I am currently thinking of purchasing high bay UFO LED lights and in the drop down menu I can select what kind of reflector I want. What does 60deg 90deg 120deg actually refer to?
Help me visualize "Degree of Light"
- Thread starter Fordiesel69
- Start date
It refers to how wide the light beam is. 120° is wider than 60°.
Yes beam width but it's only generalizing, subject to the way the rating was achieved. This is often intended to mean the beam intensity before dropping below some threshold value meaning there is still spill of light outside that beam angle, and depending on reflector and lens design, sometimes quite a lot. There is usually far more spill with a traditional reflector design, compared to adding or replacing with a collimating lens.
I'd pick based on how far off the target illuminated surface they'll be placed, and how many per square foot of space they need to cover, so with the rated beams width each has some overlap with the next light.
I'd pick based on how far off the target illuminated surface they'll be placed, and how many per square foot of space they need to cover, so with the rated beams width each has some overlap with the next light.
What does your photometric calculations say you should be selecting?
It refers to the “cone” of light it puts out. If you put say a 60° light too close to the ground you’ll have spotty lighting, whereas if you put a 120° up too high it’ll be far too spread out and be dimmer looking than it should be.
Pic for example.
Pic for example.
OK I now understand. So changing from a 90 deg lense, to a 120 deg lense will increase the lighting circle diameter at the expense of a little less light.
It's not a little less light, it's a significant difference in the perceived light output. A 1000 lumen light spread out over a 10' circle vs a 20' circle is a lumens/square foot change by a factor of 4
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