Overpowering Sodium Vapor Lights

[Jonathan Bryant]

I have a few upcoming shoots in a large factory. Just recently we sold some of our aging lights like Lowell 2k softlights. From the looks of it the factory has mostly Sodium Vapor lighting around 2500-2900k with a couple of blue looking fixtures around 3200k-3600k.

 

Because the final product won't have a ton of factory shots we are on a tight budget, we have tons of 500w-1k open faced lights,650w Arri Fresnels, 1k Soft Boxes, and 2ft 4 bank Kino Flos. But I think we need some bigger fixtures so I am looking at this 2k Altman Soft Lights http://www.bhphotovideo.com/bnh/controller...egoryNavigation. What do you guys think? I would like to light up to a 50ft by 50ft section at most hopefully overpowering the factory's lighting.

 

SHould I rent a HMI and gel it to match? What are the highest wattage 110v fixtures you can get? Would you gel the tungsten lights with a 1/8th CTO? What would you do to get great looking wide shots in a factory that has ugly orange lighting?

[Jonathan Bryant]

I forgot to say that the Sodium Vapor Lighting was reading at about 2.8 on my DSR500. I am not sure what the DSR500 is rated at in terms of ISO maybe someone on here knows.

[Thomas Burns]

Jonathan,

 

What you are trying to shoot? Are you photographing an empty warehouse? Are actors involved? Are these one-off shots, or are you trying to build a scene (master, coverage, etc.)? The answers to these questions are the single most important factors influencing your lighting decisions.

 

If you have control over the native sodium vapor units you could turn them off and start from scratch with your tungsten heads, but why fight it? If you need "great looking wide shots", as you say, then you'll need the light to cover most of the warehouse, which is what the sodium vapors are doing for you already. With the little information I have, I recommend gelling your tungsten units to match the sodium and then white balancing as needed. The blue looking fixtures you mention are most likely mercury halide lamps. If there's only a few of these, I would try and find a way to prevent them from contaminating your set (i.e., turn them off, or flag them off if they're not too high). Or perhaps they provide an interesting addition. What you should aim for here is a level of control over the lighting. There have been lots of posts on this site regarding which gel cocktails will balance tungsten to sodium vapor--a search will give you lots of options. 1/8th CTO on a tungsten head is not a good match for sodium vapor.

 

Unless you're dealing with daylight through windows or skylights, or a preponderance of mercury halide lamps, I don't think an HMI is what you need. It's true that HMIs are much more efficient than tungsten lights when it comes to footcandles per watt, but after you correct them back to your warmer color temp it's almost a wash anyway. The presence of windows or skylights presents an entirely different scenario, as you would then consider moving over to a daylight lighting platform.

 

110v lights come in all shapes and sizes. Most 10Ks run on 110v power, but that doesn't mean you can use them on the factory's house power. The name of the game here is amperage, and without a generator you're most likely stuck using 20 amp edison circuits. Generally speaking, a 2K is about all you can put on a circuit and feel safe. In a pinch you could run a 2K and a very small unit (a 2K draws 16.6 amps), but I don't recommend it.

 

This is a great lighting exercise, and it won't be the last time you encounter this kind of set-up. Enjoy it, and let us know how it turns out.

 

Thomas Burns

Electrician/Novice DP

Los Angles, CA

[Jonathan Bryant]

I figured 2k was the max I could go. I will be shooting a assembly line of people molding large shiny metal objects. That is why I figured the soft lights would be better than fresnels.

 

The Altman 2k soft lights seem like the most economical way to light large areas. Do you think two of those would do the trick? Then add some large white boards? Any suggestions on large 110v fixtures would be greatly appreciated.

[J. Lamar King IMPOSTOR]

In a situation like this I prefer to not use the Sodium Vapor lights at all, even mixed with tugsten fresnels gelled to match. I've run into a problem especially on video where the Sodium Vapor lights leave a nasty looking redish tint in the skin tones. In one case, damn near impossible to time out. What's worse is I couldn't see it on set with the naked eye. So I'd rather be safe than sorry when I want a normal white light look. I would turn off the Sodium Vapor lights completely and light with my tungsten units.

 

If you have a lot of 1K open face lights you could group them up and bounce them out of an 8x Griff for a large soft source. 650 fresnels can be thrown 30 to 50 feet and make a nice subtle back/edge light down on the end of the beam.

Edited December 13, 2006 by J. Lamar King

[Jonathan Bryant]

I was thinking about shooting multiple 1k Dp lights through a 2 by 4ft Diffusion frame. How many do you think I would need to light a 50ft by 50ft area? I think I would lose some candles if I bounced it though its a good idea for a smaller area. I hope to turn of the Sodium Vapors if I can but they may not be on enough seperate circuits to turn them off and not effect other parts of the factory. Even if I turn off the closest Sodium Vapors should I still use a CTO on my lights to match if I have some spill from nearby lights?

[Alex Haspel]

I forgot to say that the Sodium Vapor Lighting was reading at about 2.8 on my DSR500. I am not sure what the DSR500 is rated at in terms of ISO maybe someone on here knows.

 

the dsr 500 is pretty sensitive, something around 2000lux at T11, wich equals about 800asa