Known stage lighting fixtures comprise a casing extending along a longitudinal axis; a light source housed inside a closed end of the casing to emit a light beam substantially along an optical axis; and beam size adjusting means positioned to intercept the beam.
The beam size adjusting means adjust the size of the image projected by the lighting fixture, and normally comprise a zoom device defined by a plurality of movable lenses.
Increasing demand for more compact stage lighting fixtures, however, makes it necessary to minimize the size of the beam size adjusting means.