I bet it could be timed to be okay and as I say you only really need it for the breaking shots.
Most important, it is safe. For me that's worth a lot of cinematography hastles to make it work (assuming there are any)
Not sure about the way it shatters being too brittle tho... That might be a prob.
Edited by Freya Black, 11 March 2010 - 07:49 AM.
Posted 11 March 2010 - 12:17 PM
I'd use the breakaway glass, tempered glass doesn't really break the same way as plate glass.
Posted 11 March 2010 - 12:56 PM
The breakaway stuff isn't made from sugar glass but a special kind of plastic resin so may not have the issues you are concerned about.
I'm also hearing about some special stuff called "rubber glass" which is weird stuff made out of a kind of rubber that also breaks.
The breakaway people can also ship overseas so, maybe they can help afterall, but I suspect there will be specialist people stateside too.
Basically it seems like there are a number of safe technologies so you don't have to use glass.
Hope that helps people.
It's strangely got me quite interested in it all.
Posted 11 March 2010 - 05:08 PM
Thanks for the input! There is a Hollywood location that offers similar services forpanes up to 4ft x 8ft. It's also made from plastic resin, and is absolutely clear-- unlike sugar glass
Talking to them, they'll make anything custom, so it's worth looking into. I'd still use the real glass for setting up the situation, but for the actual 'hero' break, something like this might make sense when worried about safety.
Posted 19 March 2010 - 07:47 PM