Light rays through windows

Usman Mukhtar · February 15, 2012

ok so i'm an amateur filmmaker from pakistan i need to know how to make light rays coming through windows....i know that you need smoke to create them but the smoke keeps moving....can someone tell me how to get it right....like in this picture at the back the rays coming from the window....

Adrian Sierkowski · February 15, 2012

Yep. You need smoke, or fog, or haze, or dust in the air; some kind of particle which can be lit up by the shaft. The basic idea is to pump in smoke/let it settle/ shoot. Of course you'll loose smoke over-time, so you have to pause and add in again.

Teddy Smith · February 15, 2012

A Reel Efx DF-50 hazer works great for this. You will need a light outside the window. I usually use a Cinepar HMI. If you can't afford or don't have access to a hazer you can burn a small piece of paper in the room. You just want a touch of smoke/hazer. Do it right before you roll then use a flag to spread to quickly spread it around.

Tom Sykes · February 16, 2012

You just want a touch of smoke/hazer. Do it right before you roll then use a flag to spread to quickly spread it around.

Hey Usman,

Not to oppose you Teddy, but in relation to Health and Safety Regs and not to mention respecting the environment that you are filming in, I would definitely advise not to burn anything on an interior locations. I think this is pretty self explanatory.

You can get really cheap event smoke generators for a small price and create the smoke look that you are going for, although these smoke machines are cheaper and relatively harder to settle and make look like a haze, rather than the building is ablaze, it will save you a lot of hassle in the long run if you were to run into any difficulty with 'fire'.

I filmed in a 19th Century Castle last year and we used smoke machines and still set off the alarms, the fire brigade came out at 11.00pm and the owner had trusted us to be more cautious on set, obviously we weren't aware this was going to happen, it was a big room, but regardless it postponed our shooting time considerably so to be on the safe side, avoid REAL smoke unless you are outside, and if you're in a confined space, just make sure that it's ok and outlined in the risk assessment.

You may also want to research into fanning techniques and how to efficiently manipulate how the fog settles, this is a task in its own right.

Good luck.

Ari Davidson · February 17, 2012

This topic really should be stickied no?

First of all that image has perfect results because it was dodged digitally.

I have used many flavors of hazers/foggers, and the DF-50 is the best. Unfortunately this is one of those "get what you pay for" effects. A colleague told me once that oil based haze solutions tend to disperse better, so if you get pigeon-holed into using something cheap at least try to get a good solution. All and all it's a hard trick to master, and no forum can be in the room with you. My advice is get what you can afford before you shoot, and do some tests (and let us know how it turns

In most cases, smoke detectors operate with a photoelectric sensor. It trips when the beam is refracted by smoke or dense vapor, and then activates a switch to power on the alarm. Easy fix. Tape a cup over the smoke detector, and notify your fire department that you're going to be using smoke FX.

Fun fact about smoke in film: In Dune (1984) they burned tires to create giant plumes of black smoke, and had actor run through the dreck.

Cheers.

Brian Drysdale · February 17, 2012

On one commercial I worked on they used smouldering cardboard to lay a smoke FX. Not recommended it really attacks the back of your throat and you end up coughing. I couldn't understanding reasoning because it was a well established production company and they had a reasonable budget. Ironically the ad for checking your smoke alarms once a week.