Lumintop BLF GT90

Lumintop BLF GT90 flashlight review: Luminus SBT90.2 LED  7,000 LUMENS

Introduction:

Say what? Another BLF GT flashlight? Okay.. this must be the 5th? Not sure, but the Lumintop GT lineup has been very, very popular amongst flashaholics and outdoor enthusiasts. It all began a few years ago with the Lumintop BLF GT. The one we reviewed. Now, 2 years later, they added yet another one to their lineup, and this time with a Luminus SBT90-2 LED. This bad boy can shine very far and at the same time put out a lot of lumens. Just with every new light that throws the farthest or is the brightest, I can't wait to review it. Let's dive in.

What you'll get:

Uhmmm Lumintop? Did you actually think through this? Or did I get a monday morning sample? The only things inside the box were the flashlight and 2 o-rings.... No lanyard, no pocket clip.. LOL and not even a Manual.

Brand / ModelLumintop BLF GT90
LEDLuminus SBT90.2
Lumens7000
Beam intensity1.875Mcd
Battery config.8*18650
MaterialAluminum
ModesRamping
BlinkiesN/A
ReflectorSmooth
WaterproofIP65
Review dateJanuary 2020

Handling of the light


Lucy said she found a flashlight that looked like a torch... I guess she was talking about the BLF GT90? But I can see what she is getting at. This thing is huge. Yes, as large as the BLF GT. I mean, holding this bad boy is like exercising. The weight is over 2Kg (76oz). Your wrists will soon become like Popeye's. The head is heavier than the flashlight body, so you can definitely feel that in your arms after a while.

Therefore, I don't really understand why my package doesn't include a carry handle, lanyard, shoulder strap or anything. It has a tripod mount and a screw that you can use to attach a strap or something.

The GT90 uses a side switch with a dim green light behind the rubber boot. It's an electronic switch, so you can either press it once (click) or press and hold. Both have different functions. The position is fine. They haven't really upgraded anything from the older BLF GT.

If you want to use it as a candle, who doesn't, then you can tail-stand the GT90. Not sure if there are any diffusers that will fit though.

Oh, and did I say this thing is heavy?

Build Quality, knurling, threads, and anodization


The build quality is spot on. Nothing wobbles or doesn't fit the other parts. The knurling and flat spots on the body tube don't line up in any shape or form though. They are there for aesthetics alone.

Knurling on the battery tube is pretty rough and I like that. It doesn't feel slippery or anything. Just like with the first BLF GT, Lumintop has an all-aluminum flashlight including the bezel. I would have preferred a stainless steel bezel, but I can understand that would make the light quite a bit more expensive.

Anodization is fine, all around the light. After doing the beamshots the BLF GT90 got some scratches from being inside a box together with the other throw monsters. The beamshot locations are about 10-15 minutes' drive by car. So the light may have bumped into each other during the ride.

LEDs, Lens, Bezel, and Reflector


Instead of the 6V LEDs like the XHP50/70, Lumintop decided to use a Luminus SBT90-2 LED instead, which is a 3V LED. The LED is well centered inside the smooth reflector. The reflector looks identical to the one in the BLF GT. Exactly the same from what I can see. I'm curious if the light could produce a higher beam intensity if the reflector would have been optimized for this particular LED.

The SBT90.2 is a domeless LED which gives it an edge in terms of throw. LEDs with a flat surface have a more intense beam. Back in the day, all LEDs were equipped with a silicone dome. Until somebody found out that a flashlight without the dome could actually throw much farther. But that is history. These days, almost all long-range flashlights have domeless LEDs in them. Meaning: LED with a flat silicone surface and without a silicone dome.

When comparing the tint of the beam with other lights it's a little more on the rosier side (little more towards purple than towards green).

Dimensions:

  • Length:  315 mm ( 12.4 ”)
  • Head diameter:  134 mm ( 5.27 ”)
  • Reflector diameter: 120 mm (4.72")
  • Body diameter: 52mm/56mm  (2.05"/ 2.21")

Body diameter is measured on the narrowest and widest point of the battery tube.

Weight

  • Head: 1269 gr (44.75oz)
  • Battery tube with batteries: 894gr (31.53oz)
  • Complete:  2163g (  76.28oz)

So it's more than 2Kg.

Size comparisons with the best long-range flashlights currently available.

From left to right: Acebeam K75, Astrolux MF04, original Lumintop BLF GT, Lumintop BLF-GT90

Driver & User Interface:

The firmware is the NarsilM v1.2 according to Lumintop, see a BLF thread for more info about the NarsilM firmware here: http://budgetlightforum.com/node/54635.

If you have any questions about the firmware, that's the place to ask.

The firmware is pretty flexible and you can choose your desired settings.

Modes:

  • By default, it has a smooth ramping mode.
  • You can change this in the firmware to 12 other mode sets.

From OFF:

  • Press and hold: Low
  • Single-click: to last used brightness setting, mode memory
  • Double click: Turbo
  • Triple-click: Battery voltage check
  • 4 clicks: Lock Out mode, repeat to unlock.
  • 5 clicks: Momentary On mode for signaling (unscrew battery to go back to normal settings)

From ON:

  • Press and hold: Smoothly ramp up and down
  • Single-click:  turns the flashlight Off
  • Double click: Turbo
  • Triple-click: Battery voltage check
  • 4 clicks: Lock Out mode, repeat to unlock
  • 5 clicks: Momentary On mode

Low battery warning:

  • According to the manual it does blink when it reaches 3V. I just haven't seen it. I might have missed the blinking.

Lock-out mode:

  • Yes, the Lumintop BLF GT90 has a special Lock-out mode. You can get there from either the On or Off position by doing 4 rapid clicks.

PWM:

  • Nothing that I could notice by eye, which is what counts.

Firmware / UI Conclusion:

The UI can fit most people's needs. If you don't play with the switch too much, you'll be fine. Just use the ramping mode, Turbo, and Low, and that is good enough for this type of light! The Momentary ON is also pretty cool though, in case you need to do some morse coding... or annoy your neighbors.

Batteries and charging:

Button tops, unprotected 18650 cells. That's what the BLF GT90 takes. No protection. No flat tops. This makes it harder for most people to use. Protections would trip, most likely, and unprotected often have flat tops.

You can use 1-8 batteries.. as many as you want. I wonder if Lumintop would ever sell and extended version with 12 cells.. that would be funny looking.. and heavy. I wouldn't advise using only 1 battery though. It must pull a lot of currents. I can't really test that with my setup.

But there is a way around, by just unsoldering the protection board. Just like I did with the first BLF GT. If you take the battery carrier apart on the positive side you can easily unsolder the protection board. You need to do this 1 by one, put a screwdriver between the board and up to the next until you have done all 8 solder points. You probably need to do 2 rounds in order to unsolder it completely.

Performance:


Lumen measurements:

All output numbers are relative for my home-made Integrating Sphere. It is now set up with an Extech SDL400 Lux Meter for measurements. For extremely bright flashlights (above approx. 5000 lumens) I am adding an ND filter, either a Kenko PRO1D ND-16 filter or a Hakuba HG Wide 8x ND filter. The base measurement is done with a Convoy S2+ that has been tested at 137 lumens.

Batteries that I used for doing these tests are Samsung 30Q batteries like I do with most other flashlights so you can get a better understanding of the differences.

 

Lumintop BLF GT90ModeLumens
8* Samsung 30QLowest Ramp1,01 Lm
Highest Ramp2818 Lm
Turbo6513 Lm

Runtime:

Turbo slowly drop in output till about 5250 Lumens at 5 minutes before it drops down to roughly 1600Lumens. From then on, it slowly decreases output. Some timestamps:

  • 1 Hour: 1450 lumens
  • 2 Hours: 1290 lumens
  • 3 Hours: 1100 lumens
  • 4 Hours: 925 lumens
  • 5 Hours: 675 lumens

At the 5:15 mark, the light drops to about 280 lumens and at 5:23 it drops to 1 lumen.

Throw measurement:

Measurements were taken both indoors and outdoors with a professional Hagner E4-X Lux Meter. I took measurements at both 10m and 20 meters outdoors. 


Using Turbo mode , I get:

  • Outdoors (10m):  1818000cd (1.81Mcd) = 2697 meters throw / 1,68 miles
  • Outdoors (20m):  1720000cd (1.72Mcd) =  2623 meters throw / 1,63 miles

Beamshots

For the following beamshots I used a Canon 5d mk2, with 50mm lens, ISO 1600, F4, 1/2 sec.
Compared to the Astrolux MF04 (XHP35 Hi), Astrolux MF04S (XHP70.2), Lumintop BLF GT (XHP35 Hi) and Acebeam K75 (SBT90.2).

 The tower is approximately 650 meters (0.4 miles/2132 feet) away.

The Astrolux MF04S with XHP70 has a wider and brighter beam closeby. The farther away, the less reach it gets. The K75 is also an extremely powerful flashlight.

The following tower is approximately 450 meters away. You can see that the Astrolux MF04S with XHP70.2 has a much wider beam.

Disclaimer: This flashlight was bought at my own expense. I have not been paid to review, nor have I been holding back on problems or defects.

Overall conclusion

Pros:

  1. Farthest reaching LED flashlight
  2. Relatively easy UI
  3. Long runtime
  4. Use the number of batteries you like.

Cons

  1. No accessories included
  2. Only usable with button top unprotected 18650
  3. Huge
  4. No real aesthetic improvements over the original BLF GT
Marco

Author: Marco

Overall Rating: very good

After reviewing the best long-range LED flashlights in the world, I just had to pick up the BLF GT90! I just had to. The BLF GT90 is huge and heavy. By default, it accepts Non-protected Button-top 18650 batteries alone. You can use 1-8 batteries. 1 is not recommended because of the immense amount of current it requires. The downside of the GT90 is the lack of accessories and improvements, and therefore not reaching the 5 stars. 

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