Counterbalanced Image Stabilizer

Counter-Balanced Image Stabilizer

 


      This camera-shake compensating mechanism works passively and requires no electrical power, gyros or warm-up time.  It was developed by Steve Hines at the Kodak Research Laboratories in 1977 and is the subject of U.S patent U.S Pat. 4,290,684 which is assigned to Eastman Kodak.


 

      The image-stCounter-Balanced-Camera-Stabilizer-02-250pabilizer in a clear camera body, showing the lens, film and holder, and three parallel support rods.  The rods are supported by an intermediate frame (shown in clear Plex at left, and in blue in the animation below).  The lens and film counter balance each other on opposite ends of the three rods which are the same length as the focal length of the camera lens, so as to not over or under correct image smear. 

      If hand shake causes pitch or yaw motion, inertia causes the lens and film to lag behind at their original angle.  The parallelogram legs allow the camera housing to rotate around the internal camera parts.  The system is in equilibrium at any angle.


 

When the the camera body pitches up or down, or yaws left or right, inertia causes the mechanism’s support legs to remain at their previous angle.  As a result, the lens remains on a line between the object and its image on the film. 

The camera in this animation is tilting through an exaggerated ±5° angle for illustration, however virtually all camera shake occurs within ±1°.

 


 

Pitch

or

yaw 

Defocus*, mm standard mechanism

(smaller is better)

Defocus*, mm Hines’ mechanism

(smaller is better)

0.0 0.0
1.15 0.015
2.3 0.061
3.46 0.137
4.62 0.224
5.9 0.381

*Change in lens-film distance, measured 57mm off axis, and based on 100mm focal length lens.


 

What it provides:

      Any movement can be described with translational and rotary motion.  Camera motions which have the most serious effect on image smear, are pitch and yaw.  The camera tipping down 1°, has the effect of an object at 50 feet, being lifted 10 inches.  This shake-mechanism compensates for five times this amount in both the pitch and yaw directions.


  

      This mechanism can withstand, but is not affected by, translational motion (ex.: bumping).

CmraStblzr-3_Leg_480p

 

      The mechanism connects the rods to the lens board and film holder with agile cone-and-cup supports (the 2-axis version of a knife-edge hinge).  

      The mechanism is caged when not taking a picture, allowing the mechanism to float during exposure but otherwise be locked.


 

The concept applied to a 110-format camera:

       Here, the film is stationary and the lens is counterbalanced with an offset added weight.  


 

      This is not a product for sale.  This project is shown only as an example of past engineering by Steve Hines who currently offers consulting in the area of opto-mechanical equipment design, as well as a variety of licensable technologies.

 

HinesLab

Glendale, California, USA

email: Steve@HinesLab.com

Phone: 818-507-5812