Lumintop BLF GT

BLF GT review

Table of contents

  1. Intro
  2. Beamshots
  3. Conclusion
  4. Where to buy

Introduction BLF-GT

The Lumintop BLF GT is a next-generation super thrower, commonly called the GigaThrower. It was developed by members of BudgetLightForum, in collaboration with the renowned flashlight manufacturer, Lumintop. The project started in 2016, and updates were slowly rolled out the following year.

In December 2017, the 2nd iteration of the light was developed and approved by the BLF team to start mass production. It was good to receiving honors as the farthest-throwing LED light of the year!

The pictures probably don’t do justice to its actual size. Seeing this light in person is what makes it so exceptional…. Let’s take a look at what this throw monster has to offer.

Lumintop BLF GT specifications

Brand/modelLumintop BLF GT
LEDCree XHP35 Hi
Lumens2,000 lm
Beam intensity1,00,000 cd
Battery config.4/8*18650
ModesMulti (NarsilM)
BlinkiesMulti (NarsilM)

Handling of the light

Holding the BLF GT, you first notice that it definitely isn’t one of the easiest lights to handle one-handed. If you have small hands, this light might not be suitable for one-handed operation.

I imagine that for most buyers, the GT won’t be used too much for practical work, since it’s not a Tactical Flashlight nor an EDC light. It’s quite fun playing around with it, but finding its uses is difficult for us enthusiasts. If you are only using 4x 18650s (it works on 4 and 8 cells) you should put the carrier with the batteries towards the backside of the light. This helps with balancing. Otherwise, the center of gravity is towards the head, and becomes front-heavy.

Lining up! Unfortunately, I noticed that the holes for attaching a carry strap are not lined up straight, nor are the flat parts on the body matching the side switch. If you attach the strap, the button is actually on the bottom of the flashlight, not on the top. See the pictures below. The tailcap has the other attachment point, which can be moved around. It can be seen as loose, but it’s actually a neat feature for moving the tailcap around. The tube is quite thick, but this is to be expected for an 8*18650 battery tube that has to include multiple carriers.

The body diameter is also a little on the wide side, but this is to be expected for a 4*18650 battery tube, including a battery carrier!

Tripod hole

I also do photography work, and I own a Manfrotto tripod with a 029 head. Surprisingly, the head takes the Manfrotto hexagonal quick-release plate. And guess what? The thread doesn’t fit correctly. Looking at the pictures linked above, you can see the ring they put in the tripod hole, but the head is too close to the hole to attach to the quick-release plate. Of course, you can add an adapter, but not everybody owns one.

Flashlight Knurling

The GT body possesses quality knurling without any sharp edges. That being said, it is slippery. Take a look at the picture to see the knurling up close.

The anodizing has been well applied, but I am not completely satisfied with it. This kind of glossy anodizing tends to accumulate fingerprints and dirt, which I do not like. As seen in the picture, the printing is done well. There is nothing to complain about here, but it isn’t very exclusive either.
Threads came completely dry. This can be a con for some people. For me, this isn’t really a problem, as it allows me to clean the threads and put new lubricant on them. The O-ring is lubed. The threads are a bit loose side when screwing onto the head.

LED, Lens, bezel and reflector

The reflector is made of plated aluminum and is smooth—but not smooth as butter! At least mine has some noticeable machining rings.

  • Diameter head inside 118mm  (4.6″)
  • Diameter outside head: 135 mm (5.3″)

The bezel is just plain anodized aluminum, not stainless steel, unfortunately. This means that a drop on the concrete can damage the bezel and make it impossible to take it off. I couldn’t even open the head.

led of the blf gt

Battery carrier:

The battery carrier has a metal construction. You have to use button-top batteries! But they can be very snug. I used protected NCR18650B Panasonic batteries, and they fit but tight.

Unprotected, flat-top batteries don’t fit in the original carrier! The carrier has an extra layer of protection for reverse polarity insertion in the form of a plastic disc. Be careful still.

This plastic “washer” can be removed, so it is possible to use Flat-Top batteries, as I have tried. See the pictures. But with unprotected flat-top batteries, they are almost too short for the carrier! They work, but the light can turn off with hard bumping!

To get the light working, you need to use 2 battery carriers. However, you don’t need to run all 8 batteries, as the light will run on either 4 or 8 batteries. If using 4 batteries, running them in the carrier towards the tailcap and leaving the empty carrier towards the head will give you a better-balanced light. It uses dual gold-plated phosphor bronze springs, meaning resistance isn’t an issue, even with only 4x cells.

How do you modify the battery carrier to fit flat tops?

WARNING: WARNING: This will void your warranty if something goes wrong! Only do at your own risk! Removing this “protection” will open the possibility of reverse battery insertion and can damage the light’s springs, shorten the batteries’ life, or even kill them if the springs don’t melt.

Dimensions and weight of the Lumintop BLF-GT:

  • Length: 315 mm (14.4″)
  • Diameter head: 135 mm (5.3″)
  • Diameter battery tube: 56mm (2.2″)
  • Weight empty 1800 grams (3.9 pounds)

Flashlight comparison

From left to right: Acebeam K75, Astrolux MF04, Lumintop BLF GT and Lumintop BLF GT90.

size comparison long range flashlights 3

User Interface

The BLF-GT uses the Narsil driver firmware developed by BLF member Tom E.

Download here:  BLF GT manual

Default UI: ramping

This UI has smooth ramping between 0% and 80%, while still be able to switch to the 100% Turbo mode with a double click as mentioned below:

  • Turn on: single-click, last mode memory (last use level of output)
  • Ramping output level: press and hold
  • Reverse ramping: While ramping in one direction, release button briefly and press + hold again
  • Instant TURBO: double-click
  • Turn off: single-click
  • Ultra-Low mode: from OFF: press the button and release as soon as the GT turns on.
  • Strobe: 1. double-click for TURBO, and 2. double-click again
    (Use single clicks to cycle forward through the different types of strobes, but you have to be quick: If resting on a strobe longer than 1.2 seconds, it locks in, and the next single click is OFF. Press+hold at any time to cycle backward through the strobes.)
  • Battery status: triple-click (4 blinks, with a short pause, and then 1 blink would indicate 4.1V average per cell, as an example)
  • Electronic lock-out: 4 clicks, and to re-enable again 4 clicks.
  • Momentary ON mode: five clicks (loosen and re-tighten the tail-cap to return to normal operation)
  • Factory reset: triple-click (battery status mode), then double-click (driver temperature mode), double-click again (firmware version mode), then press&hold for about 2 s. Four blinks confirm a successful reset.

Alternative UI: Mode-sets

The GT is by default in the Smooth Ramping mode. However, it can also be operated using more conventional modes. (See the next section for details on how to set UI options.)
Using the MODE-SET UI the output does not ramp, it steps from one mode to the next using single-clicks, just like with a usual flashlight.

  • Turn on: single-click
  • Next mode: single-click (within 1.2 sec)
  • Previous mode: press + hold
  • Last mode [100%]: from off: press+hold
  • Turn off: single-click (after 1.2 sec)
  • Strobes: press+hold. Single clicks to cycle through all Strobe modes. Press+hold to cycle backwards through the strobe modes.
  • Battery status: from OFF: single-click followed by press+hold. How to read the Voltage: if there are 4 blinks, a short pause, then another 1 blink, it would indicate 4.1 V average per cell.)
  • Electronic lock-out: from OFF: double-click followed by press+hold, same to re-enable again.
  • Factory reset: from OFF, single-click followed by a press+hold (battery status mode), then double-click (driver temperature mode), double-click again (firmware version mode), then press+hold for about 2 seconds. 4 blinks confirm a successful reset.

The backlight of the switch: The backlight of the switch is turned on by default when the flashlight is turned off. If you don’t want to use this backlight you can simply turn off that feature by quickly switching the power on and off. Unfortunately, it will only stay off till the next use.
The parasitic drain is ~250 μA with the light turned on, and ~150 μA without.
Unfortunately, the button they used is BLACK, so the backlighting on the switch is really hard to see! One can only wonder why they chose black..

Momentary on:

The momentary on only works when you tap 5 times while in the ramping mode. It is not accessible while being in any “mode sets”. It seems like you can only get out of this mode when doing a complete turn-off, like turning the battery carrier.


  • Nope… nothing to worry about.

Current Draw

Max output in Ramping mode: 2A 

Turbo mode: 2.5A

Farthest throwing production LED flashlight with reflector.

Candela and throw were measured at 10 meters / 32.8ft:

  • 830,000 cd (1822 meters / 1.132 miles) in Turbo (4 batteries Panasonic NCR18650B 3400mAh)
  • 940,000 cd (1939 meters / 1.2 miles) in Turbo (8 batteries Panasonic NCR18650B 3400mAh)

I can’t seem to get mine past 1Mcd.. I measured at 20 meters and still couldn’t touch the 1 Mcd mark. It might be my poor and cheap lux meter. Who knows.

Being a thrower, it does not enter the brightest flashlight list by any means, but one of the best lights overall.

Beam shots:

Lumintop BLF GT vs Lumintop BLF GT90.


For more discussion about this flashlight take a look here:

Conclusion and verdict

Positive points:

  • Farthest throwing stock LED flashlight in the world as of 2018 Q2
  • One of the few flashlights in production ever fully conceived and designed by flashlight enthusiasts rather than a manufacturer
  • UI is easy to use, and at the same time comprehensive enough for power users with the hidden UI.
  • Extremely long battery life

Negative points:

  • Size (this is to be expected)
  • Programmable UI can be difficult to understand.
  • Alignment of attachment carry strap
  • Doesn’t fit directly onto some tripods
  • The backlit switch uses a black switch, with most of the light blocked off
  • Including a better box or a carrying case would have been great.

Rating: Excellent

This is an extremely far-throwing flashlight! It can reach further than your eyes can see. It’s bigger than you probably like to use daily, but you could still get a carrying strap if needed. I give it 5 stars because it does everything that it needs to do.

Lumintop BLF GT for sale

It’s discontinued. Look at the Lumintop BLF GT90 instead, or the Wuben A1.