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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.
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:
+ Compact & Slim
+ High output
+ Great regulation
+ Battery options
+ Independently driven emitters
+ Single switch - simple UI
+ Electronic lockout
+ Firm clip, screwed on
+ Beams converge nicely
+ Separate reflector for each emitter
+ Unique look
- No hard lockout
- Eco mode could be lower
In the review of the LD50, it's been obvious to me that as Fenix has grown confident with traditional design flashlights, they have room to be bold with some more unique ideas. In the LD50, I think they've really hit on something here, because this is now the brightest light I have that I would carry in my pocket regularly.
There is some ambiguity in the term EDC, which stands for Every Day Carry. Essentially there are many lights I Carry at some point Every Day: the AAA light on my keychain, the headlamp I use for nighttime chores, the 3x18650 I keep in my work bag, the big thrower I keep in my car, etc. But the real deal is the light I keep clipped in my pocket at all times. Usually my all-the-time pocket light is a single AA light with control ring, because 200 lumens is all I need for most general tasks that come up, and I like how small it is. At this time, I don't have any regular tasks that really call for more than 200 lumens, but if I know I'll be needing something more powerful I'll swap in a 1x18650 light for my pocket carry, for the extra run time and output. These single-emitter single-battery lights are getting pretty powerful, with 800-900 lumens becoming widely available in slim forms, and up to ~1000 lumens for some of the chunkier models. If I thought I'd need any more output than that (or more runtime than a single 18650 could give at those levels) then I'd grab a large 3x18650 light and clip it's holster to my belt or put it in my bag. Now, the LD50 has opened up another option. This light is slim enough that I'd be happy carrying it in a pocket all day/night without, and with two emitters and two batteries I get almost double the output or run time that I would from a single 18650 powered light. I'm really happy with how this worked out, and I hope we see more lights taking these sorts of innovative approaches to getting high output from an even more compact light).
Next, the output regulation of the LD50 is just great. You can look at the graphs yourself (above), but basically this what I like to see: very small drop in output at the start, flat output for the majority of the run, and a drop or curve down to a very low level of light that you can use to get new batteries or a new light in you hand. On Turbo mode, the LD50 does just what I expect from a mode labeled "Turbo" - maximum output for a short time, with a drop down to a sustainable output after that. For the most part I like the mode spacing, but I do wish that the Eco mode was more like 10 lumens, so I could drop it to 5 with only a single emitter running--this would increase run time and make this light even more versatile for regular pocket carry.
Speaking of using only a single emitter, that brings us to my next big + about the LD50: it's two emitters are driven independently but controlled by a single switch. With the independently driven emitters, you don't have to worry about matching battery voltage or even battery chemistry, which makes this light extremely versatile--I can just grab any 18650 or CR123 batteries out of my drawer and pop them in. If I don't have enough batteries on hand to power both sides, I can run just a single side alone. Obviously, if I intended to run just a single side most of the time, it would make more sense to get a single emitter light, but having this option makes the LD50 a great choice for an all-situations backup or emergency light. This feature also effectively doubles the output levels I have available to choose from. Unfortunately, this brings me to the one real drawback I've found on the LD50: it lacks a hard (physical) lockout mode. The side switch of the LD50 looks cool and is very comfortable to use, but being located on the side with so little protection, it can easily get bumped in a pocket or bag, especially when not in the holster. The holster adds some protection, but the button can still be pressed from within the holster. There is an electronic lockout available, but it is deactivated by holding the button for a few seconds, which while is less likely in a pocket or bag than a quick bump, is still a possible accidental event. You can read the comments below for some discussion about the possible reasons why this choice may have been made, but by leaving the threads on the tail caps un-anodized, the LD50 lacks a hard lockout option, which would have been a great advantage in my opinion, especially in this situation with the independently driven emitters.
A few other little things about the LD50: The clip is good. I've gotten several questions about it, and trust me, it's got a lot of holding power but is still easy to slip on to a pocket, belt, etc. The way they've designed it, the majority of the clip is above the plane of the light's body, but near the end is a dip that goes down into the groove between the body sections, which will be the contact point for the clip (it's a great integration of design features). The beams converge nicely, which means they're well aligned, which is even more impressive than usual considering their separation. Their separation also means that each beam get's it's own full reflector, with no cutouts to share sections with other emitters, so each has the maximum of it's light gathered and directed into the beam. Finally, they looks of the light (the contrast of the switch button and clip with the black light body in particular) make this look like a pretty classy light.
Overall, the LD50 is an excellent light that seems to create a new niche for itself - the multi-emitter pocket light. This is the brightest light I've reviewed that I considered to be continuously pocketable, and by a significant margin. If you're preparing to pack a punch with your pocket light, the LD50 is likely one of the best options you'll find.
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.
Don't forget to click "Like" after the page loads!
to my YouTube channel!
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.
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:
+ Compact & Slim
+ High output
+ Great regulation
+ Battery options
+ Independently driven emitters
+ Single switch - simple UI
+ Electronic lockout
+ Firm clip, screwed on
+ Beams converge nicely
+ Separate reflector for each emitter
+ Unique look
- No hard lockout
- Eco mode could be lower
In the review of the LD50, it's been obvious to me that as Fenix has grown confident with traditional design flashlights, they have room to be bold with some more unique ideas. In the LD50, I think they've really hit on something here, because this is now the brightest light I have that I would carry in my pocket regularly.
There is some ambiguity in the term EDC, which stands for Every Day Carry. Essentially there are many lights I Carry at some point Every Day: the AAA light on my keychain, the headlamp I use for nighttime chores, the 3x18650 I keep in my work bag, the big thrower I keep in my car, etc. But the real deal is the light I keep clipped in my pocket at all times. Usually my all-the-time pocket light is a single AA light with control ring, because 200 lumens is all I need for most general tasks that come up, and I like how small it is. At this time, I don't have any regular tasks that really call for more than 200 lumens, but if I know I'll be needing something more powerful I'll swap in a 1x18650 light for my pocket carry, for the extra run time and output. These single-emitter single-battery lights are getting pretty powerful, with 800-900 lumens becoming widely available in slim forms, and up to ~1000 lumens for some of the chunkier models. If I thought I'd need any more output than that (or more runtime than a single 18650 could give at those levels) then I'd grab a large 3x18650 light and clip it's holster to my belt or put it in my bag. Now, the LD50 has opened up another option. This light is slim enough that I'd be happy carrying it in a pocket all day/night without, and with two emitters and two batteries I get almost double the output or run time that I would from a single 18650 powered light. I'm really happy with how this worked out, and I hope we see more lights taking these sorts of innovative approaches to getting high output from an even more compact light).
Next, the output regulation of the LD50 is just great. You can look at the graphs yourself (above), but basically this what I like to see: very small drop in output at the start, flat output for the majority of the run, and a drop or curve down to a very low level of light that you can use to get new batteries or a new light in you hand. On Turbo mode, the LD50 does just what I expect from a mode labeled "Turbo" - maximum output for a short time, with a drop down to a sustainable output after that. For the most part I like the mode spacing, but I do wish that the Eco mode was more like 10 lumens, so I could drop it to 5 with only a single emitter running--this would increase run time and make this light even more versatile for regular pocket carry.
Speaking of using only a single emitter, that brings us to my next big + about the LD50: it's two emitters are driven independently but controlled by a single switch. With the independently driven emitters, you don't have to worry about matching battery voltage or even battery chemistry, which makes this light extremely versatile--I can just grab any 18650 or CR123 batteries out of my drawer and pop them in. If I don't have enough batteries on hand to power both sides, I can run just a single side alone. Obviously, if I intended to run just a single side most of the time, it would make more sense to get a single emitter light, but having this option makes the LD50 a great choice for an all-situations backup or emergency light. This feature also effectively doubles the output levels I have available to choose from. Unfortunately, this brings me to the one real drawback I've found on the LD50: it lacks a hard (physical) lockout mode. The side switch of the LD50 looks cool and is very comfortable to use, but being located on the side with so little protection, it can easily get bumped in a pocket or bag, especially when not in the holster. The holster adds some protection, but the button can still be pressed from within the holster. There is an electronic lockout available, but it is deactivated by holding the button for a few seconds, which while is less likely in a pocket or bag than a quick bump, is still a possible accidental event. You can read the comments below for some discussion about the possible reasons why this choice may have been made, but by leaving the threads on the tail caps un-anodized, the LD50 lacks a hard lockout option, which would have been a great advantage in my opinion, especially in this situation with the independently driven emitters.
A few other little things about the LD50: The clip is good. I've gotten several questions about it, and trust me, it's got a lot of holding power but is still easy to slip on to a pocket, belt, etc. The way they've designed it, the majority of the clip is above the plane of the light's body, but near the end is a dip that goes down into the groove between the body sections, which will be the contact point for the clip (it's a great integration of design features). The beams converge nicely, which means they're well aligned, which is even more impressive than usual considering their separation. Their separation also means that each beam get's it's own full reflector, with no cutouts to share sections with other emitters, so each has the maximum of it's light gathered and directed into the beam. Finally, they looks of the light (the contrast of the switch button and clip with the black light body in particular) make this look like a pretty classy light.
Overall, the LD50 is an excellent light that seems to create a new niche for itself - the multi-emitter pocket light. This is the brightest light I've reviewed that I considered to be continuously pocketable, and by a significant margin. If you're preparing to pack a punch with your pocket light, the LD50 is likely one of the best options you'll find.
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.
Last edited: