Great question, thanks. We have a calculator on our website that allows you to figure this out. It's here: lumicrest.com/beam-spread-calculator/. Using the calculator to answer your question: if the ceiling is 10 feet high and you have the light mounted on the ceiling 12 feet from the wall, a 12 degree beam would give you a circle (oval actually) 2.77 feet in diameter. However, it's not a hard-edged circle; the 2.77 foot diameter is FWHM - meaning Full Width Half Maximum, so at 2.77 feet diameter you have 50% intensity, and the light will fall off beyond that. Note the outer edge of the light beam where (there is no light at all) is not specified, you can't calculate exactly where it will fall off into complete darkness.. Very few LED lights offer a 12 degree beam however. If you are interested in a high CRI Par30 light, Lumicrest offers an adjustable beam angle Par30 with 15-60 degree beam (lumicrest.com/product/pro-series-high-cri-adjustable-lens-par30/) or the Teardrop Integrated Track Head with a 12 degree lens option: lumicrest.com/product/teardrop-shaped-high-cri-dimmable-led-track-head-15w/
What im trying to understand is if the led itself is listed as a 140 degree with no external lens just the led. Then how would you calculate the beam angle having two convex lenses, i would think as in geometry if the led has a 140 deg. angle spread than if you put a lens over it that was an angle greater than 40 degrees than being light cant converge on itself in a magnified route wouldnt anything over the 180 degree mark start over and go from effectively 0 degrees again?? Like if you have a flashlight with a zoom pull/ push deal, if you go too small it starts getting bigger again.. but dunno if youd loose light being refracted within the lens if you were between the 180-360 degree range.. see what im sayn main? In the midst of my left brain waving its fart over to right brain...
Lenses for LEDs are often TIR (total internal reflection type). There are some good resources on the web if you google LED TIR lenses, it may be useful.
So which one did you use as the second example of lighting the picture: the 20 or 36 degree? What was the distance? Couldn't we have seen all three as it seems that that illustration was the most important part of the video. Nonetheless thanks for posting. :-)
Working on a way to do about 5 degrees, but not in AR111 form. AR111 has the additional challenge of sometimes using 12 volt electronic transformers, which are not particularly LED friendly. It's tough to design drivers to deal with all the different types of electronic transformers.
lumicrest Thanks for your response, I don't remember having read it before today. How's things in the factory, has anyone made any AR111 type lamps, yet? Just wondering; I understand the difficulties. I did see a looky-likey AR111 lamp in Soho, but I didn't have my telescope to see what the manufacturer's name was. The light fitting was parabolic, without a bridge of metal covering the lamp from view; the lamp looked like it was "crown silvered" type, note: it was not crown silvered but had some ceramic looking end. The light was shone back into the parabola surface. . It was in a cake shop window display. . I have AR111 lamps in my house for twenty-five years, they are 6 Volt, not 12 Volt. In another part of my house I _do_ have 12 Volt light fittings which use M32 Projector Lamps, covered by a removable "cone", I bought those (10 items) new in 1981, when re-building. . Never changed them to anything else, couldn't find any lamps I liked better. . Thank you Lumicrest for your information. . Cheers. from del-boy.
Thanks for the helpful comment. The bulbs seen in this video have been replaced with newer models, also with switchable lenses, such as our Teardrop LED integrated track head and Modulux LED track head.
thank you so much for making this, it makes it all clear and I couldn't find it easily online. Nice, short, to the point, illustrates pretty well.
They just do that to make me crazy!!!!!!!!!!!
Thanks for the explanation.
Finally, this is the video i need
Thank you sir, u answered my question 😊
Hello would you have a tutorial video similar where including Oval Beam? Thanks
Thanks!
Very helpful video and straightforward!
What do you think about led spot lights with 90 up till 120 degrees= What kind of benefit would that give me?
90 to 120 degrees are wide flood lights, not spot lights. They would give you a very broad wash of flat, even light.
Thank you. that was very helpful.
Thanks for this, help me make a choice buying my leds
Anyone know how to focus a 50w or 100w LED to 20° or less? Nobody seems to have this info anywhere.
Thank you for your help 😇
Thank You. Very informative!
You did not indicate the distance the painting was from you. I need a 3' beam at 12' away. What would be a good choice? thanks
Great question, thanks. We have a calculator on our website that allows you to figure this out. It's here: lumicrest.com/beam-spread-calculator/. Using the calculator to answer your question: if the ceiling is 10 feet high and you have the light mounted on the ceiling 12 feet from the wall, a 12 degree beam would give you a circle (oval actually) 2.77 feet in diameter. However, it's not a hard-edged circle; the 2.77 foot diameter is FWHM - meaning Full Width Half Maximum, so at 2.77 feet diameter you have 50% intensity, and the light will fall off beyond that. Note the outer edge of the light beam where (there is no light at all) is not specified, you can't calculate exactly where it will fall off into complete darkness..
Very few LED lights offer a 12 degree beam however. If you are interested in a high CRI Par30 light, Lumicrest offers an adjustable beam angle Par30 with 15-60 degree beam (lumicrest.com/product/pro-series-high-cri-adjustable-lens-par30/) or the Teardrop Integrated Track Head with a 12 degree lens option: lumicrest.com/product/teardrop-shaped-high-cri-dimmable-led-track-head-15w/
What im trying to understand is if the led itself is listed as a 140 degree with no external lens just the led. Then how would you calculate the beam angle having two convex lenses, i would think as in geometry if the led has a 140 deg. angle spread than if you put a lens over it that was an angle greater than 40 degrees than being light cant converge on itself in a magnified route wouldnt anything over the 180 degree mark start over and go from effectively 0 degrees again?? Like if you have a flashlight with a zoom pull/ push deal, if you go too small it starts getting bigger again.. but dunno if youd loose light being refracted within the lens if you were between the 180-360 degree range.. see what im sayn main? In the midst of my left brain waving its fart over to right brain...
Lenses for LEDs are often TIR (total internal reflection type). There are some good resources on the web if you google LED TIR lenses, it may be useful.
Very helpful, thanks!
Tank you
Thank you!
very helpful
how much coverage in sq. ft. one gets from a 30 degree lens when lit from a distance of 3 meters?
Our website has a calculator that allows you to check light coverage based on lens angle here: lumicrest.com/calculator-tools/beam-spread-calculator/
So which one did you use as the second example of lighting the picture: the 20 or 36 degree? What was the distance? Couldn't we have seen all three as it seems that that illustration was the most important part of the video. Nonetheless thanks for posting. :-)
Very good gratitude
good job. thanks
thanks, good video
60 degrees for home use
i know this is old video when no intro and ads.
2024 thank you!
What about Beam angle: 4 ° ?
When will LED be invented to replicate / replace AR111 lamps ?
.
Anyone.
.
.
Nice video
Working on a way to do about 5 degrees, but not in AR111 form. AR111 has the additional challenge of sometimes using 12 volt electronic transformers, which are not particularly LED friendly. It's tough to design drivers to deal with all the different types of electronic transformers.
lumicrest
Thanks for your response, I don't remember having read it before today.
How's things in the factory, has anyone made any AR111 type lamps, yet?
Just wondering; I understand the difficulties.
I did see a looky-likey AR111 lamp in Soho, but I didn't have my telescope to see what the manufacturer's name was.
The light fitting was parabolic, without a bridge of metal covering the lamp from view; the lamp looked like it was "crown silvered" type, note: it was not crown silvered but had some ceramic looking end.
The light was shone back into the parabola surface.
.
It was in a cake shop window display.
.
I have AR111 lamps in my house for twenty-five years, they are 6 Volt, not 12 Volt.
In another part of my house I _do_ have 12 Volt light fittings which use M32 Projector Lamps, covered by a removable "cone", I bought those (10 items) new in 1981, when re-building.
.
Never changed them to anything else, couldn't find any lamps I liked better.
.
Thank you Lumicrest for your information.
.
Cheers.
from
del-boy.
Lights name?
Useless common sense. No link for these bulbs either. Wow a wide angle is wider than narrow, thanks captain obvious.
Thanks for the helpful comment. The bulbs seen in this video have been replaced with newer models, also with switchable lenses, such as our Teardrop LED integrated track head and Modulux LED track head.
Very helpful, thanks!