Kris P Lettus |
12-22-2012 11:04 AM |
There are hundreds of different lights we use but there are only two major types we use..
HMI (Hydrargyrum medium-arc iodide) for daylight scenes, and Tungsten (which is the type of metal the bulb filament is made out of) for night work..
On paper, HMI burns at 5600 degree kelvin (the measurement of color temperature) and Tungsten burns at 3200 K..
On stage 95% of the time, we use Tungsten because, being a bulb with a filament, not a gas like HMI or Florescent, they can all be run back to dimmers that are controlled by a dimmer board, you can set levels and cues... Like a florescent, HMI's take time to warm up, so you can't really do quick cues with them.. They also pulse on camera (your naked eye can't see it) if they shoot at over 40 frames per second, while our generator is set to run at 60 hertz (the speed at which the electricity travels).. Remember when you watched a movie from the 80's and they showed a computer screen and it looked like it was rolling upwards?? That was because they were shooting at a higher frame rate and there was no way to speed up the rate at which the computer monitor was putting out the info.. The same can happen with any gas lamp, the main one being HMI.. The new electronic ballasts (the old ones were magnetic) have an option to switch to 100 herts or "flicker free".. When I did that highspeed 3d nature movie for Nat Geo and IMAX, we had brand new prototype ballasts that allowed us to go to 1000 hertz, so they could shoot at 1000 frames per second with no lighting problems..
The scene where he comes through the hole, the droid made, that whole set was supposed to be underground, which no light sources, besides what was supposed to be sunlight, so we used (6) 18K (18000 watts) LTM Fresnels (the type of lens).. Other than that, most of the stage work was done in tungsten.. If it is a day scene on stage, we use color correcting gel to change the color temp..
My job involves powering the set, setting the lights, and maintenance of all the gear so everything "hums" together with no problems..
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