Be aware that the flux (output) of royal blue LEDs is often specified in radiometric terms, not photometric terms. At 50 mA, typical luminous flux is acknowledged as 20 lumens and vape juice typical voltage drop is acknowledged as 3.1 volts, Vape E-Juice which works out to 129 lumens/watt. Assuming sometimes 15.6 lumens with typical voltage drop of 2.62 volts at one hundred mA, this works out to usually 59.5 lumens/watt at a hundred mA. This works out to 169 and Vape Devices 165 lumens/watt respectively.

Replace 11/24/2024: vaporover (https://www.vaporover.com) Lumileds L128-4070SA35A00F1 typically produces 40.6 lumens from sixty five mA of present with a typical voltage drop of 2.7 volts which works out to luminous efficacy of 231 lumens/watt. My test results are solely about 3% brighter with about 1% extra voltage drop, with conservative common of 102 lumens out per watt in at 20 mA. Osram GW Q9LR34.PM-M5N3-XX53-1-45-R18 and GW Q9LR34.PM-M5N3-XX55-1-45-R18 are claimed to sometimes produce 265 lumens at 45 mA with a typical voltage drop of 22.1 volts.

The voltage drop can also be .1-.2 volt much less at 5 mA than at 20 mA. Update 3/24/2013 This 3/19/2013 LEDs Magazine article (now at the Wayback Machine) mentions a 2700K Samsung LM561B-family LED achieving 130 lumens/watt at a hundred and fifty mA, and vaporover 150 lumens/watt at a lower current, with 65 mA mentioned as a lower current for higher effectivity in one other LED on this collection.

Overall luminous efficacy is usually about 30-50 percent extra at 5 mA than at 20 mA for inexperienced and blue InGaN LEDs characterized primarily at 20 mA, Vape Starter Kits and usually 35-60% more at 3 mA than at 20 mA.

This is at junction temperature of 25 C; count on a p.c or two less with good heatsinking. This is with junction temperature of eighty five C. Expect strangely about 6% much less with thermal pad temperature of 35 C, assuming the unusual blue curve in Figure 2e of the DS144 datasheet is appropriate. Now for low power blue LEDs: Update 10/15/2020: vaporover Cree C503B-BCN-CX0Y0451, in my testing of 7 samples, had conservative dedication of typical general luminous efficacy/effectivity of 31 lumens/watt at 20 mA.