Depends on your application and preference below are some key differences between Jetusolis and Jetue21a:
Jetusolis designed to give the most neutral natural CCT with minimal tint shifting (tightly lies near BBL). No greenish nor pinkish, just neutral.
Jetusolis will give you very consistent CCT and tint across the full current range, a rare feature in LED world. This means it will give you consistent CCT and tint no matter in which mode (low/medium/high) you are without the need to use inefficient PWM dimming.
Jetusolis use Nichia Optisolis (NF2x757GT-F1) LED with higher forward voltage than normal LED. Runtime will be 30% shorter compared to the more efficient Nichia E21A (NVSxE21AT).
Jetusolis optic selection is limited to only 20° and 30° because the asymmetry and dual dies in Optisolic LED.
Jetue21a gives a more pinkish tint than Jetusolis at its highest mode, this makes everything looks nicer. Not for naturalist like me, but it's indeed looks pretty.
Jetue21a has the longest runtime because the E21A LED has low forward voltage. Regulated 80 - 75 lumens for nearly 1 hour without stepping down out of a single AAA battery is no joke. Thanks to the Jetbeam Jet-U sophisticated driver. Few AAA flashlight are this efficient. Please note that the Jetbeam Jet-U host is from the new generation with completely redesigned boost driver.
Jetue21a is visibly brighter. Very bright for an R9080 LED (CRI = 90 min., R9 point = 80 min.).
Jetue21a uniform single die and flat top LED makes it very versatile for almost any applications. You can select 10° optic, OEM optic, 20° optic, 30° optic included in the package to suits your needs.
Both Optisolis and E21A brightness depend on their flux bin.
P9 = 21,4lm - 25,5lm at 65mA
P10 = 25,5lm - 30,3lm at 65mA
But those numbers are somewhat misleading because CW (5000K - 6500K) Optisolis are much more efficient at higher current than its WW (2700K - 4000K). Above 150mA, the CW Optisolis produce output similar to WW Optisolis and the difference keeps increasing as the current goes further up. Check Maukka's test here
This means WW Jetusolis is brighter at Low and Medium mode but dimmer at High mode compared to CW Jetusolis
D160 = 160lm - 180lm at 700mA
D180 = 180lm - 200lm at 700mA
D200 = 200lm - 220lm at 700mA
D220 = 220lm - 240lm at 700mA
D240 = 240lm - 260lm at 700mA
I can't publish each light OTF output individually because those are made to order lights. I don't know how bright it is until it's made. Also, there's variation between LEDs, even those came from the same reel. From our experiences, we can trust Nichia for it's honest and accurate binning with small output differences between LEDs (from the same reel).
For those curious how much output you would get before you decide to buy them, there's a simple way to predict it, so you know what to expect.
Using above data and measured OTF output of a D240 6500K (79,1lm), we can make a better (gu)estimation output of a D160 2000K Jetue21a:
- estimated min. OTF output of 2000K Jetue21a = (160/240) x 79,1lm = 0,667 x 79,1 = 52,76lm
- estimated max. OTF output of 2000K Jetue21a = (180/240) x 79,1lm = 0,75 x 79,1 = 59,32lm
A 2700K Jetusolis will be brighter than 2000K Jetue21a. But 2000K Jetue21a will have longer runtime due to it's low forward voltage.
My advice is to go with Jetue21a unless you really need the ultimate CRI and plan to use it as EDC. A single Jetue21a with 10° optic is my sidekick in my workshop. It's small and light enough to hold in my mouth. Very useful for checking stuff under the car when a headlamp is to awkward to use.
In certain cases such as medical examination/diagnosis, print proofing, forensics, art galleries/museum works, etc... 5000K or 6500K Optisolis is a clear choice. For macro photography a full set of 2700K - 6500K Jetusolis could be an indispensable tool.