THE SMA FORUM ARCHIVE
Posted by Brickfilms, on 2001-05-12 00:38:35
What does everyone here use for minature lights for set construction? I'd like to light some things from within, and need very small lights to do this.
Also, a light I could use for a "streetlight" type set piece, so something very small.
I thought of fiber optic, but where would I purchase this?
Posted by MovieStuff, on 2001-05-12 10:46:07
If you are using long exposure, LED's are the best, in my book. they use practially no power, don't get hot and last for-ev-er. Whereas bulbs need to be mounted to allow for eventual or unexpected replacement. LED's last for years, even under continuous use. Therefore, they can be simply glued in place. Radio Shack makes a variety in different colors. Just make sure you get the ones with the dropping resistor built in or you'll burn out the LED.
Posted by Nick H, on 2001-05-13 02:47:52
I found LEDs too dim to match with my other lighting, so I use small globes. Depends on the other lighting, it's relative brightness that matters. I tried a little 12v 20 watt halogen for a streetlight, but it was too bright and very hot. I stick to 12 volts, so I can run everything off one transformer, but I'm using lower wattages, around 3 watts I think for a streetlight. The globe is a little screw-in type,the size of a flashlight globe, so it can be unscrewed from the mount. My 1:24 car headlights were smaller, actually Bezels or coloured indicator lights, with the coloured plastic dome removed. The tail lights are very tiny, the globe comes with 2 wires attached, coated in plastic insulation. I paint red stainglass paint directly in the globe. (I've just added some images to my Good Riddance album at my www.Picturetrail.com/Hilligossnic site, including one night shot, but the house is lit from inside by a compact flouro globe, the kind that fits a normal incandescent socket. It'd as big as a normal 75 watt lightbulb, but doesn't get hot. I don't think there are any of my little lights showing.) I looked through all the bins at Dick Smith Electronics and Radio Parts stores (similar to Radio Shack) to see what I could use.
Posted by MovieStuff, on 2001-05-13 20:17:11
I guess I got spoiled having a capping shutter on my animation camera. When I use LED's, I just do a secondary burn for the them to balance the exposure before moving on to the next frame. But you are right, they are no terribly bright compared to tungsten lights and the such. I just like them because they're convenient, last for ever and don't get not. But I guess convenience is relative to the equipment one is using. If I didn't have a capping shutter, I wouldn't use them either!
Posted by Nick H, on 2001-05-13 22:49:04
Moviestuff, The point about getting hot is a good one. The headlights in my 1:24 Morris van had to be switched on just before the shot and off again, because the front of the van was vac formed from styrene and softened pretty quickly from the heat. Many of the house roofs are also styrene, that's why the flouros. So, with your secondary burn, do you set the film advance to stop in the open shutter position, do a quick exposure with regular lighting with the capping shutter, then turn off all lights except the LEDs for the second, longer exposure? I've often read about multiple passes with motion control, but the beauty of your system is that you can do all the passes for each frame before moving on to the next one, so you can have puppets or camera in motion without worrying about whether it's repeatable. I'm getting an acceptable result with a single exposure, but there is a degree of compromise.
Posted by JohnL, on 2001-05-14 00:42:45
[font size="1" color="#FF0000"]LAST EDITED ON May-13-01 AT 10:43 PM (PST)[/font][p]Im also making a street lamp just using a tourch globe. To stop it from being to bright im painting the glass of the lamp white. And any light thats supposed to come from the lamp its being lit externally.
Posted by MovieStuff, on 2001-05-14 07:45:08
[font size="1" color="#FF0000"]LAST EDITED ON May-14-01 AT 05:47 AM (PST)[/font][p]Nick:
I modified my Bolex to stop with the shutter open and the advance claw engaged to increase registration, which was already pretty good. Then I mounted an external Copal capping shutter hooked to a digital darkroom timer. The timer is repeatable so I don't have to reset it after each shot. A motorized Cramer switch is used to sequence everything. When I press the button on the Cramer switch, it activates as many as 8 micro switches in sequence. In a typical set up, it would activate the shutter, then the camera advance, then maybe some sort of mover like an animation compound, etc. Then it returns to the "home" position. The next time I hit the button, it runs through the programed cycle again. That way, I don't forget anything!
In the case of second burns for small lights, if the camera isn't moving and nothing passes in front of the lights, then I simply rewind the film and do a second pass with the exposure set for a longer duration to burn in the lights. However, if the camera is in motion and/or something is passing in front of the LEDs, then I do a second exposure before moving on to the next frame.
Depending on the length of the exposure required for the stage lighting, there are two ways I approach this.
1) If the beauty lighting on the stage is low and my exposure is long, around 5 seconds or more, and the exposure required for the LEDs is longer at, say, 15 seconds, then I could use the Cramer sequencer to simply kill the stage lights after 5 seconds. The shutter would stay open while the LED's continued to burn for an additional 10 seconds. Then the shutter would close, the camera would advance and the Cramer switch would bring the stage lights back on. Again, the Cramer sequencer would cycle back to "home" and wait for me to press the button again.
2) I would use a second darkroom timer set at a different exposure to kick the capping shutter a second time (after killing the stage lights, of course.) This would be used if the primary exposure were too short to control by killing the lights (say, around 1/60th of a second). As you know, turning lights on or off to control exposure on short durations can cause problems in shifts in color. The longer the exposure, the less of a problem this is. So, the first timer would make the primary 1/60th exposure, then the lights would go off, then the second timer would make the 15 second exposure for the LED's. Like before, the lights would come back on, the camera would advance, and everything would be ready for the next go.
Cramer switches are cheap and VERY handy!
Posted by Nick H, on 2001-05-14 19:40:33
I've never heard of Cramer switches. I have to do everything manually, and when that means turning lights on and off, moving the camera, moving a prop, remembering to keep a flashing light on for 15 frames, then off for 15 frames, and animating 2 or 3 puppets, stuff-ups can become the rule rather than the exception. Where do you get these motorized Cramer switches? Are they mains power? Would they work with 240 v AC 50 cycle power, or only US 120 v AC?
Posted by MovieStuff, on 2001-05-14 20:23:34
The term "Cramer" refers to the brand name; basically the only people that ever made these things. They were used a lot in industry back in the 50's and 60's. If you can imagine a shaft with positionable cams that activate a row of heavy duty micro switches on either side, that pretty much sums up a Cramer switch. The cams are adjustable as to when they "hit" and, most importantly, how long they keep the switch engaged. Also, the switches have two contacts; normally open and normally closed. So you can have something normally on, like room lights, then have them go off for a short time based on the setting of the adjustable cam or vice versa.
They are butt-simple to use and come with two little adjusting wrenches for changing the timing on the cams.
The motor that is mounted on them is removable, leaving a very handy, standard 1/4 inch diameter shaft to connect to your own motor. The other end of the cam shaft sticks out with a dial knob mounted for easy manual turning of the shaft.
I used a simple, 12 vdc DC gear motor made by Dayton. It also has a 1/4 inch shaft, comes in a variety of gear ratio/speeds and has convenient mounting holes. The Cramer switch is about $35-$45 dollars, U.S. and the motor is about $40. In all, the set up runs about $120-135 to build out, depending on how the control box is built out. I have mine set up to do a complete cycle as well as a "split" cycle. The split cycle stops the shaft after only half a revolution. This allows for two different "patterns" or the same pattern repeated again. This is handy to shorten the cycle time of the switches. A little more trouble to build out, but boy is it worth it!
Hey! Want me to build you one? I could whip one together in less than a day. Contact me off list at