[Bigmac_79]

Nitecore is a brand of flashlights that has been around for quite some time, and has a reputation for high-quality lights. Sysmax (the distributor of Nitecore) is no longer selling Jetbeam lights, and seems to be filling the gap with some new lights, including the MT series.



Thanks to Nitecore for providing the MT40 for review.

I’ll be reviewing the MT40 in two sections: first, I’ll discuss the light objectively (the facts about the light itself), then I’ll discuss the light subjectively (my impressions about the light's performance when used for specific applications). This is a high powered light designed for a good throw, so I'll be reviewing it as such. If you have any other specific applications you'd like the light tested for, let me know and I'll see what I can do.

5-Minute Overview

Below is a video "quick review" you can watch in just a few minutes, if you're not up for reading the full review right now:

[video=youtube;7QjGL6xVweg]https://www.youtube.com/watch?v=7QjGL6xVweg[/video]
This video is available in 720p HD, but defaults to a lower quality. To select the playback quality click the settings button (looks like a gear) after you've started the video.


Objective

Manufacturer's Specifications

Price: $70




Packaging

My review sample of the MT40 did not include the commercial packaging, and came to me wrapped in bubble wrap.


Construction




The MT40 is the largest in Nitecore's MultiTask series, running from four CR123 lithium primaries, four 16340 lithium-ion rechargeables, or two 18650 lithium-ion batteries.

The MT40 is made from aluminum, covered with black HAIII type anodizing to resist scratches and dents.

Now, let's take a closer look, starting from the front and working back.



The MT40 uses a Cree XM-L LED, centered in a deep smooth reflector. The large size of the reflector, and the smoothness of it, allow the MT40 to throw very well, even with the use of the XM-L.



The head of the MT40 has a thin band of knurling near the bezel, and tapers down to a smaller diameter near the body. On one side of the head is printed the Nitecore logo, website, model name and series name.

Near the base of the head is a raised knurled band, with smooth sections cut out. The MT40 uses a loosening/tightening of the head to switch between Turbo mode and a user selected mode. This ring acts as the main grip for easy turning of the head to loosen and tighten it.



The body of the MT40 is almost completely covered with knurling, with only a single smooth band down the middle.



The tail of the MT40 has a band of knurling, and two protrusions extending beyond the switch. The protrusions have oblong holes cut out to allow the MT40 to tail stand even when a lanyard is attached. The rubber cover of the switch features a letter "N" for Nitecore.

Now, it's time to take the light apart!



Without the use of tools, the MT40 comes apart into three pieces: the head, body, and tail.



Inside the head, the MT40 uses a spring to make contact with the positive terminal of the battery. This allows the MT40 to make contact with either button-top or flat-top batteries, though many flat-top batteries may have trouble connecting in series.

The threads between the head and body are thick, square-cut, non-anodized. They should stand up well to wear over time. Leaving them un-anodized allows them to make electrical contact with the head even when the head is loosened, which is essential for the UI of the MT series.



The threads between the body and tail are triangle-cut and anodized. The triangle cut tends to be a little weaker and less smooth, but the anodizing helps with this. Because they are anodized, if the tail is slightly loosened the tail will not make electrical connection with the body and the light will not turn on. This is good to prevent accidental activation while storing or transporting the light.



When a battery is inserted, it sits a bit behind the rim of the body.



The MT40 is able to tail stand on a flat surface, but is top-heavy enough that it's not very stable.

Dimensions



Accessories

My review sample did not include all the accessories listed in the specs, but only the holster.


User Interface

The MT40 features a two-stage user interface, controlled by the rear switch, and the position of the head (loose or tight). The MT40 has 6 modes available: Turbo, High, Medium, Low, SOS, Strobe. The Strobe is a "random" strobe, which varies it's timing in the flashes.

A half-press to the tail switch will turn the MT40 on momentarily, as long as the switch is held, and the light will turn off when the switch is released. A full press to the tail switch will click it into the constant on position, and the light will remain on until the switch is clicked again.

When the head is fully tightened, the light will always turn on in Turbo mode, and Turbo is the only mode available.

When the head is slightly loosened, the light will come on in the general mode used last. In this mode, turning the light off then back on in a short amount of time will advance to the next mode in the sequence of High -> Medium -> Low -> SOS -> Strobe. If you turn the light off or switch to Turbo mode, the light will remember the general mode you used last and will come back on in that mode the next time you use the light with the head loose. This mode memory does include the SOS and Strobe mode.


Action Shots

You can click on any of these shots to see them full size.

Light in Hand


White Wall (Low, Medium, High, Turbo, Mule)
ISO 100, f/3.3, 1/20"


BeamSlice


MugShot


Indoor Shots (Turbo)
ISO 100, f/3.3, 1"


Outdoor Shots (Control, Low, Medium, High, Turbo)
ISO 100, f/3.3, 2.5"


Performance

Submersion: I submersed the MT40 in about a foot of water for an hour, turning it on and off and switching modes (using the switch and rotating the head slightly) during that time, and the light shows no sign of water entering or damaging the light.

Heat: The MT40 gets warm quickly when on Turbo mode, but when using it outside in a good breeze the heat remains tolerable.

PWM: I was able to detect pulse-width modulation on the High, Medium, and Low modes of the MT40 (but not the Turbo mode) by viewing it through my camera set to a very short exposure. The PWM is not visible to the naked eye, and even with the camera it was harder to see than most other lights I've tested.

UPDATE 10/8/12: It turns out this is not actually pulse-width modulation, but rather is likely just "MCU signal noise". You can see a more in-depth discussion of this in post #15. This signal noise is not visible to the naked eye and does not seem to lower the efficiency of the circuit.

Drop: I dropped the MT40 from a height of about 1 meter onto various surfaces including grass, packed dirt, carpet, and wood. The light shows no cosmetic damage and still functions normally.

Reverse Polarity Protection: The MT40 features electronic reverse polarity protection, so if you insert the batteries backwards, the light will not turn on, but will not be damaged, and will resume normal function when the batteries are corrected. However, being a multi-cell light, it is still necessary to have all cells pointing the same direction at all times.

Over-Discharge Protection: The MT40 makes no claims of over-discharge protection, so I recommend only using protected cells when using lithium ions.

Spectral Analysis


All light that we see as white is actually made up of several different colors put together. The relative intensities of the different colors in the mix are what determine the tint of the white we see. For example, cool white LED's have a lot of blue, and warm white LED's have more red or yellow. This measurement was done on a home made spectrometer. The plot below the picture is corrected for the spectral sensitivity of the human eye. Note: the peak in the 900nm region doesn't really exist, it's a piece of the second-order spectrum that's showing up here because of the high intensity of the light source.

Output and Runtime


ANSI FL-1 runtime ratings are the time it takes for a light to fall to 10% of it's original output (counting from 30 seconds after turning the light on).

The vertical axis of the graphs below represents a relative brightness measurement using a home made light box. The horizontal axis is time in hours:minutes:seconds. Runtimes are stated in hours:minutes:seconds. These graphs may be truncated to show detail.

Mode Comparison







Throwing Distance

ANSI FL-1 standard for stating a light's throwing distance is the distance at which the peak beam intensity (usually at the center of the beam) is 0.25 lux. I calculate throwing distance and candela (lux at 1 meter) by measuring peak beam intensity at five different distances and using the formula lux*distance^2=constant.

Peak Beam Intensity: 37,596cd
Throw Distance: 388m
(throw distance was mis-typed, corrected on 10/8/12)

Subjective Review

Quick break down:

+ Bright spot with very even spill
+ Cutout tail allows tail stand with easy switch access
+ UI provides quick access Turbo and a mode of your choice
+ Very little heat buildup
+ Smooth beam even without a textured reflector
+ Solid construction
+ Smooth action when turning the head
+ Good grip
+ Anti-roll design without being awkward
+ Efficient head design

- Strobe and SOS are part of the general sequence, not hidden
- No anti-roll

Overall, I've enjoyed using the MT40. As a part of the Multitask series, the idea is that you can do a little customization of the light to adapt it to different circumstances. In theory, before you start your task you would loosen the head and choose what user-selectable mode you'll want. Then, during the task you'll have quick access to Turbo (when the head is tight) and whatever mode you selected (when the head is loose). For many tasks, I've found this to work well. I've found myself mostly using either Low or Strobe as the user-selectable mode, but Medium and High have been useful on occasion. As for the general idea of the UI, I find I like it better than just a click-through-all-modes interface. I still don't like it as much as a control ring to access all modes, but I do find it to be useful.

I was a bit worried about using the head-twisting to change modes, because I've had other lights that used that method and were unreliable. However, on the MT40 I've found the twisting of the head to be very smooth, and the mode changing is very reliable. Because of the quality of the threads and the good grip on the light, it's easy to tighten or loosen the head with a single hand.

It's kind of a funny thing, but I really like the design of the head on the MT40. It's designed at just about the right angle to be parallel to a flat surface when you lay the light on it's side, and it sort of gives the MT40 a distinctive look for a little better style that other lights in it's class.

I'll also mention that I was impressed with the regulation of the MT40 -- all the modes I tested, even the Turbo mode, were very well regulated (you can see the graphs above).

The one real negative I've found is that the Strobe and SOS are part of the regular sequence for the user-selectable modes. I understand the idea is to just pick one and stick with it during your task, but at times I find I do what to switch my user selectable mode. In those cases, my preference is to be able to cycle through modes without going through the blinky modes. Ideally, I'd prefer those blinky modes to still be an option for the user-selectable mode, but be hidden in some way so they don't come up unless you really want them. I also wish the Low mode was a little lower, but I guess most people don't really carry a light this size for it's lowest output.

So, the MT40 is a good choice if you're looking for a large light with a wide range of outputs, and are willing to try a UI that might be a little different than what you've used before.


Long Term Impressions

I'll fill this part in after carrying the light for a while. If nothing get's added here, either I find nothing else worth noting about the light, or I end up not using it often.