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Fenix is one of the most well-respected names in the high-end flashlight industry. They've got a wide range of flashlights of all types and sizes, but the LD50 is a bit different than most. It's flat profile and ability to drive two XM-L2 emitters, each from a separate battery, make it a light that can fulfill a unique niche. Presenting, the LD50:


Thanks to Fenix for providing the LD50 for review.

I’ll be reviewing the LD50 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). 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.

Video Review

Below is a video review of the LD50. Due to my old image hosting site closing down, I've got new restrictions on image uploads and have replaced the "Construction" section of my reviews with a more detailed video review.

Прямая ссылка на видео YouTube

This video is available in 1080p 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: 120 USD




Product Manual



Dimensions



Plus, here's a few shots with some good detail.













User Interface

The LD50 is basically two independent flashlights, stuck together and controlled by the same button. The side switch controls the five brightness modes and the Strobe mode.

To turn the light on, hold the button for about half a second, and the light will turn on in the last brightness mode you used. A quick press will cycle you through to the next brightness mode in the sequence Eco -> Low -> Mid -> High -> Turbo. Holding the button again for half a second will turn the light off.

If the light is off, holding the button for a full second will first turn the light on (at the half second mark), then turn it to Strobe (at the one second mark). Pressing the button again will turn the light back off.

If the light is on, holding the button for a full second will first turn the light off (at the half second mark), then turn it to Strobe (at the one second mark). Pressing the button again will turn the light back to the last brightness mode you were using.

Because the two sides are driven independently, either side will operate if the battery in the other side dies or is removed, or if one side is somehow damage. However, they are controlled by the same circuitry, so the two sides will always be at the mode setting. The only exception to this would be if the battery on one side was more depleted than the other, and when using a high output mode the more depleted battery was unable to supply the necessary current, resulting in one side dimmer than the other.

Action Shots

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

Light in Hand


MugShot


BeamSlice


White Wall
ISO 100, f/3.5, 1/20"


Indoor Shots
ISO 100, f/3.5, 1"
(Eco mode shot missing)

Outdoor Shots
ISO 100, f/3.5, 2.5"




Performance

Submersion: I submersed the LD50 under a foot of water for about an hour, clicking the switch several times. I found no evidence of water entering or damaging the light.

Heat: The LD50 gets warm after only a few minutes on Turbo, and is very hot by the end of the 10 minute pre-stepdown period. If you intend to force it back in to Turbo after the stepdown, you'll want to be using some method of cooling it (cold environment, hand directly on head to soak heat, etc.).

PWM: I could detect no pulse width modulation on any mode of the LD50.

Drop: I dropped the LD50 from about a meter onto various surfaces (including grass, carpet, dirt, and hard wood), and found no cosmetic or functional damage.

Reverse Polarity Protection: The LD50 claims reverse polarity protection, so I tried putting the battery in backwards and pressing the switch, then correcting the battery. I found no evidence of damage from the reversed polarity.

Over-Discharge Protection: The LD50 will begin to decrease in output, and flash a few times every few minutes when the batteries get low, so that's your signal to recharge or replace when using lions.


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

Turbo



High




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.





Subjective Review

Quick break down:

+

-

Coming soon...


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.