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Old 05-30-2018, 09:51 AM   #56 (permalink)
oil pan 4
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LEDs don't produce white light either so I don't know what you are talking about there. Virtually all "white" LEDs create blue and/or UV and use phosphorescent material to make the light whiter. The only time you get the color of light created from the LED is if you want a specific color. You can get white LED light by combining red, blue and yellow but this appears to be very uncommon for making white light for residential/consumer and commercial applications.
Do you not understand how these work?
It looks to me like you don't understandwhat you are talking about, yet again.

Also how am I to compare room lit lux value of product that is still in a box on a store shelf to another product on the shelf, then compare those to what I already have? Sounds like "you have to buy it to find out" marketing BS to me.

I wasn't measuring lumens per watt I was measuring lumens per volt•amp which takes into account power supply inefficiencys which is where cheap LEDs lose big time.
Industrial commercial florescent light ballasts typically run about a .99 power factor. Cheap consumer ballasts run a much lower power factor, putting the lumens per volt•amp on par with cheap LEDs.

The T5 tubes typically don't make 100 lumens per watt, they make between 92 for high output and 106 to 111 for standard output on high efficiency ballast.

LED chips by them selves are very efficient for a single color, 150 to 200 lumens per watt are common now, with around 346 lumens per watt being 100% theorized efficiency for green light. But they can't come any where near that on white LEDs because, blue and UV light used to make white LED lights tends to be less efficient than other colors, phosphorescent limitations, other quantum physics level limitations only discovered only discovered after people tried first making very high intensity LED chips and the nature of the cheap garbage coming out of China.
I'm seeing LEDs over here that typically do between 50 and 65 lumens per volt•amp on the cheap ones and between 80 to 100 lumens per volt•amp on the good ones which are usually more than double the price than that of the cheap ones.
Still this is a big improvement over compact florescent which was only doing around 35 lumens per volt•amp.

Quote:
Originally Posted by Crashy View Post
I've sold $2m of LED over the last 8 years.
Lumen output is not the way to compare one bulb to another. You need to measure the lux falling onto the objects in the room. Leds are directional which means less lumens required to give the same lux. The purpose of a bulb is not to have you stare directly at it and be blinded...the purpose is to illuminate objects you want to see.
6000k is daylight (literally) so if you prefer 3000k it's because you are used to lousy yellow distorted light which decreases color depth, contrast and perceived brightness.
A T5 does not produce white light, it produces UV (and infrared) which gets converted to white light through the phosphorus (and a great deal of IR and UV escape the tube). This requires a gas to be HEATED. Infrared is the primary wavelength with UV being secondary. Obviously this is very inefficient.
I call bs on 100lm/w.

Leds ARE more efficient because their primary wavelength is already the required wavelength, no lossy conversion is required. No UV is emmited out of the bulb and very little infrared, which is easier on the eyes.
Early leds did produce UV which was filtered through a phosphorus dome. I have not seen these in 6 years, and only at the bottom end of the market. If that's what you want to buy I have no sympathy for you.

Last edited by oil pan 4; 05-30-2018 at 10:25 AM..
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