[Review] Sofirn SD05 Diving 21700 Flashlight

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:

Awesome! You Are The (aqua)MAN!

With the phone, I've double bagged mine at the beach and swam but you never know if it's going to really keep it dry. However, I think you're talking about taking shots through the plastic bag which doesn't yield good results either.

Good review, thanks :slight_smile:

But are there real plants in fish tank?

On TLF, Adelina reported that the magnetic ring will undergo a revision to have less play.

I wonder if there’s a chance for a couple of other improvements:

  • color temperature 5000K
  • no time-based stepdown
  • orange or yellow anodization
  • firefly mode (i.e., firefly - off - low - mid -high) for use on land

Shouldn’t cause to much work or money to do it right :slight_smile: .

Regarding stepdowns and Sofirn's ATR this is what I have suggested to Sofirn in general...

  • Please remove timer-triggered stepdowns from future drivers/flashlights. There is hardly any reason to have
    both thermal and timed stepdowns at the same time. Customers on TLF and BLF would greatly appreciate to
    have thermal regulation only.
  • Please allow a user defined choice of ATR thresholds (e.g. 45°C, 55°C, 65°C) just like HaikeLite did with their
    SC26…
    Thermal protection setting can be accessed by 10 clicks:

The light flashes once => turn it off to select 50 degree step-down temperature
The light flashes twice => turn it off to select 60 degree step-down temperature
The light flashed 3 times => turn it off to select 70 degree step-down temperature

Important: Please set 50°C to default by factory to make sure that customer complaints about too much heat are as
low as possible. Barry recently talked about it on TLF. With 50°C as default this problem should be solved. More
experienced flashlight users or people who want to unleash the full potential can raise the threshold to 60°C or 70°C.
There is no disadvantage with this new feature but Sofirn will make their flashlights even more powerful and more
successful.

Work and production cost are often not the issue, convincing a manufacturer that a change is an improvement and profitable is the big hurdle. And Sofirn, and also Simon from Convoy Flashlights, get loads of suggestions coming from BLF-members, and that is a mixture of good ideas and mediocre to bad ideas, so they have to sift through the lot as well to find the good ones that are an improvement and/or will increase the profit.

I see. Someone could still make this a BLF edition group-buy thing. I assume we all see the reasonable changes here, or am I completely wrong?

No, you are right, some changes seem 100% a good idea. But it so appears that what we flashoholics as a group see as reasonable changes is not just as obvious for the chinese manufacturers, 1) because they sometimes have less insight in how a flashlight should be, 2) because they know things about manufacturing that we do not know, and 3) because their audience and profit comes from a wider group than just flashlight enthousiasts from BLF, and for muggles some changes are rightout a bad idea.

I agree with you Jos. This recognition might be the result we now see with Sofirn's SP36S which basically is a simplified SP36 BLF Andúril edition, coming with a less complex user interface and a more conservative thermal management (2min timer, 55°C ATR). And that is also the reason why I have proposed a thermal regulation to Sofirn that is fair to all sides and addresses both requirements for enthusiasts and apprehensions of muggles. Being more flexible with user-defined thresholds flashoholics will be able to unleash the full power whereas - on default - muggles can safely operate the light with moderate settings.

Ordered a SD05 and put my trusty protected Trustfire 18650 battery in. I really like the form factor, the build and the magnetic ring, but i’ve got a problem:
It does work on low mode and middle mode, but as soon as I turn on high the lamp turns most of the time (not always!) almost immediately off. I have to anscrew the tailcap and screw it back on and then it starts over again.
Is my battery showing it’s age (5 years now), do 18650 not fit properly or is it a problem with the torch?

I’d suspect the battery.

Battery, especially if it’s protected and high-mode just draws too much current. That, or it’s just old and its too-high internal resistance causes too much voltage-sag and the light cuts out under lvp.

Some lights you can get away with laptop-pulls and other rejects, others nope.

There may be a problem with the protected battery. The high current consumption is 5.7 amps. Protection disconnects the battery. I also have SD05 and I measured the current draw.