Shooting Heat wave/ Mirage

[Dustan Lewis McBain]

Part of the script entails the concept of a madness, that lies within the jungle. Within context, the jungle appears extremely hot. What I'm trying to achieve is to film the jungle from the outside looking in, and I'm hoping to have a mirage, or a refractive heat wave, bouncing from off the ground up. Attached photo is basically what i mean. Does anyone have experience in filming this type of image? I get the basic concepts of a mirage, but I want to be sure of how to go about capturing this before I get to set. Thanks,

[Josh Gladstone]

Well first, it has to be hot enough that you actually see the distortion. If not you're going to have to accomplish the effect in post.

 

But anyway, if you're looking to photograph it for real and not do it in post, the longer the focal length of the lens, the more pronounced is the atmospheric distortion. So get the most telephoto lens you can find, or if you're using a zoom, zoom in all the way.

Edited February 2, 2015 by Josh Gladstone

[Josh Gladstone]

Just for reference, the famous desert shot in Lawrence of Arabia with all the atmospheric distortion was shot using a 482mm lens. I believe the lens was made special for that one shot, and is still available for rent at Panavision, although it's never been used on a single shot in a single movie since.

 

[James Compton]

There's a cheap way to get that shot done. Compose the shot with a lens that is 75mm or longer.

Place a butane powered camping stove about three feet away from the lens just below camera level.

Turn on the camping stove and adjust the heat/flame until you get the level of distortion that you want.

Voila.

[David Mullen ASC]

I've also used a small row of Sterno cans under the telephoto lens. The effect is more wavy, not as ripply as a true heat wave, but it works OK. There are probably better post vex tools now for that effect but I haven't used them yet.

 

But you need to shoot the scene on long lenses in order to make the effect make sense, you wouldn't get a heat wave effect on a wide angle lens.

[Dustan Lewis McBain]

Wow. that lens! Only thing is i can't find a place that will let me rent it :/ .

 

I think definitely using stern cans or some form of fire fumes in front of the lens. great idea. My only worry at that point is losing depth. In the sense that fumes would cover the entire lens, leaving all foreground middle ground and background together fumigated. Same as in the picture i provided I was looking to have the foreground in focus with the characters there. Perhaps using a more directional flame and point it at the middle of the lens, in a horizontal fashion? In any case I would probably just grab an extremely long sense and push back a bit. Graphics I need to look into as well. Interesting thoughts!

 

I'll do more research and If i find anything report back!

 

Thanks guys!!

[cole t parzenn]

But you need to shoot the scene on long lenses in order to make the effect make sense, you wouldn't get a heat wave effect on a wide angle lens.

 

How wide is too wide? If I'm visualizing it correctly, a long lens emphasizes the distortion and a short one deemphasizes it but the distortion is always there. Also, since heat distortion is partly a consequence of depth, wouldn't an extremely long lens deemphasize the distortion, as well?

[David Mullen ASC]

The heat wave is always in the distance -- in real life you need to use a long lens to see it, on a wide-angle lens, it is too small and far away. Can you find a wide-angle shot of a heat wave effect anywhere?

[Dennis Couzin]

Topic is adrift. Heat waves can be produced by camp stoves but mirages can't. Both phenomena are results of heated air having reduced refractive index, but they are geometrically too different to lump together. I suggest cinematographers read the still-amazing 1937 book "The Nature of Light and Color in the Open Air" by M. Minnaert, both for understanding such phenomena and for enhancing perceptions.