Contents

• Pricing & Availability
• What comes in the box?
• Design & Construction
• Size & Measurements
• User Interface
• Emitter & Beam
• Performance
• Carry & Ergonomics
• Batteries & Charging
• Conclusion

Pricing & Availability

Sofirn sent me this light in exchange for an honest review. Here is the official product page and Amazon page where you can see current pricing. Sofirn also gave me a limited-time 10% off Amazon link and a 10% off code (10SQI2NG) to share.

What comes in the box?

SF16 comes in Sofirn’s standard retail box with just a sticker to tell you what’s inside. The contents are held in place with a vacuum-formed insert.

• The light itself
• Battery (inside the light)
• User manual
• USB A-to-C charging cable
• Wrist lanyard
• Spare O-rings

Design & Construction

Besides the black lens and yellow warning sticker, SF16 looks like a generic and unassuming 18650 flashlight with a tailswitch. It’s a tube with a lens on one end and a switch on the other. Not designing a fancy host just for this UV LED helps decrease costs.

Build quality is good. It doesn’t wow me but I can’t find anything to complain about.

Size & Measurements

Skilhunt MiX-7 | Skilhunt H300 144A | Sofirn SF16 | Olight Warrior 3S | Mini Maglite

Measurement	Measured (mm)
Bezel Diameter	25.0
Maximum Head Diameter	25.9
Length	122.9
Switch Diameter	14.0
Switch Proudness	-0.8-3.8
Body Tube Diameter	22.8
Pocket Clip Slot Width	4.3
Pocket Clip Slot Diameter	21.0
Tailcap Diameter	24.9
Tailcap Length	31.0
Driver Diameter	~20-21
Included Battery Length	66.8

Weight with included battery: 109g

Switch & User Interface

SF16 uses a reverse clicky mechanical tailswitch. Fully clicking the switch turns it on and off. Half-pressing or tapping the switch while the light is on will cycle the mode (low-med-high). It has mode memory and will turn back on in whatever mode was last used. There’s no momentary-on function.

A simple UI like this is ideal for a UV light, but I don’t think it needs multiple modes. The brightest mode lasts for hours and doesn’t thermal throttle. One mode and a forward clicky switch for momentary activation would have been even better.

Emitter & Beam

The emitter is an SST08-UV. It sits behind a ZWB2 filter instead of a clear lens. That’s not common on UV lights but it’s hugely beneficial. It blocks all the visible blue light from the UV LED and only lets UV light through. That makes fluorescent objects appear to glow brighter and allows you to see faintly glowing objects that would normally be washed out by the visible light. Below is an example of a different UV light with and without a ZWB2 filter installed.

I was unable to unscrew the bezel even with super grippy gloves, so I didn’t get any photos of the LED. I assume there’s a reflector under there too based on the beam profile and the fact that plastic optics block UV.

The beam is narrower than I’m used to on a UV light. That makes it good for reaching out further or punching through some ambient light, but not as good for scanning a room. There’s still enough spill that room-scanning is doable with white lights off though.

Below is an example of what you can do with this UV light. While looking in my pantry for objects that glow, I noticed these empty water cans completely change color under UV. Neat!

Performance

This light doesn’t get hot enough to thermal throttle so there’s no need for thermal regulation. That also means we can use the runtime graph to check the brightness regulation as well.

Driver: Sofirn told me this light has a FET driver. FET drivers are cheap and unregulated so they keep the cost down but also may not perform well as the battery drains. That’s particularly true for UV LEDs which are notoriously difficult to drive.

Performance exceeded my expectations. I expected bright output briefly and then for brightness to fall like a rock. It stays quite bright for several hours and then hits a plateau, which is still usable. Very impressive for a FET driver with a UV LED.

LVP (Low Voltage Protection): I’m not sure if this driver has LVP built-in or not. I ended my runtime test before the light shut off because it had been going so long. It comes with an unprotected battery and all other Sofirn models I’ve tested have had LVP so I suspect this one does too.

PWM: No PWM is visible to my eyes nor audible to my ears.

Parasitic Drain: There is no parasitic drain because this light uses a mechanical switch.

Carry & Ergonomics

SF16’s ergonomics are fine. It’s comfortable and sized well in a reverse grip or cigar grip. A forward grip works too, but you can’t access the button.

The clip is basic but it gets the job done. It’s possible to tail stand the light thanks to the fins on the tailcap, though I’m not sure when you’d need to do that.

Batteries & Charging

Battery: A 3000mah, unprotected, button-top, 18650 cell is required and included. There’s plenty of room so protected cells should also work just fine. You might even be able to steal the 18350 body tube from another Sofirn model and install it on SF16, but I’m not certain.

Charging is facilitated by a USB-C port on the side of the head. It’s covered by a rubber flap when not in use. C-to-C charging works and there is no powerbank function. The light cannot be used while charging. Cleverly, Sofirn put diodes in the tailcap so the light can charge without the switch being pressed.

Battery Indicator: Below the charging port is an LED that serves as a charging and battery status indicator. When plugged in, red means charging, and green means fully charged. It also activates for a few seconds when the flashlight is activated. In that case, constant green means 75-100% charge. Blinking green means 50-75% charge. Constant red means 25-50% charge. Blinking red means 0-25% charge. I like that system and I think it’s a bit more intuitive than the blue and red colors I’ve seen in a lot of battery indicators recently.

Conclusion

This light is special because it’s the only UV light I can find that comes with a battery, charging solution, ZWB2 filter, and is accessible (Available on Amazon in the US for a reasonable price). There are plenty of other accessible UV lights, but they don’t have a ZWB2 filter, and/or they’re expensive. There are plenty of other affordable UV lights, even some with a ZWB2 filter, but they aren’t easily accessible. I haven’t had a go-to UV light recommendation before. Now I do.

Thanks to Sofirn for sending me this light for review!