Breaking large panes of glass

[Andre LeBlanc]

Hi all,

 

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!

[John Sprung]

Do you want ordinary glass or tempered glass?

 

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.

 

 

 

 

 

 

-- J.S.

[Andre LeBlanc]

Definitely tempered glass-- thanks for pointing that out. In terms of thickness, single pane would be better for practical purposes.

 

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 :)

[Paul Bruening]

Safety has to be your number one. There was a story on the radio more than a few months back about a couple in England. They were having a fight in front of a store. The man pushed her through a big pane glass window. She fell through without much harm. A large piece of broken glass dropped down on his extended arm, cutting him severely. He bled out before the ambulance got there.

 

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.

[John Sprung]

Another thought -- find an arm from a department store dummy. Light it right and cut it quick. It can be the hand and arm in closeup for the actual break. The real guy would do the non-destructive hits only.

 

 

 

 

-- J.S.

[Andre LeBlanc]

Yeah, I think there's several good ways to cheat this. Now I'm thinking you wouldn't even have to be looking directly at the window when the first break happens. It could be a cheat. Intercut with plenty of medium and close shots. I definitely want this to play safe!

 

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.

[John Sprung]

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?

 

 

 

 

-- J.S.

[JD Hartman]

Breaking a pane of tempered glass doesn't present much of a hazard, but does produce a large mess. Be prepared a lengthly cleanup and the possibility that the sequence might have to filmed more than once. In a sequence we filmed, one character picks up a a 2x2' glass table top to separate himself from his angry father. He then drops it, shattering the glass. We had a disposable carpet in the room to catch most of the fragments, but it took some time to find and vacuum up all the bits that had scattered throughout the room.

Glass dealers might be able to provide you with identical pieces or tempered glass removed from store windows or displays.

[Freya Black]

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?

 

-- J.S.

 

 

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.

 

love

 

Freya

[Freya Black]

Okay I'm not making it up.

 

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:

 

http://www.breakawayfx.com/

 

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.

 

 

love

 

Freya

Edited March 11, 2010 by Freya Black

[Brian Drysdale]

I saw an extremely drunk man bouncing several against a large store window without breaking it.

 

I'd use the breakaway glass, tempered glass doesn't really break the same way as plate glass.

[Freya Black]

Got talking to some people about this.

 

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.

 

love

 

Freya

[Andre LeBlanc]

Hi all,

 

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

http://www.alfonsosbreakawayglass.com

 

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.

[James West]

Not sure if I'm stating the obvious, but 2 things I would consider for broken glass flying towards the camera: backlight and slow motion