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KnowledgeBase: Source Four Lens Focal Lengths and Field Angles

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First published by:
Kelsey Aleckson
on 06-19-2009
Last revision by:
Kelsey Aleckson
on 07-20-2009
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KnowledgeBase: Source Four Lens Focal Lengths and Field Angles This page is locked to prevent further edits

S4 15-30 Degree Zoom

Rear Lens 206.9 mm
Front Lens 370.6 mm

S4 25-50 Degree Zoom

Rear Lens 125.8 mm
Front Lens 219.8 mm

Here are the calculated FL equivalents for the combined lens sets

 

Fixture Actual Field Angle (per 7/2003 testing) Lens Focal Length
S4 15-30 16.2° minimum 278mm
31.3° max 141mm
S4 25-50 26.9° minimum 166mm
49.0° max 87mm

Fixture Actual Field Angle (per 7/2003 testing) Lens Focal Length
S405 6.9° 658mm
S410 10.6° 427mm
S419 17.7° 254mm
S426 25.1° 178mm
S436 32.7° 135mm
S450 48.9° 87mm

 

 

 

 

Recent Comments

By: georgeg Posted on 09-23-2009 10:35 AM

why are the actual field angles different from the listed field angles? ie posted: 36 degrees, actual: 32.6 degrees?

A person not knowing this would most likely use a multiplying factor of 0.65 rather than the actual .58 and then scratch their heads when the luminaire didn't cover the expected area.

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