I avoid Sofirn’s dive lights as they have the annoying 3 minute step down to a ridiculously low Med setting. There’s not much use of it diving. You need a steady high output to illuminate your surroundings underwater
I just got an SD03 in today’s mail.
Bought it because (a) affordable, and (b) my first light with a magnetic control ring
Decent yellow spot, some flood around that, and a blue ring at the extreme outside edge of the illuminated area.
Looking from behind the light, turning the ring counterclockwise from Off it’s Low, Med, High, and off again.
Clockwise from off is High, Med, Low and back to Off.
Feels solid, like a potato masher grenade.
I don’t get a stepdown at three minutes (I was patient up to about five minute mark).
Maybe it’s a temperature rather than a time based change? it could just be I’m in a rather cold house ….
@ hank:
Originally had my sight on the SD03 as it didn’t seem to have the timed step-down. Sofirn informed me of unavailability and offered the SD05 with discount.
The SD05 has timed throttling - quite stupid given it’s a watercooled light and in ambient air has thermal control.
Here are my results (using a phone’s light meter and my standard* for conversion);
First 3 minutes 316 lux -> 1150 lumens (steady output)-
at 3 1/2 mark 286 lux -> 1050 lm-
at 4 minutes 246 lux -> 900 lm-
Edited (⌃had not fully charged the battery⌃):
at start - 772 lux -> 2830 lumens
at 1 min - 765 lux -> 2800 lm
at 2 min - 684 lux -> 2500 lm
at 3 min - 542 lux -> 2000 lm
at 4 min - 318 lux -> 1150 lm
at 5 min - 264 lux -> 950 lm
Temps in the 40º to 44ºC. I was curious so I fetched it from the car, which is –10ºC (~25ºF). I added an open celled neoprene glove around the shank, too cold to handle bare hand.
- Don’t have a Mauka calibrated light but a RayoVac alkaline stated 382 Lumen unit. Been my standard for some time as gives ballpark values.
But the ring switch is very practical - no fumbling about to turn on.
Since then, I purchased a Wurkkos WK20S (identical construction to the SD02) albeit an XHP35 HD emitter (the Sofirn’s using XPL - both at 5500ºK). The switch is soft and very enjoyable. The throw with spill is quite good.
Never took them apart, notoriously glued - using as is out of the box.
>unavailability
Eh? It’s still for sale:
@ Hank:
Unavailable when I initially ordered some 5 months ago (Aug. 8th ’19). Came back in stock after a week but as I said, Sofirn made a good discount for the SD05
I have to confess, I like the 03 shape and simplicity.
If I get a few more of these, they could become my favored lending-out flashlight. Hard to lose, easy to recognize.
Tested the output at 30 seconds and Sofirn got it pretty accurate this time.
Low - 78
Med - 348
High - 832
The SD03 just went on sale (closing out old stock?) at Ali
$12.04 plus $1.16 shipping (which I guarantee will be slow, as I’ve had orders stuck somewhere between China and California for a long, long time)
https://www.aliexpress.com/item/32825380664.html?mp=1
PS. it appears they don’t combine shipping if you order more than one. They do pop up what claims to be a discount coupon if you buy.
I couldn’t make that coupon thing work at all (Firefox). But if you want several, you might try buying one, and see if you get a $2 coupon “for your next order”
Better be quick as I’m grabbing 50 out of 60 left
The first 4 shipping options Ali offers for NL are free. Remember, you don’t have to be a diver to buy this light. I think these are great outdoor “all weather” lights. Something I would not say about a flimsy “tactical” zoomie. And the size and weight of this thing should be quite reassuring when walking the dog at night.
Just grabbed one. Thanks for the heads up!
Are they for divers?
Are you joking?
I’m not entirely sure what purpose my customers use them for.
No, I resell them 
Ya know, BLF ought to try to qualify as a dealer/middleman to capture some of the discounts offered to resellers.
Just sayin’.
Funtastic wrote in the SD05 thread:
Burns a bit, don’t it? But hey, “the more you pay, the more it’s worth.”
More discussion of the SD03 continues in that SD05 thread.
Ah, I missed the triangle indicating a pulldown menu for shipping options, but they’ve preselected the least expensive for my orders (Singapore Post, $1.16 for a single light)
I should mention that price excludes shipping price and only express is available so it’s only cheap for large quantities.
As a reseller I hardly get much of a discount but because this item is discontinued it’s a different story. Prices usually equal a group buy price
What do y’all think about putting a little bit of lubricant into the grooves of the switch ring, to hopefully keep grit out?
One problem I can foresee with this design is cleaning out the moving parts eventually.