Lighting through Frosted windows

[Suzanne Smith]

I have an upcoming shoot where I want to cast some light through a window to crate a shaft to look like it's coming from a street lamp outside. The windows are quite small (about 5ft tall, 6ft wide) and are frosted with a texture to them. I'm worried about how well the light will travel through them as I don't want it to just distort and glow, I'm after more of a shaft to give us some background and bring the night light into the room.

 

I'm planning on using a 1.2 HMI and rigging it high outside with some atmos in the room, does anyone have experience with this and know if the frost might create problems?

 

Thanks in advance!

 

 

[Robin R Probyn]

Can you do a check at all..? others have alot more experience than I do with larger lights.. but one universal thing is that the frost and texture on the glass will act as a diffuser ..if its a very heavy frost more diffuse the light.. which can be helpful.. but I would think will make it harder to achieve a shaft effect.. as the light will be scattered about by the frost.. but it will help to "fill" any dark corners the room .. 5' x 6' is a fairly decent size window.. depending how big the room is of course.. !

Edited January 20, 2016 by Robin R Probyn

[David Mullen ASC]

If the window has any kind of frost on it, it will burn out to white when the light hits it. You really need clear glass on the window to get the effect you want.

 

A 5'x6' window is small?

[Suzanne Smith]

Ok thank you, sorry I meant quite big, they're enormous for a pub actually! I don't think the frost is a coating on the glass, it's just glass made with that sort of rippling if that makes any difference?

[David Mullen ASC]

Rippling is better than frost, certainly, but depending on how much rippling there is, it will still catch the light and spread it, but you may still get something of a beam coming through it. I would clean the window as best you can.

[Adrian Sierkowski]

You can always light the window a bit; and then use a head inside the pub to create a shaft, motivated from the window.

[Bill DiPietra]

I don't think the frost is a coating on the glass, it's just glass made with that sort of rippling if that makes any difference?

 

Is it anything like this?...

 

[Mark Kenfield]

With enough haze, you should still be able to get a localised glowing ambiance from frosted windows, but you won't get the kind of focused beam that you would from an undiffused beam into haze.

 

I'd look into Adrian's suggestion and see if you can cheat it with the addition of a hidden fixture inside the window.

[Suzanne Smith]

Thank you all so much for your help! We've got some room separators on order and extra bits so hopefully I can hide something away and create the beam from inside as suggested. I'll also make sure the window is shiny clean as well, thanks!