An Animated Fireplace
We wanted a real looking fireplace in Davey's living room. We shot tests of real flames with the Nikon D-100 to determine the shutter speed and exposure necessary to get a sharp image of a moving flame. We found that a 1/400 sec. or shorter was needed. We made a butane flame bar out of 1/2 water pipe with holes for an appropriate looking flame. We shot a test at 90 FPS on the Mitchell with a 45 degree shutter (1/400) on ASA 400 film at F 1.4. (Just enough light.) It looked great. We enlarged the holes toward the ends of the pipe to provide a flame of consistent height above the pipe for the final film.
We made a 2 foot long loop of the flame daily print that we cycled through a Dukane 35 mm film strip projector frame by frame. (Film strip projectors are 1/2 35 mm still frame with 4 perforation pull down like motion picture film.) The print was projected on a 4 x 5 ground glass screen in the back of the fireplace. We used a plastic negative (wide angle) fresnell lens made for a camper back window to make the image viewable from different angles other than straight on. We made logs of clear plastic rods that imaged the flames through the logs. (The image was reversed top to bottom like a lens, but was OK.) We also provided a fire flicker light from the side for objects close to the fire and for other shots that didn't look directly into the fireplace. Lamp voltage changes from a Variac provided frame by frame flicker.
We had some problem with keeping stray light from the set off of the ground glass screen in the back of the fireplace. A D-100 test and spot meter check assured us that what we saw by eye wouldn't show on film.
These Dukane film strip projectors are obsolete but available in 150 to 750 watt units on Ebay for not much money. They are great high quality focal spots. Putting them on a bale like a studio light makes adjusting them easier. We didn't use them this way but I have used them a lot like this before. We intended to use the projectors to light fiber-optic pipes for small Christmas lights, but we ended up using grain of wheat globes colored with felt tip pens.
Many scenes in animation like computers, TVs, etc. can be projected this same way.
I also used a 500 watt slide projector as a lamp house for our WW II vintage 35 mm daily projector. Before getting the projector we used a Moviola, but risked scratching the film. If the negative getd loss you still have the daily print if it is not damaged.
© Copyright 2004 Ron Dexter. All Rights Reserved.