Help deciding beam angle for LED Par20 recessed lights

Soupy · Nov 7, 2014

Hello, I am new to LED and need help deciding best lights to order. I am in the process of remodeling my home theater room and installed nine 5" recessed lights. 3 along each side walls (6 total) are eyeball lights. Three down the middle of room are down lights. The Down lights call for PAR20 bulbs, while the eyeball lights call for R20 (but PAR20 can be used). Since PAR20 LED is easier to find than R20 I thought I could order all PAR20. The PAR20's I am looking at will be 12 watt 4x3watt LEDs. They come in 30/45/60/120 Beam angles. My dilemma is that the eyeball lights will be used to light up movie posters that are 2ft x 3ft. I was thinking maybe 30 Beam for those, and 60 Beam for the Down light? I'm using Lutron Skylark dimmer switches for each row. I'm also having trouble deciding on emitting color.I'm thinking warm light will work best for theater room. Any thoughts would be appreciated.

These are the lights I was thinking of ordering http://www.dhgate.com/product/hot-s...dimmable-12w/178482886.html#s1-0-1c|813206617

Thanks,
Soupy

hydro_pyro · Nov 7, 2014

It depends how far the posters are from the lights. You can use basic Trig or an online triangle calculator to determine how much spread you will have at a given distance from the light.

Soupy · Nov 7, 2014

hydro_pyro said:
It depends how far the posters are from the lights. You can use basic Trig or an online triangle calculator to determine how much spread you will have at a given distance from the light.

The cans are 12" from the wall. The top of 3 foot long posters will be about 1 foot from ceiling and are floating about 1" off the wall (french cleat mounting). These are actually movie posters printed on fabric that are wrapped on a frame with insulation for sound treatment purposes. The ceiling height is 7'3". Where can I find such calculator?

brickbat · Nov 7, 2014

Soupy said:
...These are the lights I was thinking of ordering http://www.dhgate.com/product/hot-s...dimmable-12w/178482886.html#s1-0-1c|813206617

Those are suspiciously cheap. Caveat Emptor...

Soupy · Nov 7, 2014

brickbat said:
Those are suspiciously cheap. Caveat Emptor...

I don't know anything about light bulbs. They do have 4258 Transactions and 99.4% Positive Feedback.

hydro_pyro · Nov 7, 2014

You're going to need a wide spread to cover that. Maybe a traditional cloud-diffused PAR bulb would be better, rather than any lensed-type light.

Avoid cheap off-brand lights! They have terrible color rendering. Everything will have a yellow/green hue (for warm) or a dead blue hue (neutral/cool.) I already learned my lesson with these. If you're lucky, you MIGHT get what you pay for.

If you want your posters to look good, find a dimmable cloud-diffused PAR20 LED light with a high CRI rating.

Soupy · Nov 8, 2014

hydro_pyro said:
You're going to need a wide spread to cover that. Maybe a traditional cloud-diffused PAR bulb would be better, rather than any lensed-type light.

Avoid cheap off-brand lights! They have terrible color rendering. Everything will have a yellow/green hue (for warm) or a dead blue hue (neutral/cool.) I already learned my lesson with these. If you're lucky, you MIGHT get what you pay for.

If you want your posters to look good, find a dimmable cloud-diffused PAR20 LED light with a high CRI rating.

What would be considered a high CRI rating? Can you recommend such a bulb please?

LEDninja · Nov 9, 2014

Please stop buying cheap bulbs off the internet. Here is a video showing how dangerous the cheap stuff can be:
Dangerous GU10 LED Spot Light is Cheap and Bright but could Kill You - Seriously - YouTube
http://www.youtube.com/watch?v=keaE7QTKTYE
Watch some of the review videos by electronupdate in this sub-forum. Compare the way proper electronics are built to the cheap 3 element electronics of the cheap bulbs.

Electrical stuff powered off the grid require UL listing or equivalent. UL stands for Underwriter's Laboratory (that is the labs that your insurance company uses to make sure the stuff would not set fire to your house or electrocute you). So your insurance company will get mad at you if you do not use listed approved product. Read the fine print of your insurance policy before using non UL (or CSA or ETL) listed products.
CE is a standard for 220V 50Hz countries. Not 115V 60Hz North America. The cheap stores will list CE to make the bulb look official but it just shows the bulb is NOT designed for use in the USA. Despite the .com I suspect that store is in Hong Kong. I really like they have eyeshadow front and center when I clicked on your link.
BTW your electric utility wants electrical equipment to have a power factor of 0.9 or higher. The cheap bulb in the dangerous video can only manage ~0.64. (Easily deduced from the simple 3 component construction.) Bases on price I do not think the bulbs you are looking at can do any better.

Home Depot carries the Philips BR20 bulbs.

Re: High CRI

The baseline for CRI is the light from a body at a certain temperature. Since that is the way an incandescent light bulb works it is ~100 CRI.

White LEDs are blue LEDs with a phosphor coating turning some of the blue into the other colours making a white light.
In the early days the blue LEDs were not that bright so only a small amount of phosphor was used giving a blue tint. This is still used for daylight white LED bulbs.

Nowadays for most lightbulb LEDs (soft white / bright white) they use more phosphor giving a warmer appearance. Most of these bulbs are ~80 CRI.

Notice the lack of red compared to the incandescent. So some manufacturers add red LEDs. This can raise the CRI to 93 BUT sometimes they add too much red giving the light a pink appearance.

Soupy · Nov 14, 2014

LEDninja said:
Please stop buying cheap bulbs off the internet. Here is a video showing how dangerous the cheap stuff can be:
Dangerous GU10 LED Spot Light is Cheap and Bright but could Kill You - Seriously - YouTube
http://www.youtube.com/watch?v=keaE7QTKTYE
Watch some of the review videos by electronupdate in this sub-forum. Compare the way proper electronics are built to the cheap 3 element electronics of the cheap bulbs.

Electrical stuff powered off the grid require UL listing or equivalent. UL stands for Underwriter's Laboratory (that is the labs that your insurance company uses to make sure the stuff would not set fire to your house or electrocute you). So your insurance company will get mad at you if you do not use listed approved product. Read the fine print of your insurance policy before using non UL (or CSA or ETL) listed products.
CE is a standard for 220V 50Hz countries. Not 115V 60Hz North America. The cheap stores will list CE to make the bulb look official but it just shows the bulb is NOT designed for use in the USA. Despite the .com I suspect that store is in Hong Kong. I really like they have eyeshadow front and center when I clicked on your link.
BTW your electric utility wants electrical equipment to have a power factor of 0.9 or higher. The cheap bulb in the dangerous video can only manage ~0.64. (Easily deduced from the simple 3 component construction.) Bases on price I do not think the bulbs you are looking at can do any better.

Home Depot carries the Philips BR20 bulbs.

Re: High CRI

The baseline for CRI is the light from a body at a certain temperature. Since that is the way an incandescent light bulb works it is ~100 CRI.

White LEDs are blue LEDs with a phosphor coating turning some of the blue into the other colours making a white light.
In the early days the blue LEDs were not that bright so only a small amount of phosphor was used giving a blue tint. This is still used for daylight white LED bulbs.

Nowadays for most lightbulb LEDs (soft white / bright white) they use more phosphor giving a warmer appearance. Most of these bulbs are ~80 CRI.

Notice the lack of red compared to the incandescent. So some manufacturers add red LEDs. This can raise the CRI to 93 BUT sometimes they add too much red giving the light a pink appearance.

Those bulbs I linked state they are UL listed. The case boxes high up on the HD shelves have china printed all over them. That site is a wholesale site which I have bought merchandise to sell on eBay in the past. I wouldn't consider $4.41 per bulb cheap at wholesale. None the less I settled on these bulbs. http://www.amazon.com/gp/product/B00JC5DNS0/?tag=cpf0b6-20 . Thanks for everyone's input. It is much appreciated.

hydro_pyro · Nov 15, 2014

Excellent choice. I installed Feit 93 CRI floods in my kitchen, and I LOVE them. Colors look amazing.

Soupy · Nov 15, 2014

hydro_pyro said:
Excellent choice. I installed Feit 93 CRI floods in my kitchen, and I LOVE them. Colors look amazing.

I got them today and they are great. I'm heading to my local Menards tomorrow to pick up this same bulb but in PAR20. The R20 is working great in areas I want a flood light, and the Par should be great for the lights along the wall for a spot light on pictures.

hydro_pyro · Nov 16, 2014

Like I said, you can use a simple triangle calculator to see how wide your 40° worth of coverage will look at a given distance from the source. You can use the softer floods tucked up inside the bezel to control side-spill while keeping the wide coverage, if the socket depth on your cans is adjustable. The beam on the 40°-lens PAR lights is brutally focused. There's not much of ANY spill beyond the 40°. They will cover your posters from a track fixture several feet away, but from an eyeball can, you may have dark corners on your posters.

Soupy · Nov 19, 2014

hydro_pyro said:
Like I said, you can use a simple triangle calculator to see how wide your 40° worth of coverage will look at a given distance from the source. You can use the softer floods tucked up inside the bezel to control side-spill while keeping the wide coverage, if the socket depth on your cans is adjustable. The beam on the 40°-lens PAR lights is brutally focused. There's not much of ANY spill beyond the 40°. They will cover your posters from a track fixture several feet away, but from an eyeball can, you may have dark corners on your posters.

I returned the eyeballs for more down lights. I swapped the bezels and the down lights actually worked out better at only 12" off the wall. With the eyeballs I had to end up pointing them straight down anyway. I picked up a 50watt halogen PAR20 from HD just to test the pattern and it worked out nicely.

Help deciding beam angle for LED Par20 recessed lights

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