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Community and Q&A

Beam Angle

cbut8995 | Posted in General Questions on

Does Beam angle for recessed lighting matter much when the ceiling height is 8 foot only and, both the same lumens, and the lights are only 4 feet apt anyways in the ceiling?

I have 2 options for lighting

Option 1: 4inch, 40 degree beam angle 1100 lumen that has the LED chip exposed (contractor say they give a richer nicer glare, not even sure what that means to be honest as I cant find much info on this compared to the slim normal ones from HD).

Option 2:  6 inch, 110 degree beam angle. 1100 lumen frosted light look WITHOUT exposed LED chip


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  1. Expert Member
    BILL WICHERS | | #1

    I hate glare, and I try to keep the LED part of the fixture recessed up far enough into the can that I don't have glare from the sides. That's my personal preference though.

    The beam angle will tell you how bright of a spot (in lux) your fixture will project from it's illuminating power (lumens) at whatever distance you need to know. You have to do a bit of trig to work it out is all. The angle and the height will give you the area of the projected 'spot' of light, and you can work out the lux level from that area knowing that 1 lux = 1 lumen per square meter (one square meter is approximately 10.76 square feet).

    Rather than doing all that math though, it's easier to just cheat and look for an online calculator. I found one here:

    With the small spacing of only 4 feet, a narrower beam angle probably makes sense. You'll get some overlap of the projected patterns even with the 40 degree beam angle, which means the lighting levels will partially add (be brighter than a single fixture by itself), and cut down on shadowing a little. I'd try to find something without the exposed LED, but that's just me.

    If you use the wider beam angle, you'll have more spread between fixtures. This would not matter much if the lights were installed in a grid pattern all over the ceiling, but if they're in a straight line, you'll end up with a much wider, and somewhat dimmer, band of light.


    1. cbut8995 | | #2

      Thanks Bill, Always a big help. Do you happen to have pictures or what the exposed LED chip would look like. I believe the apt I currently live in has the flat color recessed lighting.

      Its a premium my contractor is charging me for the exposed LED chip since "nicer richer glare" but all lights will be facing down anyways. but I cant seem to find any stuff about the difference between the normal flat LED lighting vs these exposed LED chip ones.

      1. Expert Member
        BILL WICHERS | | #3

        If it's a stock fixture at HD, go eyeball it in their display. Otherwise see if you can find one in a showroom somewhere to look at. I don't have any pics myself, although I have an idea of what it probably looks like. I would compare it to one of the old mini-size halogen lights with the dichroic reflector. Those were dazzling with glare if you looked at them off axis. I've always liked to have some type of system to limit off axis light from bright fixtures so that they aren't blinding as you walk by.


  2. Expert Member
    Akos | | #4

    For fill lighting you always want very wide cone. Some companies even make LED slim lights specifically for this purpose:

    The taller the ceiling the less this matters. I've had no issues using gimbal LEDs with 12' ceilings.

  3. charlie_sullivan | | #5

    It really depends what you want the light do do. Do you want the floor illuminated, and you'll use something else to light the walls? Or do you want general illumination all from those lights? Do you mind if the ceiling looks dark?

  4. tech1234 | | #6

    Some great info on this can be found here: BS+Beer show

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