Zoom Lens for Motion Picture Cameras with Single-Barrel Linear Movement

Frank G. Back

Previous varifocal lenses used two or three movable components which had to be shifted against each other. This movement was necessarily nonlinear and therefore had to be achieved by nonlinear cams. This presented many mechanical difficulties and it was nearly impossible to obtain an accurately focused image over the entire range. In addition, the shifting of the movable components against each other caused numerous aberrations. — The new varifocal lens has only one movable barrel, and the compensation of the image movement is achieved solely by optical, and not by mechanical means. Therefore, the lens gives a well-focused image sufficiently free from aberrations at all positions.

Print ISSN
Published
1946-12
Content type
Original Research
DOI
10.5594/J12747