Source Lighting

[Matt Rosen]

I have an upcoming project in which I want to light a scene from a single practical source that will be seen in the shot. I want to boost the amount of light coming from this source.

 

Would there be any problems with simply putting a higher wattage bulb into the same socket?

[Steve McBride]

I think as long as the voltage is the same, you should be fine as long as it isn't too much over, but I'd wait for one of the pros to answer.

[Matthew Parnell]

Depends on the fitting. Although we all do it from time to time, I would avoid if possible putting a globe with a higher wattage than the lamp and its lampholder itself are rated to.

 

If you must, do not have the lamp switched on for any prolonged periods of time, and if possible switch off between takes and when you dont need it.

Edited December 27, 2008 by Matthew Parnell

[Michael Collier]

I will back up matt. don't overload any point in the circuit. This includes the rating of the socket. If you need to, usually you can have someone replace the socket in the unit. You could go over the UL rating and have someone switch it off between takes, but that complicates the g&e crews responsibility to make sure its off. It also adds worry of fire to everyone who knows your overloading a socket. If you do start a fire, controlled or not, there will be no where to look but the electric department, with the DP as fall boy if he told his key to over-draw the socket (unless he can skillfully throw his crew under the bus, also not a nobel effort).

 

Sometimes in production its a good idea to play the numbers. If a socket can't support the wattage you want, wire in a new socket or think of something different. Unless your rolling several cameras, or a long steadicam shot you should be able to light from off camera.

 

But those to me seem like your options. I have always been one to light from off screen if possible when a practicle is in shot. It keeps the practicle from being to harsh and glaring, but of course thats a stylistic choice best decided based upon the intent of the shot. i have seen some beautiful shots where the practicle lights everything and is completely burned/flared out.

[Adrian Sierkowski]

I totally agree with the above, though I have, too on occasion thrown up a 100W in a 60 W socket for that 1 shot in a doorway, for example, where there is no other way to light it.

If you're talking household bulbs, you can test some CFLs. I have one from home depot which puts out 300W of light will only pulling 64W of power. From what I saw on video it didn't flicker nor have the green spike and was a 2700K bulb; but on film I'd certainly test it to see how it renders. A color meter can help too if you have access to one. And, so long as all your lights are approximately the same "color," you can time it out in post (e.g. using minus green or plus green as needed to make all your lights look "wrong," on the film, and fixing it in the TK)

Another thing-- don't overload your extension cords. I've had one melt onto the plug on my 2K because a new-guy ran it into the wrong gauge cord. While it didn't start a fire-- though it well could have!-- i had to replace the damned thing which really put a fire under my ass on a Sunday morning.

[Hal Smith]

I used a CFL once that did have a green spike but all I had to do was make a small cylinder out of minus-green that slipped over the bulb. I made a round cap for the top. One trick here, use Permacel J-Lar tape for DIY gel gags, gel repairs, etc. It's absolutely clear and rated so by the manufacturer. I don't know how much heat it'll ultimately take but it I've had it in front of hotter than hades ETC Pars without trouble. Theatrical houses usually have it in stock, it's used to build gel strings for scrollers.

[Matt Rosen]

How should I go about checking the rating of the socket?

[Matthew Parnell]

On most lamps they will have a rating tag on them somewhere, whether it be a sticker on the lampholder or engraved on the base of the lamp.

An important thing to note is that both your lamp and lampshade are rated, and a lot of the time the rating of both can differ dramatically(especially if they were purchase seperately). Your lamp might be rated to 250w but your lampshade to 60w, always take the lower number as your max.

Also remember if you are using blackwrap, diffusion or gel on the lamp to manipulate the light, be aware that these items can reduce the ventilation of the unit and its a good idea to keep that in mind when choosing your prac globe.