[Review] Sofirn SD05 Diving 21700 Flashlight

Disclaimer: I was kindly offered the Sofirn SD05 Diving Flashlight for review. Amazon link (non-aff)



General Info:
The Sofirn SD05 is a new diving flashlight, powered by a 21700 battery. It uses a neutral-ish Cree XHP50.2 LED. It has 3 brightness levels controlled by a magnetic ring around the head.



Fit & Finish:
The quality of the SD05 is great. The anodizing is has a nice, satin feel to it. It has a good solid heft to it. The threads are square and smooth. The battery tube appears to be glued to the head. The bezel is glued on, which I removed for the sake of investigation (I warmed it up a bit and twisted hard with a rubber grippy pad). The glass is thick and has o-rings on both sides. The magnetic control ring is easy to use and has very definite “clicks” for each of the three modes (plus off).



Modes & Runtime:
table(table#posts).
||High|Medium|Low|
|Estimated lumens|2910|1017|350|
|Spec’ed lumens|2550|900|300|





Waterproofing:
Honestly, I’m not a diver. But one of the main selling points of any diving flashlight surely has to be great waterproofing. Based on the thick glass with double o-rings, glued head, and double o-rings in the tail, I’m inclined to think that this is pretty waterproof. For an initial test, I turned this on and sank it to the bottom of my fish tank. My fish tank has nowhere near the pressure that you’d get while diving, but it’s a start. I’ll be going on a fishing trip in the upcoming weeks and I’ll sink it in a nice, deep part of the lake for a while and will report back with the results.



Misc Info:
This came packaged in a relatively plain cardboard box, but contained everything you’d need to run it: the flashlight, a Sofirn-branded 4000mAh 21700 battery, and a USB charger and cable. It’s a basic charger, but it works just fine. Overall, a great kit for the price that Sofirn is asking.



Beamshot: it’s a modern Cree LED, so you know there will be some tint shift. It doesn’t look great on a plain white wall, but in real-world usage the beam looks fine







UPDATE 2019-08-22
The lake trip is done and I was able to give the Sofirn SD05 some underwater time. One day while fishing, I tied the SD05 to a string and sunk it to 25 feet of water and left it there for about 5 hours. Then I took it back to land and let my children play with it in the 4 foot pool. There was no sign of water ingress, no fogging, nothing. It worked flawlessly.

This pic is back at shore, immediately following it’s time at 25 feet. Sorry that I don’t have a proper underwater camera - I had to stick my Pixel 3 inside a ziplock bag and submerge it to try and capture some underwater shots… which doesn’t work out all that well.




And here’s a couple head shots after breaking through the blue threadlocker:

First: Where are the fishes? Did they swim away and hide because of the big, bad, bright light? :cowboy_hat_face:

Second: I definitely want to see pictures of this flashlight at the bottom of the lake! It might reveal some things you didn’t know were there! :nerd_face:

Third: Thanks for doing this review. It does look like a nice light. :smiley:

Thanks, Steve. Actually, when doing this review I got so hungry that I just ate them.

Kidding - they’re hiding in the lower-right of that last pic… well away from the business end of that bad boy.

Received my SD05 last week, it is my first light with an magnetic ring.

Is it normal that the ring is relatively loose?

It will rattle when i shake the light.

Its a nice light, i am just curios if this is normal

This is my first magnetic-ring light as well. I’d say mine is loose, but I don’t remember it rattling. I don’t have it with me at the moment to double check though.

I can confirm that the magnet control ring is a bit loose but I don’t get any rattling noise. I assume it’s normal. There are some things I would like to see improved but so far the SD05 is definitely a keeper.

  • 4th mode with a real low level (< 10 lm)
  • CCT in 4.000K - 5.000K
  • ATR without time-triggered stepdown
  • ATR with manually adjustable (higher) threshold for the stepdown (default 50°C)
  • Knurling on the battery tube for better tactile handling

If you need the manual, please check my link below:

Link

It’s a wonderful little light, I need to thank Lightbringer for recommending it.

This is just a waste of a good light. There really should not have any timer stepdown on an ATR. It defeats the whole thing.
Be it in a water environment or in a freezing rainstorm, the light is used for its intended purpose - to throw some illumination in a low visibility context. After some 3 minutes it drops! The ambient temp could transfer that excess heat, but some overprotective “engineer” added a failsafe.

I wonder if you rotated to medium then back to high would reset the timer?

I initially ordered a SD03 (XML2 - 900lm) as didn’t have this timed throttling. Sofirn informed me this was no longer produced. So I took the dive (pun) with the SD05. Made me an irresistible offer. This was yesterday - takes some 3 to 4 weeks to get into my hands.
I think they may be having issues in moving this model. May not appeal to the savvy diver or outdoorsman.

As for the CCT, Sofirn never mentions any values. There is a video of the warmer colors (reds, yellows, orange) being absorbed by water - up to 45 meters. So if you plan on throwing some light 150 feet, a cooler CCT would be better. However, in atmospheric conditions, a warmer neutral light is more popular.

Knurling may not be too comfortable in water laden hands. But I agree a subtle grip surface would be a plus.

You’re very welcome! The SD02/WK20, the SD05, the WK30… I hit the trifecta of kick-ass lights, too. :laughing:

Agreed on the timed stepdown (no need for it with ATR), but I do like the smooth unknurled stepped-hourglass shape of these lights (all 3 mentioned above). They shouldn’t slide out of the hand too easily with any decent grip. And a lanyard is a must for underwater!

Tried mine out the other day. Got to 16’ with it and it performed fine. Was in too high turbidity water for it to be useful, so can’t really comment on beam or runtimes. I did notice the magnetic ring slid to ‘on’ once when I wasn’t using it. Not too happy about that. Overall, it functions, which is half the battle with a dive light.

I like it better than my thorfire S1 so far. The S1 is too bulky, and the ring is way too loose, always worried it’s going to turn on by itself. It also got sand under the magnetic ring so now it feels gritty when you move it. Beam isn’t all that great for me either. I need flood, and it’s too much of a thrower.

If this light had variable output with a low around 1 lumen (or less) and the existing high of about 2500, with the magnetic ring control, I’d be all over it.

SD03 is still available at Fasttech.

And now I almost regret my impulsiveness…
Hadn’t given any thought to check them. Sofirn store owed me on my previous order (3 holsters at full price - couldn’t get their messaging to work on my end). Thru email I worked out a discount on this order. About same price.

Much that I like Sofirn for their continuous upgrading of their lights, the Ali Store leaves a lot to be desired in functionality. The messaging is cut to 40 characters, there is no invoice (for printing) and Sofirn can’t (or won’t) cancel an order to replace with a supercede. This last exchange makes for a jumble of my purchase(s) with no mention of the SD05. Have to trust Cissy (or Crow) in delivering the goods.
Fasttech on the other hand cancelled a discontinued item, offered a credit refund or a discounted price for a replacement. They often don’t have the merchandise on hand (hence the “ships in x days”) and rely on the manufacturer. So they may offer an item without knowledge of availability.

I seems so, but then again ATR kicks in very fast, so you won’t be able to reach another 3 minutes of full output...at least not in usual atmospheric conditions.

I was able to test ATR on my sample. It seems ATR kicks in at 50°C already and not at 55°C. Even another reset would not take it beyond 53°C. I was able to reproduce the stepdown behavior several times. This could either be a wrong temperature calibration from factory or the manual is wrong about those 55°C. My thermal imaging camera has an accuracy of +/- 1°C.

Bottom line: The SD05 is the right flashlight for people who don’t want to burn their hands. :-D

After 3min...

After another 10min...

After resetting and restarting High once again...

So another reset can be done. Blizzard / freezing rain would dissipate heat before ATR kicks in. An annoyance to reset but will have to live with that. Changing the driver on a rotary switch and everything glued together makes for an un-moddable light.

If I had the skill and knowledge to re-program the MCU, many lights would lose their timed behavior.

Can you get that magnetic ring off and check the components? In a number of dive lights using magnet switches I’ve found low grade steel bearing and springs used. OK for land. Goes to rust and garbage in short order when used in saltwater.

I have this one and I’m proud! I’m thinking to get a 2nd one :slight_smile:

Nice review gchart! I look forward to hearing about your lake trip.

Could you post some photos of the disassembled light to see the way the LED is mounted? Thanks!

UPDATE
The lake trip is done and I was able to give the Sofirn SD05 some underwater time. One day while fishing, I tied the SD05 to a string and sunk it to 25 feet of water and left it there for about 5 hours. Then I took it back to land and let my children play with it in the 4 foot pool. There was no sign of water ingress, no fogging, nothing. It worked flawlessly.

This pic is back at shore, immediately following it’s time at 25 feet. Sorry that I don’t have a proper underwater camera - I had to stick my Pixel 3 inside a ziplock bag and submerge it to try and capture some underwater shots… which doesn’t work out all that well.



Sure! Here’s a couple head shots: