Sofirn LT1s Lantern Review (21700, Tint Shifting, Red, USB-C)

Today I am looking at the Sofirn LT1s, where the s stands for Small or Short. If you have followed my reviews you know I really enjoyed the BLF/Sofirn LT1. While the LT1s takes some design cues and even a few parts from it’s larger brother, the two are really different lanterns on the inside. The LT1s runs on a single 21700 battery, offers red mode, tint shift in white, aimable beam, and a different UI. Thanks to Sofirn for sending this to me now let’s get to it.

 

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Pickup the Sofirn LT1S Lantern at https://bit.ly/LQLT1S and use code BJ5B11QN to save 15%. (Valid till 4/28/2022)

The LT1S is also available on Amazon https://amzn.to/3Nz5xL5  use code 20WQ2PHC to save 20%. (Valid till 4/28/2022)

Here is the case I featured in the review, it fits but isn’t a perfect fit. https://amzn.to/3LlK1aO

 

Packaging & Accessories

Not much to write about here, Sofrin like usually has very basic packaging. Inside the light is wrapped in bubble wrap to protect it during shipping. Accessories with the LT1s include a 5000mAh battery that’s preinstalled, 2X extra orings, USB-A to C charging cable and the manual. 

 

Construction & Design

The LT1s takes many design ques from the LT1 on the top half at least. Starting at the top you have the hanger which is identical. You then have the main textured button that has a satisfying click to it, your 4 amber power level indicator LED’s, and the USB-C charge point. It’s a little odd to see the charge port be on top for moisture reasons, but the LT1s did survive a trip in the shower with me without issue. 

Below this is the same style of diffuser as the LT1 a white diffused hard plastic. The LT1s are all on the top of the light facing down, and in the white modes you can turn off half to better steer the beam to the side where you want the light, I will talk more about this later on. 

At the bottom you have the large tailcap. It doesn’t have much in terms of grip on it and it could be challenging to use with gloves or when wet. Threads here are ACME cut and sufficient. The tail cap has a large beefy spring to make contact with the inner battery tube, completing the circuit on the inside of the light. The large spring also allows you to run the light on an 18650 without issue other then some side to side rattle if shaken, even though it’s not officially rated for it. The head side also has a smaller spring. 

There is very minimal branding on the light, Only the Sofrin logo, model number and battery direction indicator on the front, serial number on the back and your typical CE, ROHS, and Recycling marks on the bottom. 

 

Thanks to Reddit user /u/DerMaxPower for allowing me the use of his deconstruction photos. You can see there are only emitters mounted on the top facing down, the center battery tube is aluminum which helps with heat dissipation. It’s a simple design but very functions.

Overall it’s a solid feeling lantern. The aluminum on top and bottom feel much better then the cheaper feeling plastic the competition uses. I suspect it makes it a good amount more durable as well. 

 

Mounting

Your primary method of mounting this light will be the wire bail at the top. This folds in either direction and can be removed if you wish. The LT1s ditches the ¼ 20 threaded receiving holes that the LT1 had and the tailcap is not magnetic. 

 

I spent some time on Amazon looking for a speaker case that would fit the LT1S and ordered a few things. Here is a link to the best one I could find at the time. https://amzn.to/3LlK1aO It’s not a perfect fit and a little to narrow but it does zip and leaves a little room for a charging cable and small charger if you wish.

 

Size & Weight

I measured the length at 97mm at the maximum height. Diameter at the top was 68mm, diameter at the bottom was 59.5mm. Weight with the battery is 338.9g. The light is IPX8 water rated and I confirmed this by putting it in the shower with me one day. I didn’t completely submerge it though. Here are some comparison photos with the LT1 and Olight O’Lantern. 

 

Emitters and Beam

The LT1s uses a lot of LED’s, 40 in total to be exact. 18x 2700k in the CSP 1919 package, 18x 6500k in the CSP 1919 package, and 4x Lattice Power Red LED’s. Sofrin doens’t give an exact model, but there is speculation they might be Luxeon brand due to the high CRI. My unscientific Opple meter measured the warm tint as 2585 CCT with a 97Ra, and cool white as 5732 CCT with a 100 Ra. I think these numbers should be taken with a large grain of salt for the Ra value. They are clearly high CRI probably above 90 but I wouldn’t read any more into it. It’s interesting that the cool white number didn’t quite hit the 6500k claim. In moonlight mode I did notice some PWM visible to the eye but this largely goes away in higher outputs at least to my eye. However it can be detected via my Opple meter or scope. 

The LED’s are mounted on the top of the light and well diffused to create a nice light pattern. The light does have the feature of being able to shut off one side while in white mode, to direct the beam to a 180 field of view rather than the full 360. This works pretty well,  I think it’s probably more useful to maybe not shine in your eyes so much if you have it out on a patio table or in a tent etc. It’s a nice idea but only works in the white modes.

 

Official Outputs

 

Runtime & Heat

I did lots of runtime tests here with all the different modes, and a few extra with the light powered by an 18650, and by a 10k powerbank. I will try to let the graphs do most of the talking here.

 

Since the light is capable of 4 tints I ran some tests multiple times and did comparisons. Here is the runtime test for the maximum warm output with the 5000mAh battery, As you can see the light can sustain nearly 100 relative output for 25 minutes before stepping down, Total runtime ends up being 3:09:00, with max temps reaching 42C. I ran the same test comparing Warm, Cool, and Neutral Outputs, and results are similar. Cool white had the least runtime, but only by 10 minutes, then warm. The surprise was Neutral white, it had the longers runtime by about an hour. More LED’s but less bright I assume. It resulted in a more linear output and ran out to 4:03:00. 

I also tested the runtime of running one side of the emitters in the warm mode at full output vs both sides. As expected running half of the LED’s result in a more stable output initially and for longer. It resulted in a substantial increase in total output but over half of this was at about 5% relative output so very dim. 

The red runtime shows the light isn’t able to sustain it’s high output for nearly as long as it’s white output in it’s highest mode before step down but the decline is slow. It has about 2:30:00 of it’s main output but continued to run at 5% for a considerable amount of time for a total of 5:30:00. 

Since an 18650 battery fits and makes contact I threw in a 3000mAh VTC6 and it’s output shape was identical to the 5000mAh 21700  but just shorter Total runtime was 1:43:00 vs 3:06:00. 

The lantern will also run directly off USB power (Without a tail cap or battery too when plugged into USB), although in lesser output. I ran it off a 10k powerbank and it ran for 12:20:00 which is impressive.

  • LVP – 2.738v
  • Full – 4.102v
  • Drain measured at 150-198uA

 

UI

Unlike the original LT1 the LT1s is using a UI Sofirn developed instead of Andruil. This is kind of disappointing because Anduril works so well on the LT1 and the special blinking modes are great there. That said my guess is Sofrin wanted a simpler UI, especially for switching between LED colors. The Sofirn UI here works well in my experience and the list below should serve as a simple guide of what you can do.

 

From On

  • 4 clicks to switch between ramping or stepped mode
  • 3 clicks to go between red and white modes
  • 2 clicks (Double click) to operate as a directional light and move between either side or full on just repeat
  • Double click when in red mode to activate SOS
  • 1 click and hold to change the tint of the light
  • 1 Click hold to switch between modes or ramp to adjust brightness

 

From Off

  • Long press to turn on to moon light mode. 

 

There is no ramping in Red mode and when you shut the light off in red mode, memory won’t return you to red. 

 

Recharging

The lantern recharges via a USB-C port on the top thats well sealed with a silicone cover. It is USB-C PD compatible, and it works as a powerbank to charge your smartphone or other device. My Samsung Smartphone reports it as charging via “Fast Charge” when plugged in. I didn’t do much testing here other then to verify it works. Here is the charging graph of the included 5000mAh battery from LVP at 2.738V to full at 4.1V. This took just at 3 hours and 18 minutes. Max charging speed I saw during this was 1.8A. The manual says it charges up to  3A max charging speed but I didn’t see anything like this. It may possibly need to trigger QuickCharge but it doesn’t seem to use the normal USB-C protocol for this. 

The light will run while charging although this significantly slows down charging speed. I ran the light at max output and started charging via a 65W USB-C power source, and at the end of 4 hours it was showing only one LED solid so between 25-50% power. I let the light go for 24 hours and it never fully completed charging but got to between 75-100%.

 

Final Thoughts

Lanterns are one of those things you can probably do without if you have a good flashlight but once you have one you immediately notice the value of having a light designed with a specific task in mind. The LT1s is the smaller, more stable, easy to use version of the LT1. 

Reading over the comments at BLF on the LT1s there are a few that are a little unhappy about the similarities in design to the BLF LT1 that Sofirn produces. That said I think most have concluded that the two are different enough not to ruffle too many feathers, and I agree. 

 

I like the more simple UI here for the most part, it’s going to be better for most people who are not used to Anduril nor want to take the time to learn it. The addition of red here is great for those who want to preserve night vision but even in low, I would say it’s almost too bright and on high it’s really bright. I like the ability to shut off half the white emitters to steer the beam, it’s nice for keeping the light out of your eyes if it’s sitting on a table or something. I am using this lantern quite a bit in the shower even to have something a little more soothing, and with less blue light.  

This is an easy recommendation for me, the pro’s easily outweigh the small cons. Sofirn has provided a 15% discount which I will have in the description/comments below the video. I will also have a link to the case I found that almost fits but isn’t quite thick enough for my liking. 

 

Pickup the Sofirn LT1S Lantern at https://bit.ly/LQLT1S and use code BJ5B11QN to save 15%. (Valid till 4/28/2022)

The LT1S is also available on Amazon https://amzn.to/3Nz5xL5  use code 20WQ2PHC to save 20%. (Valid till 4/28/2022)

Here is the case I featured in the review, it fits but isn’t a perfect fit. https://amzn.to/3LlK1aO