LEDs, Humans, And The Science Of Light

Posted by Ramzi Abed - in Uncategorized - Comments Off

A View From Behind the Meter


I have used 3200 degree tungsten lighting from my first days lighting stage productions in a Children’s Theater in Miami Florida down to this day. One of the reasons was that when I started, it was practically the only systems available. There were no HMI’s or Kino Flo’s and LED’s weren’t even in the imagination of the lighting engineers who manufactured lighting instruments at the time. I embraced the technology because it was there and it was all that was there. Having spent so many years working with these familiar instruments has made me very prejudice towards anything new and different in the lighting field. I think this is probably a natural phenomenon of the human condition.

I actually encountered Mole-Richardson instruments in 1971 when I first came to Hollywood and those were the regular ten K’s and five K’s with the original tungsten bottle globe. These globes had iron filings in the glass envelope surrounding the filament to clean the build-up of carbon deposits on the inside of the globe. They were large ungainly and exceptionally hot. It would get so hot on the stage that the art directors would complain about the perspiration from the electricians in the rigging dripping onto the freshly painted sets. Since that time I have seen the metamorphosis of these instruments into the streamlined products we work with today but undeniably they are still just as hot. The presence of such heat is one of the drawbacks of this method of lighting.

Besides heat there is the ever-present amperage draw problem. A one thousand watt instrument draws 8.3 amps. That means one can comfortably put only two on a 20 amp circuit. These same tungsten instruments are 85% heat and 15% light. We are really using a refined heating coil to produce photons. I always hear the term warm light when technicians refer to the 3200 based lighting instruments and they are absolutely right. It’s as if we are lighting the room with burning logs. 85% heat is highly inefficient and goes against the direction of the modern green technology that is present in out thinking today. I loved the Mole and Arri tungsten lights for at least a half a century but I have to admit they are becoming dinosaurs in our industry. Just as film cameras were eclipsed by digital cameras so will the tungsten light be eclipsed by the LED technology. It is an inevitable outcome of the conflict.

Here at Birns & Sawyer we are in the process of selling our tungsten instruments and obtaining an inventory that encompasses LED technology. We are selling our Mole Babies, Tweenies, and Baby Juniors and replacing them with LED equivalents. We are selling at exceptionally low prices so as to move them in rapid order. Our tungsten rental inventory is being asked for less and less, especially in the larger wattages, and therefore we are engaged in replacing them with modern systems. We are replacing them not because they can’t do the job required but instead they do it with such gross inefficiency that it is becoming less cost effective. The cost to the producer will eventually become apparent as that awareness becomes common knowledge. Two very hot 1K tungsten lamps can be replaced in a room setup by ten LED lamps in the same 20 amp wall socket with little or no heat build up. To me the handwriting is on the wall and my prejudice, however warranted, must stand aside and make way for the future of lighting. We will be lighting with LED’s in the near future and it behooves me to learn how they differ or how they are the same as what I have been using this last half century.

Michael J. Rogers

Lighting Consultant

Birns & Sawyer

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