Lighting advice - shooting a beam of light into a pool

[Rob Castiglione]

Hi there,

I shooting a scene in which we need to shoot a person swimming through a beam of light in a swimming pool. It is not a very large or deep pool - Maybe 12 feet deep and quite narrow. One side of the pool has a viewing glass and we are shooting someone swimming through the beam of light. What kind of strength fresnel am I going to need? Cheers

 

[Erich Roland]

rob, hard to say. there are a lot of unknowns. How wide a beam, how much ambient light is there to begin with and how much brighter do you want the beam to be relative to the ambient light. how far from the lit area in the pool can the lamp be rigged, and also what color light. Just a WAG that a stand by the edge of the pool will work, and blue light is appropriate and because an HMI will give you the best bang for the buck, probably a 1800w par will do what you need and have a bit of punch to overcome some ambience with some room to spread out via different lens options for beam size, and you can plug it into a 20 amp wall socket.

 

[Rob Castiglione]

Hi Erich,

Much appreciated. All legitimate questions. I was thinking of an HMI as well - maybe a 2.5. Apparently we are going to need just a single beam of light through the pool.

 

[Johnny Friday]

Or you can use an underwater HMI or LED which would put off a better beam within the water....

 

[Florian Stadler]

Cheap & Effective: par can with very narrow globe (Firestarter) will do the trick

 

[Maz Mawlawi]

I would suggest at least a 2.5K HMI.

 

[Jason Comparetto]

We did a shoot similar to what you describe in an aquarium and used a 4k HMI with a Red One MX and it came out just right. But like others have said, there's many factors. F-stop, exposure, sensor, desired brightness/key look, angle of refraction might make a difference too (i'm not sure abou that one)

 

[Steve Marshall]

my gut says go with a 4k PAR

 

[Matthew J]

Look in the towards of the current American Cinematographer for an article about a short film shot in a tank. The DP used two molebeams, and I believe two 4k's to light it. It might give you an idea. In my gut, I'd say a 4-6k HMI would be your best bet cheaply if you are looking for a beam of daylight sun.

 

[ericyoung]

Make sure your electrician/gaffer is fully qualified. Water and electricity is for sure a safety risk.

 

[Adam Eden]

You will need a 6k Hmi with a clear lens on for spot. If you cant afford that then try a 2.5k with a clear spot lens and bounce it off a mirror. The mirror will amplify and enhance the beam.

I drink Heineken by the way...