candle lamp
Flashlight Enthusiast
LD41 is single XM-L U2, dual switch interface, and high-output light on 4xAA's from Fenix.
Packaging is standard Fenix cardboard box with molded plastic insert. Inside you will find the LD41, a holster, lanyard, spare o-ring, spare tailcap switch boot cover, detailed user manual, warranty card, and etc.
Manufacturer Specification from user manual :
- Uses Cree XM-L U2 LED with a lifespan of 50,000 hours
- Uses four 1.5V AA (Ni-MH, Alkarine) batteries
- 175mm(Length)x40mm(Diameter)
- 180g weight (excluding batteries)
- Digitally regulated output maintains constant brightness
- Reverse polarity protection guards against improper battery installation
- Low-voltage reminder indicates when battery replacement is needed
- Anti-roll, slip-resistant body design
- Tactical tailcap switch with momentary-on function
- Tail mode switch, one click for brightness selection
- Made of durable aircraft-grade aluminum
- Premium Type III hard anodized anti-abrasive finish
- Toughened ultra-clear glass lens with anti-reflective coating
Notice : The above mentioned parameters (lab-tested with 2500mAh Ni-MH batteries) are approximate and may vary between flashlights, batteries, and environments.
.
.
The body plan of the LD41 is fairly straightforward. The light has a cylindrical head, but has a rectangular battery tube. The rounding off the four edges of the battery tube turns into more fluid & comfortable shape to outline & grip (i.e., comfortable to hold and handle).
Black anodizing (type III = HA) is matte finish, and without blemishes on my sample. Lettering is clearly legible in light gray, not bright white.
.
.
The light has mainly 2 parts (i.e. head and battery tube). There is a quality battery carrier as well.
.
.
There is "hot surface" warning on the head, and you will see the positive and negative contact on the back of the head. The light uses a fairly good smooth reflector, with reasonably deep proportions for the size of the head. There seems to be very mild texturing applied to the reflector surface which slightly dulls the finish, so I would expect reasonable throw with no doughnut-ring (Let's see it later on). Cool white XM-L U2 emitter is well centered on my sample. The light uses AR coating lens and the purple hue is reflected on it.
.
.
The crenellated bezel allows light to easily see if the LD41 is on when stood on its head (i.e., bezel down).
.
.
The light lacks knurling to speak of on the light, and instead has a large number of tiny ridges along the both narrow sides of the rectangular battery tube. While this helps a bit with grip, I think the light somewhat slippery overall, but it isn't slipperier than expected.
.
.
There are the positive and negative contact springs on the head, and are the circular negative contact plate surrounding the central positive contact plate on the battery carrier.
.
.
The light uses a battery carrier to hold the 4xAA cells. Quality seems good, but note that all the material is translucent plastic, aside from the contact plates and springs. But the carrier seems reasonable quality.
.
.
Batteries fit securely within the carrier, so they don't have a tendency to pop out easily, thanks to the well-made half-circled groove & small pieces in the middle of the carrier. There is absolutely no battery rattle inside the light if I shake the light laterally when it's fully loaded. The 4xAA cells are arranged as two in series, for each of the two channels of the carrier - the two channels are in series. So the battery carrier has a 4S with 2x2 layout.
.
.
Inside of the battery tube you will see there is a V-shaped notch along the tube. This corresponds to the groove visible on the battery carrier (i.e., you have to line up the groove on the battery carrier with this V-shaped notch during inserting the carrier). This is the only one way to insert the carrier.
.
.
The LD41 uses dual switches interface in the tailcap to control on-off and mode changing.
When seeing from the head to the base of the battery tube, you can see the larger rubber switch boot and the smaller rubber switch boot with a very small white plastic rod. (i.e., the battery tube only holds the switch rubber boots.) If you assemble the carrier & tube, the larger rubber booth and the smaller rubber booth with a plastic rod are linked to a mechanical (or physical) on-off clicky switch and a electronic mode changing switch on the battery carrier respectively.
.
.
The light has a reasonable number of anodized thick trapezoidal (nearly square-cut) screw threads (i.e., they should be durable and stable) at both head and battery tube, but that doesn't really matter too much to head lock-out since the current is carried through the battery carrier only and the negative spring contact is protruding. However lock-out is still possible, turning the head one and a half turns to the left on my sample.
.
.
There are 4 external screws tightly fixing the aluminum tailcap - which holds the switch rubber boot - to the battery tube. and the screws seem good quality.
The on-off switch is a forward clicky switch, and has a good feel but slightly stiffer than expected. The mode changing switch produces a definite but much quieter click sound & minimal travel than the on-off switch when pressed. The switches are intuitive, and work well.
.
.
The tailcap has four partially raised rims which provides comfortable activation of the switch. There is a slit through a rim which allows for lanyard attachment.
The light can tailstand, but there is a bit wobble, as the larger on-off switch does protrude out the tail end slightly on my sample
.
.
The gripability & handling the light is reasonably good.
The overall build quality is very high.
.
.
From left to right : Eneloop AA, Fenix LD10, Fenix E21, Fenix LD41, Fenix TK50.
.
.
Measured dimension & weight
.
.
The LD41 comes with a basic nylon holster with a velcro strap on the head. The light fits in the holster either head-up or head-down.
.
.
User Interface
On-off is controlled by the larger forward clicky switch (press-on for momentary, click for locked on), and mode changing is controlled by the smaller electronic switch. There are two modes (i.e., general mode & flashing mode).
1. General mode
Output changing is controlled by the smaller electronic switch. Click and release to advance through output modes, which proceed in sequence from Low -> Med. -> High -> Turbo, in repeating sequence. The light has mode memory, and remembers the last output level used when you turn the light off and back on, (even after a battery change).
You can't set the output level while the light is off. The electronic switch only works when the light is powered on by the on-off switch first.
2. Flashing mode
The Strobe is accessed by pressing and holding the smaller switch for more than about 1 sec. To access SOS, press and hold the smaller switch more than about 3 sec. To return to the general mode, just click the smaller switch once, or turn off & on the light. The flashing mode has no memory. The light always turns on in the memorized general mode, so there is no danger of strobing accidentally (also it means you can't directly access strobe without turning on the light in general mode first).
User Interface is good, and I like seeing the flashing mode well hidden.
.
.
Overheating Protection
After 30 mins of continuous runtime on Turbo output, LD41 drops down to Hi output for the rest of the time to avoid overheating the light. If Turbo is needed for extended run time, just turn off and on the light during working on Turbo or press the smaller switch once after dropping down to Hi.
.
.
Standby Current Drain
There is no standby current because the electronic switch only works when the light is turned on by the on-off switch first.
.
.
PWM
No sign of PWM at any level of the light, leading me to conclude the light is actually current-controlled as claimed. I notice there is neither buzzing sound nor tint-shift at all output levels with the naked eye on my sample.
.
.
Runtime
1. 4xEneloops AA
The runtime for 10% output of Turbo is appr. 310 mins in my test.
.
.
2. 4xEnergizer AA
The runtime for 10% output of Turbo is appr. 364 mins in my test.
.
.
3. 4xEneloops AA, 4xEnergizer AA
The above runtime labelled as "Trubo-Acc." is an accumulated runtime for turbo output.
Regulation is maintained very nicely through Turbo on both batteries (Ni-MH, Alkarine).
The LD41 steps down on turbo to High after 30 mins runtime, on both 4xEneloop's and 4xEnergizer's. This is a timed drop-down, not a thermal sensor feature to avoid overheating the light. As with the other Fenix lights, the regulation pattern and runtime efficiency of the current controlled circuit seems excellent.
[Update : Aug 30] There are always three distinct step-downs (i.e., Turbo to High, High to Med., Med. to Low) at the stage of battery depletion. I couldn't see there was flashing or blinking to indicate low voltage on low brightness level for hours, so turned the light off. The manual says "the circuit is programmed with a low voltage protection function. If low voltage is detected, it will enter into the low brightness level, it will blink three times a second every 5 minutes. To allow normal use, LD41 will not turn off automatically and will continue to work until the batteries are depleted." This tells why I couldn't see blinking to indicate low voltage on low for hours. [Update : Aug 30]
.
.
Beamshot
1. White door beamshot (about 50cm from the white door)
- ISO100, F/3.5, 1/100sec, Auto white balance
- Turbo
.
.
- High
.
.
- Med.
.
.
- Low
.
.
There is something of a greenish tint-shift in the corona around small hotspot, but it's not noticeable except up-close. The overall beam quality is good (i.e., No rings in the beam).
.
.
2. Indoor beamshot (about 7m from the target)
- ISO100, F/2.8, 1/3sec, Auto white balance
- Turbo
.
.
- High
.
.
- Med.
.
.
- Low
.
.
.
.
3. 55m Outdoor Beamshot
- ISO100, F/2.8, 1sec, Auto white balance
- Control shot
.
.
- Turbo
.
.
.
.
4. 60~65m Outdoor Beamshot
- ISO100, F/2.8, 1sec, Auto white balance
- Control Shot
.
.
- Turbo
.
.
The light has a reasonable amount of throw, and a nice transition from spot to spill.
.
.
* LD41 was supplied by Fenix for review.
Packaging is standard Fenix cardboard box with molded plastic insert. Inside you will find the LD41, a holster, lanyard, spare o-ring, spare tailcap switch boot cover, detailed user manual, warranty card, and etc.
Manufacturer Specification from user manual :
- Uses Cree XM-L U2 LED with a lifespan of 50,000 hours
- Uses four 1.5V AA (Ni-MH, Alkarine) batteries
- 175mm(Length)x40mm(Diameter)
- 180g weight (excluding batteries)
- Digitally regulated output maintains constant brightness
- Reverse polarity protection guards against improper battery installation
- Low-voltage reminder indicates when battery replacement is needed
- Anti-roll, slip-resistant body design
- Tactical tailcap switch with momentary-on function
- Tail mode switch, one click for brightness selection
- Made of durable aircraft-grade aluminum
- Premium Type III hard anodized anti-abrasive finish
- Toughened ultra-clear glass lens with anti-reflective coating
Notice : The above mentioned parameters (lab-tested with 2500mAh Ni-MH batteries) are approximate and may vary between flashlights, batteries, and environments.
.
.
The body plan of the LD41 is fairly straightforward. The light has a cylindrical head, but has a rectangular battery tube. The rounding off the four edges of the battery tube turns into more fluid & comfortable shape to outline & grip (i.e., comfortable to hold and handle).
Black anodizing (type III = HA) is matte finish, and without blemishes on my sample. Lettering is clearly legible in light gray, not bright white.
.
.
The light has mainly 2 parts (i.e. head and battery tube). There is a quality battery carrier as well.
.
.
There is "hot surface" warning on the head, and you will see the positive and negative contact on the back of the head. The light uses a fairly good smooth reflector, with reasonably deep proportions for the size of the head. There seems to be very mild texturing applied to the reflector surface which slightly dulls the finish, so I would expect reasonable throw with no doughnut-ring (Let's see it later on). Cool white XM-L U2 emitter is well centered on my sample. The light uses AR coating lens and the purple hue is reflected on it.
.
.
The crenellated bezel allows light to easily see if the LD41 is on when stood on its head (i.e., bezel down).
.
.
The light lacks knurling to speak of on the light, and instead has a large number of tiny ridges along the both narrow sides of the rectangular battery tube. While this helps a bit with grip, I think the light somewhat slippery overall, but it isn't slipperier than expected.
.
.
There are the positive and negative contact springs on the head, and are the circular negative contact plate surrounding the central positive contact plate on the battery carrier.
.
.
The light uses a battery carrier to hold the 4xAA cells. Quality seems good, but note that all the material is translucent plastic, aside from the contact plates and springs. But the carrier seems reasonable quality.
.
.
Batteries fit securely within the carrier, so they don't have a tendency to pop out easily, thanks to the well-made half-circled groove & small pieces in the middle of the carrier. There is absolutely no battery rattle inside the light if I shake the light laterally when it's fully loaded. The 4xAA cells are arranged as two in series, for each of the two channels of the carrier - the two channels are in series. So the battery carrier has a 4S with 2x2 layout.
.
.
Inside of the battery tube you will see there is a V-shaped notch along the tube. This corresponds to the groove visible on the battery carrier (i.e., you have to line up the groove on the battery carrier with this V-shaped notch during inserting the carrier). This is the only one way to insert the carrier.
.
.
The LD41 uses dual switches interface in the tailcap to control on-off and mode changing.
When seeing from the head to the base of the battery tube, you can see the larger rubber switch boot and the smaller rubber switch boot with a very small white plastic rod. (i.e., the battery tube only holds the switch rubber boots.) If you assemble the carrier & tube, the larger rubber booth and the smaller rubber booth with a plastic rod are linked to a mechanical (or physical) on-off clicky switch and a electronic mode changing switch on the battery carrier respectively.
.
.
The light has a reasonable number of anodized thick trapezoidal (nearly square-cut) screw threads (i.e., they should be durable and stable) at both head and battery tube, but that doesn't really matter too much to head lock-out since the current is carried through the battery carrier only and the negative spring contact is protruding. However lock-out is still possible, turning the head one and a half turns to the left on my sample.
.
.
There are 4 external screws tightly fixing the aluminum tailcap - which holds the switch rubber boot - to the battery tube. and the screws seem good quality.
The on-off switch is a forward clicky switch, and has a good feel but slightly stiffer than expected. The mode changing switch produces a definite but much quieter click sound & minimal travel than the on-off switch when pressed. The switches are intuitive, and work well.
.
.
The tailcap has four partially raised rims which provides comfortable activation of the switch. There is a slit through a rim which allows for lanyard attachment.
The light can tailstand, but there is a bit wobble, as the larger on-off switch does protrude out the tail end slightly on my sample
.
.
The gripability & handling the light is reasonably good.
The overall build quality is very high.
.
.
From left to right : Eneloop AA, Fenix LD10, Fenix E21, Fenix LD41, Fenix TK50.
.
.
Measured dimension & weight
.
.
The LD41 comes with a basic nylon holster with a velcro strap on the head. The light fits in the holster either head-up or head-down.
.
.
User Interface
On-off is controlled by the larger forward clicky switch (press-on for momentary, click for locked on), and mode changing is controlled by the smaller electronic switch. There are two modes (i.e., general mode & flashing mode).
1. General mode
Output changing is controlled by the smaller electronic switch. Click and release to advance through output modes, which proceed in sequence from Low -> Med. -> High -> Turbo, in repeating sequence. The light has mode memory, and remembers the last output level used when you turn the light off and back on, (even after a battery change).
You can't set the output level while the light is off. The electronic switch only works when the light is powered on by the on-off switch first.
2. Flashing mode
The Strobe is accessed by pressing and holding the smaller switch for more than about 1 sec. To access SOS, press and hold the smaller switch more than about 3 sec. To return to the general mode, just click the smaller switch once, or turn off & on the light. The flashing mode has no memory. The light always turns on in the memorized general mode, so there is no danger of strobing accidentally (also it means you can't directly access strobe without turning on the light in general mode first).
User Interface is good, and I like seeing the flashing mode well hidden.
.
.
Overheating Protection
After 30 mins of continuous runtime on Turbo output, LD41 drops down to Hi output for the rest of the time to avoid overheating the light. If Turbo is needed for extended run time, just turn off and on the light during working on Turbo or press the smaller switch once after dropping down to Hi.
.
.
Standby Current Drain
There is no standby current because the electronic switch only works when the light is turned on by the on-off switch first.
.
.
PWM
No sign of PWM at any level of the light, leading me to conclude the light is actually current-controlled as claimed. I notice there is neither buzzing sound nor tint-shift at all output levels with the naked eye on my sample.
.
.
Runtime
1. 4xEneloops AA
The runtime for 10% output of Turbo is appr. 310 mins in my test.
.
.
2. 4xEnergizer AA
The runtime for 10% output of Turbo is appr. 364 mins in my test.
.
.
3. 4xEneloops AA, 4xEnergizer AA
The above runtime labelled as "Trubo-Acc." is an accumulated runtime for turbo output.
Regulation is maintained very nicely through Turbo on both batteries (Ni-MH, Alkarine).
The LD41 steps down on turbo to High after 30 mins runtime, on both 4xEneloop's and 4xEnergizer's. This is a timed drop-down, not a thermal sensor feature to avoid overheating the light. As with the other Fenix lights, the regulation pattern and runtime efficiency of the current controlled circuit seems excellent.
[Update : Aug 30] There are always three distinct step-downs (i.e., Turbo to High, High to Med., Med. to Low) at the stage of battery depletion. I couldn't see there was flashing or blinking to indicate low voltage on low brightness level for hours, so turned the light off. The manual says "the circuit is programmed with a low voltage protection function. If low voltage is detected, it will enter into the low brightness level, it will blink three times a second every 5 minutes. To allow normal use, LD41 will not turn off automatically and will continue to work until the batteries are depleted." This tells why I couldn't see blinking to indicate low voltage on low for hours. [Update : Aug 30]
.
.
Beamshot
1. White door beamshot (about 50cm from the white door)
- ISO100, F/3.5, 1/100sec, Auto white balance
- Turbo
.
.
- High
.
.
- Med.
.
.
- Low
.
.
There is something of a greenish tint-shift in the corona around small hotspot, but it's not noticeable except up-close. The overall beam quality is good (i.e., No rings in the beam).
.
.
2. Indoor beamshot (about 7m from the target)
- ISO100, F/2.8, 1/3sec, Auto white balance
- Turbo
.
.
- High
.
.
- Med.
.
.
- Low
.
.
.
.
3. 55m Outdoor Beamshot
- ISO100, F/2.8, 1sec, Auto white balance
- Control shot
.
.
- Turbo
.
.
.
.
4. 60~65m Outdoor Beamshot
- ISO100, F/2.8, 1sec, Auto white balance
- Control Shot
.
.
- Turbo
.
.
The light has a reasonable amount of throw, and a nice transition from spot to spill.
.
.
* LD41 was supplied by Fenix for review.
Last edited:
one great light.
