Lighting Units For Miniature Sets
When the camera speed is low and exposure time long, only low levels of light are needed even for 100 ASA film and F-22. (Reciprocity failure lowers Kodak 5248 ASA to about 50 ASA at 1/2 sec. exposure). We sometimes used 5279. Unfortunately existing motion picture and video lights are large even though many accept lower wattage globes. The lower wattage globes that fit in most studio lights have longer life but lower color temperatures. Here are a few solutions to make them useful for your job. If the desired effect is a warm look, the lower wattage globe at line voltage (110-120 volts) and 2800 K might be OK. For an even warmer look yet such as fire or candlelight the globe can be operated at an even lower voltage. Some quartz light globes when run at reduced voltage can blacken and fail early if the lamp glass if not heated to a high enough temperature (275 degrees) to redeposit the evaporated tungsten back on the filament. (See Constant Voltage Control.)
Remember that Freznel type units deliver about 1/2 as much total light as an open face or sealed beam light. 1/2 of the light of the globe in a Freznel light is wasted into the sides of the light housing as heat. There is a compromise between light control and efficiency. More control, less efficiency. Open face units have some light wasted off to the sides of the beam that is often cut off with barn doors. Intensifiers, shiny reflector in front of the light, reduce the amount of lost spill light. Research with shiny barn doors might be worth the effort to selectively increase the output of open face and sealed beam units. For example you might achieve more punch to a distant part of a set. Consider the design of the CYC lights.
We had some Mole Richardson Midgets and Inkies. (200 watt-FEV) They seem to have become more popular with faster films and are not cheap used. They also walk off sets to become artzy home lighting fixtures. We used them because of their great control, pattern and hard shadows. We used some 100-watt, 2800K (ESR) globes which lasted longer. Globes are difficult to change in these lights. Push down hard and twist. Practice with a used or burned out globe. It may help to push the socket interior down a few times first. Push straight down on the globe when changing. Try two hands with the socket in the forward (flood) position. UNPLUG THE POWER CORD BEFORE CHANGING ANY LIGHT GLOBE! Make sure you use a clean paper towel to touch the globe. Wash your hands too just in case you touch the globe. Wipe the globe with alcohol if you touch it accidentally.
We had some 600-watt open face Italian "Red Heads" with polished reflectors and peanut globes. We used them a lot to light larger set. They gave nice hard shadows at a distance to simulate sunlight. Their pattern was very consistent at every focus position. The doors worked quite well. Near the end of the shoot we attached little 12-volt computer cooling fans to each head and the bulb life increased substantially. Fans can help bulb, socket and wiring life when units that are left on for hours. We were not shooting sound, but some fans are very quiet. They don't have to be very big.
Colortran back lights. 650 watt (FAD) / 420 watt (FFM) (3-1/8" long globes). I had a bunch of these and have used them for years, as lightweight location lights. The globe life is pretty good and they will take hardware store 150 and 300-watt lights. The barn doors work pretty well. (Note that hardware store light globes of different manufacture often have different light outputs.)
Bardwell and Mole CYC lights. These take 1000 watt (FCM) and 500 watt (FDF) 3200 K globes (4-11/16" long) and many other 150 to 500 watt 2800K hardware store globes. We often boosted the voltage of the hardware store globes to raise their color temperature and output. The 2800 K lights lasted much longer than the much more expensive 3200K-studio globes. CYC lights are designed with parabolic reflectors so that the pattern has a different intensity with different angles to the fixture. Where the reflector is farther from the globe less intensity is reflected. They are designed primarily to light backings (CYCs) from above or from the floor. You can maintain a more consistent exposure across a flat set if they are positioned high above the set from the side. Place the globe in the horizontal position. The long filament globes are NOT designed to burn vertical.
We used a couple of Colortran "booster boxes" to raise the color temperature and light output. These are 50 lb. autotransformers designed in the 1960's to raise the color temperature and output of household and commercial lighting globes up to 3200 K or higher. They can increase the output of Par 64 type lights to about 2-K. Finding some of these would be a solution for many lighting problems such as line loss and adjusting voltage up or down. (You can select higher voltage inputs to lower output voltage.) Another solution is Variacs, which are quite expensive. Another solution is multi-tap autotransformers and isolation transformers with multiple taps. (SurplusCenter.com).
Tan colored Smith Victor Focusing 600-watt light with Peanut globes. These units gave hard shadows and a spotty center pattern that was helpful for lighting a set all the way across with the same intensity directing the spot pattern on the farther parts of the set and spill on closer parts. Some study with mirrored barn doors might make these even more efficient. Unfortunately there are many different types of globes for each different brand of lights.
Dedolights. Great little but expensive lights. They have 50 and 100-watt globes but put out a lot of light for the wattage. They run with a higher color temperature than most 3200 K lights in housings with Freznels but the output and color temperature is adjustable. They give hard shadows, can be used up close and are very controllable.
Hardware store work lights. Cheap and have poor patterns, but are great for work lights, soft boxes, and bounce light. You can use one to save your key light when lighting if you place it close to your key. Set decorators and builders CAN use them too as work lights. (You will have to be diplomatic to get people to NOT use movie lights for drying paint and work illumination.) We removed the safety glass for cooling and use the safety glass frame for holding black wrap or attaching barn doors. You will need to make 5/8" sockets to attach them to baby stands or other stands. If used in a soft box you can attach the supplied floor bracket on top of the bottom of the soft box and put a socket to attach the box to the stand on the bottom of the box.
We made 24" x 24" by 24" deep Soft Boxes out of foam core. They didn't hold up as well as they would have with a thin plywood bottom. The Rolux diffusion on the front kept the shape square.
Colortran and Japanese Broads with 4-11/16"long globes. Good for uses above that need a consistent pattern. They do not focus. They do not give shadows as hard as the peanut globes because of the longer globes unless used at a distance.
R-20, R-30- and R-40 mushroom globes. About 2800 K or lower. Soft, cheap, smooth pattern. The original Ross Lowell Kit had great little barn doors for the R-40 globes. I still have some. His sockets were also great. Don't know if he makes them any more. These got him started in the lighting business.
12-Volt Lights Halogen T-3 Bi Pin 5 to 35 watt bare globes. Start with www.allelectronics.com
These are real winners for small sets. They can be found for as little as $10. as desk lamps with globes, sockets, transformers, bases and support arms. The bases and transformer can be detached and placed separately. The reflectors are quite efficient and the pattern quite good. We removed the safety glass, but that is your option and not recommended by us. We have put them in white plastic 4" sewer pipe and used the telescoping arms to apply power and adjust lamp up and down the pipe. We also shown them into a 5 gal. white plastic bucket to make a good soft light.
Practicals often don't have to be at up to full color temperature.
12 volt MR-11s and MR-16 are very efficient units with built in reflectors. They run at least at 3200K, some are bluer with dichroic reflectors. They come in 12 volts with wattages up to 50 watts and 110-volt ones up to 250 watts. Most have very spotty patterns but one has a 45-degree beam pattern. We used Variacs and 12-volt transformers to adjust the output. If you reduce voltage out of the Variac with a 110 to 12-volt transformer your Variac needs to be only 1/10 as large. Make sure that your transformers are large enough. You need a 4-amp transformer to light a 12-volt, 50-watt globe. These globes have at least a 3200 K output at 12-volts and burn for a long time.
There are solid state 110 to 12-volt solid-state units that reduce 110 volts to 12-volts. They are OK, but many need at least a 10-watt load to work and fail at over 50-watts. We tried dimming lights with household dimmers. DON'T. They won't maintain a constant voltage. There are some low wattage 110-volt dimmers that will keep a constant output. You can also reduce voltage with rheostats, and resistors, but high wattage unit are needed. Do your I=E/R and P=IE math. Both types bounced and direct can be a great look inside a miniature set with limited room for lights. Sockets and lights from allellectronics.com. We had no problem with blackening of these globes at lower voltages.
"Grain of Wheat" lights are great for miniature Christmas lights, candles, smaller stars, and practicals. They can be colored with felt tip pens. If too bright use a black pen.
We used white Christmas Tree Lights for star fields. Get the kind that if one burns out it doesn't kill the whole string. We had no burnouts over long shooting times. We drilled holes in a dark blue sky for the lamps as stars. (I made stars for Star Trek in the 60's using about 20,000 watts behind holes in black paper. I still see the same stars occasionally on other shows.)
Fluorescents. These are available in 4-foot Daylight tubes. About 4000K. They can be dimmed slightly without flickering with a Variac or resisters to get tubes to match output. (A 100 ohm 100 watt pot.) We made a bank of them for blue screen with Stewart blue material in front. See (Blue Screen.) Don't dim them much because they will flicker.
A very valuable light is the slide and filmstrip projectors obsolete from the AV industry and slide show needs. They have smooth sharp patterns and can be cut with mattes at the film plane. They are cheap, but globes have gotten very expensive today.
As you know light falls off by the square of the distance from the source. On a large stage or outside in the sun this is not a problem. On a small stage it is difficult to maintain a constant exposure over any distance. Half scrims and CYC lights mentioned above can help, but mirrors can be a great help to effectively get the light farther away from the set and not take up a lot of space. We used three 3' x 4' foot mirrors, backed with plywood and attached them to grip-eliminators to prevent movement during a shot. We used single strength mirror and 3/8 plywood with no problems. Gorilla glue worked fine to attach the mirrors to the plywood. Attach cleats for mounting before gluing the mirror to the plywood.
One-foot square mirrors are sometimes available as decorator items. The beveled ones are much more expensive. Some stores have already framed mirrors at reasonable prices. Going to a glass shop is the most expensive choice, but often the only choice for larger mirrors.
© Copyright 2004 Ron Dexter. All Rights Reserved.