What is a Fixed Beam?

As the name suggests, a fixed beam / fixed focus is an ellipsoidal which produces a single beam angle. The action of moving the lens/es moves the system in or out of focus altering the beam edge between hard (in focus) and soft (out of focus).

This is the favoured type of ellipsoidal in North America due to their simplicity of operation.

Significant light can be wasted with the masking shutters when they are used to significantly reduce the beam size.

Diffusion Frost is often used to ‘smooth' the beam edges into adjacent beams and/or even out the beam distribution due to the inability to effectively alter the light distribution over the beam or due to poor lamp alignment. The use of diffusion further reduces the light output.

Stephen C. Litterst, Technical Director at Ithaca College, NY provided this piece of background from the College's production of Cosi Fan Tutte, (left) where their Pacific 90° Fixed Beam was used to light the largest ceiling piece.

"Ithaca College purchased their first Pacific 90° primarily as a teaching tool.  However, when the time comes to talk about the latest technology in spotlights, the unit is almost always in the air.  The Pacific was the perfect answer when lighting designer Steve TenEyck wanted to top light a large ceiling piece in a recent production of Cosi Fan Tutte.

A combination of short throw distance, and inaccessibility demanded not only the 90° beam spread but a dependable fixture we could focus and forget. Designer Steve TenEyck commented, "The translucent ceiling was so close to the grid, that only one fixture in our stock would do the job. With that distance it worked out just fine."