The easiest way to test for bad PWM is to sit in a full dark place, and turn the light onto the various modes.
Then wave your fingers, or a pencil, white stick, etc. as fast as you can through the beam.
Good PWM or no PWM you’ll see, the stick waving in the beam.
Crappy PWM will show the stick looking like an old time movie, jerky movements, with sharp moments and blur.
If you can see this, usually the PWM is poor enough to be bothersome.
Also videoing the beam shining in a dark room will show – some – PWM. The PWM frequency will interact with the shutter of the camera and the video will show the light pulsing.
Or use a camera, open the shutter for a half second, and swing the light through the frame as fast as you can.
And example. Nitecore TUBE 500Hz PWM.
So you are capturing a light that is flashing on for a brief time 500 times a second.
Looking at the PWM on a scope shows
The light is on for only a very short period during the 1/500 of a second cycle.
A light with slow PWM will show as a series of pulses instead of a steady beam.
You can detect PWM up to around 4K with this method (If you can wave your arm fast enough).
I describe how to measure PWM using a sound card in this thread.
I use a small portable fan, shine the flashlight through it and look at the fan blades.
I'm not sure what's the rpm (revolutions per minute speed) of the small portable fan I'm using, but it's so far able to show "slower PWM" and "faster PWM" by visually looking at the light passing thru (reflecting thru?) the blades.
For instance, I made a simple video.
one uses Biscotti (faster PWM, not so visible to most people in normal situations)
one uses Convoy 5/3-mode group driver (PWM is a bit more visible)
Left side shows the faster PWM on Biscotti, right side shows the slower PWM on the Convoy 5/3-mode driver
It's not like my other Sofirn lights in any way (Q8, SP33, SP32A, SP10S, SP10A, C01S) hard to explain, it just not a Sofirn light, Funtastic is right.
The beam shots in the album are not what I wanted from a zoom light, I was approx 6ft from wall when photos taken, camera was in manual mode so no auto exposure correction going on.
When in wide there is a halo, zoom and you just fill the halo, not really a zoom if you ask me, the area filled is about the same as my Convoy S2+
There is no lens just a frosted dome over the led, the USB charging port cover feels like it's going to rip off first time it get shoved in my pocket, the red light is the charging light, I was hoping it would slowly fill up as battery charges but after 2 hours it's still the same, I'll report back when fully charged.
Thanks for taking the bullet for me, I was about to add this light to my Sofirn order to hit the $100 mark (10% off at Sofirn.com). I decided I need another IF25a, lantern and C8G… just a few bucks over $100– so NOW it’s $91!
I would rather call it S11B, because it is not made by sofirn. S11B and D25/D25S are made by the same factory. If you have any D25/D25S headlamp, you know the quality.
Furthermore, I am upgrading S11B to be S11C: LH351D LED, simple UI:
click to turn on/off, press and hold to choose brightness from Low-Med-High. Press and hold to Moonlight from off.
Triple clicks to Strobe from off; 4 clicks to lock-out from off.
I really like the sound of that UI. I’d like it if it also had double-click for turbo, the same as the Olight Baton UI.
Replacing the strobe with a battery check would make it perfect, but I understand that may not be possible and some people want a strobe mode.
I’d be happy to have the Olight Baton UI in pretty much any of Sofirn’s lights that aren’t running Anduril. In fact I’ve been meaning to suggest it for the SP10.
Update: I ordered one today and it looks to be just what I was after- a good, VERY cheap zoomy! It’s cool to get good referrals to BUDGET lights like this one. I seem to get stuck on the same stuff (Sofirn for one… and good stuff it is), but it’s nice to get out of the box an find deals in the corners like this one. I am not expecting anything but a $12 light here BTW. But it’s the $12 lights that are decent that “turn me on” for sure!
I’d like to see MORE posts like yours where we all can share the decent “el cheapo’s” out there. One never knows until someone takes a chance and posts it— thanks man!
I like what I see in the first picture, a proper and more or less flat emitter retaining ring. The emitter should sit very close to the lens when in flood, doesn't it HenrysCat? I wonder what driver size does it uses.
Bad points, imho, are single hole at the tail for lanyard, and only ∅42mm head for such a long flashlight.
But hey! It's nice to see they are listing the correct capacity and weight for the red UltraTurd batteries. :-D
Yes the LED is right under the lens in wide, below I'm about 2ft from wall, if I step back to about 6-7ft it covers a good 3-4ft of floor and ceiling, so it's very wide.
Here zoomed in fully again about 2ft from wall,
And corrected, this is what you actually see, the pattern of the led itself.