Lumintop GT Micro Flashlight Review

Lumintop has released the GT Micro flashlight, which runs the Narsil interface and uses a single 14500 cell. This Cree XP-L HI light has great throw!

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Official Specs and Features

Here’s a link to the Lumintop GT Micro Flashlight product page.

Versions

There’s just one body, but it’s available with an NW or CW tint.  Of course, if you’re interested in different cell sizes, the other bigger GT’s are options (GT, GT70, GT Mini).

Price

My GT Micro came from NealsGadgets.  Here’s an affiliate link where the price is $40 for the light, with cells available from $5-7.

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Short Review

Ok, I’ll agree that this isn’t the most practical of lights.  But how fun is a 14500 with >400m of throw.  Ridiculously fun, that’s how much fun.  Where else can you legally have ridiculous fun for $40?  I rest my case.

Long Review

The Big Table

Lumintop GT Micro
Emitter:	Cree XP-L HI
Price in USD at publication time:	$40
Cell:	14500
Turbo Runtime	High Runtime
LVP?	Yes
Switch Type:	E-Switch
Quiescent Current (A):
On-Board Charging?	No
Claimed Lumens (lm)	1000
Measured Lumens (at 30s)	902 (90.2% of claim)^
Claimed Throw (m)	400
Candela (Calculated) in cd (at 30s)	1742lux @ 5.392m = 50646cd
Throw (Calculated) (m)	450.1 (112.5% of claim)^
Item provided for review by:	Neals Gadgets
All my Lumintop reviews!

^ Measurement disclaimer:  Testing flashlights is my hobby. I use hobbyist-level equipment for testing, including some I made myself. Try not to get buried in the details of manufacturer specifications versus measurements recorded here; A certain amount of difference (say, 10 or 15%) is perfectly reasonable.

What’s Included

• Lumintop GT Micro
• Lanyard
• Spare o-rings (2)

Package and Manual

Fairly typical packaging for Lumintop.  Fliptop box, with custom foam inside.

I didn’t receive a manual with my package, but I expect that you will.

Build Quality and Disassembly

Like all the GT’s before it, the Micro is well made.

My single biggest (and really only) complaint is that I think the text printed on the side doesn’t look right-sized, and/or is not exactly where it should be.  But that’s an extremely minor complaint.

The tail cap has ridges for grip.  Knurling would be nice, but the threads on these GT’s are smooth enough that the tailcap removes easily anyway.

The head has come cooling fins, and they work well.

The threads are anodized and square-cut, and just very lightly lubed.  They’re very nice threads!

The cell tube is fully removable, and exactly the same on both ends.  It’s fully reversible.  Also, note that the anodized threads make for a very easy mechanical lockout!

The tailcap has a double spring, but it’s not extremely stiff.

The head has only a brass button.

The button top cell I used in this light (Efest 700mAh 14500) had plenty of room.  Any sized 14500 should work fine.

Size and Comps

Officially: Weight: Approximately 70g without cells
Dimensions: 36 mm Ø head x 105mm length

The GT Micro is surprisingly close to the Convoy S2+ in length.  But it’s a thrower, so there’s 1″ of reflector or more willing to explain that.  No big deal there.

Here’s the test light with the venerable Convoy S2+.  Mine’s a custom “baked” edition Nichia 219b triple.  A very nice 18650 light.

Here’s the Mini beside the Micro.  The Micro makes the Mini look huge!  But neither is huge.

And here’s the family.  I lack a GT70….  And yes I keep the GT in shorty mode.  I’d run it with 18350×4 just for giggles, if I could source the tube.

Retention and Carry

I managed to carry the Micro in my pocket a little, but generally, the best (and only included/intended) way is the lanyard.  The lanyard attaches through a hole on the tailcap.

Power and Runtime

I tested exclusively with the Efest IMR14500 700mAh seen below.  Since this is a FET light, on turbo you could get better performance with a better cell.

Having said that, even with this cell, performance was practically up to specification.  900 lumens on turbo is only ~10% difference from the claim, which is (for me) “close enough.”  There’s a heavy stepdown at around 3 minutes probably due to temperature.

The output on High looks much like the output on Turbo, except that there’s no discernible stepdown – the light never reaches the temperature required for a stepdown, so output on High just more or less tracks cell voltage.

The light does have LVP.  At 2.7V the main emitter flashes to warn the user, and at 2.6V the light shuts off completely.  In my tests I have “never shut off” because I stopped the test when the light hit the very low mode, long before the LVP would have kicked in anyway.

Pulse Width Modulation

Here you can see a “baseline” – a chart with almost no light hitting the sensor.

Then there’s the Ultrafire WF-602C flashlight, which has some of the worst PWM I’ve seen. It’s so bad that I used a post about it to explain PWM! Here are multiple timescales (10ms, 5ms, 2ms, 1ms, 0.5ms, 0.2ms) to make comparing this “worst” PWM light to the test light easier. That post also explains why I didn’t test the WF-602C at the usual 50us scale.

Stepped mode:

User Interface and Operation

There’s a single switch on the GT Micro.  It’s a side, e-switch, and has an indicating emitter under it.  The indicator is green.  The button is completely smooth but reasonably grippy.  Being familiar with the GT family, the photos below are deceiving.  The button is small – maybe 8mm.  Knowing the GT family, it’s tempting to think it’s much bigger.

The user interface is exactly as on the GT, which I just reviewed.  This will be a copy-paste of that UI.  I also always set these lights to stepped for testing, since it gives me something discreet to test.  But ramping is all the rage, and I like it fine too, so it’s nice to be able to switch between the two.

The user interface itself is a version of Narsil, by Tom E.  The version my light shows is Narsil 1.3.  (Check this by clicking 3x, then 2x, then 2x, and the version will be blinked.  1 blink, pause 3 blinks.)

The user interface is much too complex for my usual table, and I’m not going to undertake that here.  This Cheat Sheet is not my work! but is very useful, and thorough.

There are two groups.  One group has ramping, one group has discrete modes.  It’s possible to switch between ramping and discrete easily.  The default is ramping, and to switch to modes, first turn the light on, then hold the switch for 3.2s.  It’ll blink twice, pause, and blink once.  At that point, click once.  This disables ramping.  Once this is done, put the light down so you don’t change other settings (which is very easy to do.)  There are other things you could do to expedite the termination of programming, but just skip it, and wait.

Narsil is wonderful firmware.  It’s extremely versatile, and possible to change many (most? all?) of the settings of the light.

Modes and Currents

This is just for the stepped modes.

Mode	Mode Claimed Output (lm)	Claimed Runtime	Measured Lumens	Tailcap Amps
Turbo	1000	–	902	[FET]^
High	–	–	419	1.50
Medium	–	–	148	0.29
Low	–	–	11	0.03
Moon	–	–	0.5	0.01

^ I will no longer be testing current on the highest mode (or any full FET mode).  FET lights will take all the current available to them, so it’s meaningless for me to say my bench power can pump 20A into this light since I don’t know of any 14500 able to do that.  Essentially, with FET lights, use the best cell available to you!

LED and Beam

The emitter chosen for this tiny thrower is a Cree XP-L HI.  This has been the standard of choice for a long while for throwers, and it’s a fine choice here.  Another neat choice would have been an emitter by Osram, which is making the rounds in throwers now, and would have probably given this little thrower even more punch, and made it just that much more ridiculous fun.  But I happen to love XP-L HI’s, so it’s a good choice.

The light can be bought in NW or CW options.

LED Color Report (CRI and CCT)

The Cree XP-L HI used in the Lumintop GT Micro here is cool white – cooler as the output increases (from around 5600K to around 7200K).  The CRI is in the low 70’s, too.

Beamshots

These beamshots always have the following settings:  f8, ISO100, 0.3s shutter, and manual 5000K exposure. These photos are taken at floor level, and the beam hits the ceiling around 9 feet away.

Tint vs BLF-348 (KillzoneFlashlights.com 219b version) (affiliate link)

As you can see, I ended up with the CW version.  What better reason to throw in an Osram than that!

I compare everything to the Killzone 219b BLF-348 because it’s inexpensive and has the best tint!

Random Comparisons and Competitive Options

Here’s a link to a relevantly filtered page on parametrek.com.  I use that site a lot!  There really aren’t any other 14500 throwers.  There’s just nothing else like this light!

Conclusion

What I like

• Ridiculously fun 14500 thrower
• Narsil is a great UI
• Indicating side switch
• LVP

What I don’t like

• Doesn’t support AA
• At this point in size, it’s a bit weirdly shaped for the hand

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Notes

• This content originally appeared at zeroair.org.  Please visit there for the best experience!
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