What is a ThingM?
ThingM is a camera motor control for shooting stop-motion animation, time lapse, optical printing, or other single-frame filmming technique. It is capable of shooting a frame at a time at variable film speeds and exposure times. ThingM automatically changes film speed for selected exposure time according to the shutter angle opening of the camera. Wedge exposure sequences are even available for shooting tests in half-f/stop increments. Pre- and post-exposure trigger signals allow for interfacing to other accesories, such as lamp relays, strobe lights, or video capture devices. These and other features are available inside the ThingM controller unit, since they were originally adapted from the ANIMAL motion control program for desktop computers, and re-written in microprocessor code.
ThingM is designed particularly for stepper motors, which are inherently digital by nature for rotating in discrete angular increments, or steps. Stepper motors are so precise, that they are frequently installed without feedback devices, like rotary encoders or sensing switches. In fact, professional camera operators at Skellington Productions, Danger Productions, and Will Vinton Studios, manually align the motor drive shafts on their 35mm Mitchells after loading film, and then rely on ThingM to run perfect 360-degree revolutions for shooting their single-frame exposures. (The ThingM-LX is their model of choice.)
One significant performance advantage over other stop-motion motors is that each revolution is run with ramped acceleration and deceleration. That is, the first 90 degrees of rotation graduallly accelerates the motor to the selected film speed before the shutter opens, and the last 90 degrees decelerates to a gentle stop after the shutter closes. This ramped operation results in smooth starts and stops for camera drives, especially heavier 35mm cameras. Constant speed AC motors and single-speed DC servo motors have abrupt starts and stops by comparison, which can be unsettling for both camera and operator.
Another noteworthy comparison is ThingM's field use (model ThingM-LC). It can be operated from a 12-Volt battery supply, like a car battery. (An adaptor can use the cigarette lighter for connection.) Of course, an AC motor is no good in the field unlesss you have a DC-to-AC inverter. But if you've used one of the other manufacturers' DC servo motors in the field, you will have experienced the irony of the motor speed -- and hence exposure time -- changing over time as the battey runs down. No such irony happens with ThingM's stepper motor drive, since rotational speed is independent of voltage level. (When the battery runs down below its useful capacity, the motor just won't turn anymore.) Power consumption is only significant when the motor is actually turning the camera shaft during exposures. Substantially less power is consumed during time lapse intervals inbetween exposures when the motor is at standstill.
While the single-motor ThingM controllers are able to trigger external devices via a logic-level signal, the ThingM-II dual-motor controller is available for applications requiring a 2nd motor to run sequentially with the camera. Actual implementations include JK optical printers, animation stand pegbars, and tripod panning head. Synchronous operation has also been employed for double-system stereoscopic camera drives. The ThingM-II also provides a serial interface for remote control operation from an external computer, which can be used for custom camera sequencing or auxiliary motor incrementation.
Contact Dave Milici at Ironic Research Labs via email: davem@ironicresearch.com