candle lamp
Flashlight Enthusiast
The TK75 is high-output, 3xXM-L U2, 4x18650 flashlight from Fenix.
The production version sent to me came in the nice plastic case. Included inside is the light, user manual, warranty card, two extra o-rings, lanyard.
.
.
Manufacturer Specifications from user manual :
Notice : The above mentioned parameters (lab-tested by Fenix using ARB-L2 18650 rechargeable Li-ion batteries) are approximate and may vary between flashlights, batteries, and environments.
• Uses Cree XM-L (U2) LED with lifespan of 50,000 hours
• Uses foure 18650 rechargeable Li-ion batteries
• 185mm (Length) x 52.5mm (Diameter) x 87.5mm (Head)
• 510-gram weight (excluding batteries)
• Digitally regulated output - maintains constant brightness
• Low-voltage warning function to alert users to replace the batteries
• Reverse polarity protection guards against improper battery installation
• Over-heat protection to avoid high-temperature of the surface
• Dual button switch system in the front for quick switching
• Made of durable aircraft-grade aluminum
• Premium Type III hard-anodized anti-abrasive finish
• Toughened ultra-clear glass lens with anti-reflective coating
.
.
The hard (type III) anodizing is a matt black, with no chips or damage on my sample. There are identification labels on the head only. The lettering is clear and white gainst the background. The manufacturer, model name, and serial number are at the bottom of the head. The hot warning mark is just below the bezel ring.
.
.
The light has mainly 3 parts (i.e. head, battery tube, and tailcap). There is a battery carrier in the tube.
.
.
The light has a stainless steel scalloped bezel ring and a waterproof o-ring between the bezel ring and reflector. There are three thin and three thick cooling fins on the head. The head base of the light has a positive contact point to contact with the positive contact of the battery carrier. The wide negative contact rim surrounds the central positive contact.
.
.
The light uses AR coating lens, and the purple hue is reflected on it.
The TK75 has a large head and uses three cool white XM-L U2 emitters, each emitter is perfectly centered in their own deep and smooth reflector well. There are few very small bubbles around reflectors, but do not affect the beam quality in the real world. The wells overlap slightly, but each reflector is somewhat deep overall, so I would expect peripheral artifacts in the spill and the good throw of beam.
.
.
The TK75 uses electronic switches in the head to control on-off and mode switching. These are conveniently located right below the cooling fins on the head. The right switch controls on-off, and the left controls mode selection and output levels within each mode.
The switching travel is average like this kind of switch with average resistance, and provides audible click when engaged.
.
.
The light uses a plastic battery carrier that holds 4x18650 cells which are arranged in 2S2P. It looks much sturdier and well-made than earlier models. The positive & negative contact point on the carrier are all springs.
.
.
The positive contact plate is significantly raised, and the negative contact spring has good elasticity. So all types (i.e., true flat-tops, wide and small button-tops) of 18650's work fine. Longer cells may be somewhat tight, but all my protected high capacity (2600~3100mAh) cells fit. The battery carrier isn't reversible because it has positive and negative connection terminals on the one side only (i.e., the current is carried through the battery carrier). You should be careful to insert the 18650's into the battery carrier in the correct polarity.
.
.
The positive contact point is very nicely fillet curved, so doesn't seem it may catch on the wrapper on the flat cells when removing them. There is haunched part outside the positive contact point will help to remove the batteries from the carrier.
.
.
You can see the fully loaded battery carrier with unprotected & protected cells. I don't have any issue to insert my shortest & longest 18650 cells into the carrier. But note that the cells with longer & wider diameter will have little difficulty when inserting into or removing from the battery carrier. It introduces no rattle even when I shake the light laterally when it's fully loaded with 18650's unprotected in my sample. Note that only 4x18650 li-ion cells can be used in the light (i.e., it doesn't support multiple CR123A or RCR123A).
.
.
Screw threads at the head & tail side are trapezoidal & square cut, and seems good quality. Both male & female threads on the head, battery tube, and tailcap are fully anodized, but it doesn't really matter since the current is carried though the battery carrier only. However lock-out is still possible if you unscrew the tailcap or head two full turns or more when not in use. They are smooth with no cross-threading or squeaking on my sample.
.
.
The battery tube continues the cylindrical shape. The overall checkered pattern of the handle has many segments which also have a large number of tiny concentric ring ridges running along. This pattern gives a very good grip. Tube walls are as thick as most of the multi 18650 high-output lights I have reviewed.
.
.
There are four couples of holes at the rear end of the tailcap for lanyard attachment.
.
.
You can attach the lanyard came with the light as shown above. The light can tailstand with the lanyard attached stably.
.
.
From left to right, VicLite 18650 protected, Blackshadow Terminator, Niteye EYE40, Fenix TK75, Xtar S1.
.
.
The head size & body weight excluding battery of TK75 & S1 are as follows :
TK75 - 87.9mm / 506g, S1 - 83.4mm / 877g
.
.
The gripability is good. The build feels solid, and I find handling & balance of the light is good. Overall build quality is very high.
.
.
Measured Dimensions & Weight
.
.
User Interface
There are two modes (i.e., general mode & flashing mode).
On-off is controlled by the right switch and output mode switching is controlled by the left switch on the head.
Cick the right switch to turn the light on-off. Click the left switch to advance through the output states.
1) General mode
The general (or constant) output mode is the default setting when you turn the light on. Press the left switch to cycle through Low –> Med. –> High –> Turbo output, in a repeating cycle. The light has output level memory, and remembers the last output level used when you turn the light off and back on, even after a battery change.
2) Flashing mode
The "hidden" Strobe, SOS are accessed by clicking and holding the side button switch for one second and three seconds respectively. A single press on the side switch will return to the memorized output level in general mode. The flashing mode has no memory.
.
.
Standby Current Drain
Due to the electronic side switches, the light has a small current when the battier carrier is loaded with cells and in contact to the head. I measured this current as 54.2μA with 4xVicLite 18650 (2600mAh) cells. Since the cells are arranged in 2S2P for 4x18650 cells, that would translate into around 10 years before the cells would be fully drained. If you want to break this current, store the light locked-out by loosening the head or tailcap or remove the carrier from the battery tube when not in use.
.
.
PWM
The light shows no sign of PWM at any output levels. I do think 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
Runtime performance is very good and flat regulation is evident on Turbo I tested. I could see the light dropped down to a very low output, instead of completely shutting off when the battery protection circuit was reached. The above runtime labelled as "Turbo-Accu." is an accumulated runtime for Turbo output. Regulation is maintained very nicely through Turbo mode on 4x18650 batteries.
The TK75 steps down on Turbo to High after around 20 mins runtime. This is a timed drop-down considering the battery depletion, 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.
The runtime accumulated Turbo output last on VicLite 18650 (2600mAh) is appr. 39 mins in my test. While it's appr. 67 mins on NLTEK18650 (3000mAh).
The runtime for 10% output of accumulated Turbo on VicLite & NLTEK are appr. 146 mins & 84 mins in my test.
* Note that the original cell of the NLTEK is LGABD11865 (3000mAh), and its maximum charging voltage is 4.35v for full capacity. But charged it 4.2v for runtime test, so the capacity is about 2700mAh reduced with about 300mAh.
There are three distinct step-downs (i.e., Turbo to High, High to Med., Med. to Low) at the stage of battery depletion. I could see there was times flashing or blinking to indicate low voltage on low output level.
[New 13.01.09]
I've added runtime for non-accumulated Turbo output on NLTEK 18650 (3000mAh). The runtime for 10% output of non-accumulated Turbo on VicLite & NLTEK are appr. 196 mins & 198 mins respectively. The difference of the entire runtime between two 18650's is almost imperceptible, while the High output duration on NLTEK is longer than VicLite by 10 mins. [New 13.01.09]
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[New 13.01.08]
Relative Output Comparison
[New 13.01.08]
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Beamshot
1. White door beamshot
- ISO100, F/10.0, 1/200sec, Auto white balance
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- ISO100, F/10.0, 1/400sec, Auto white balance
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- ISO100, F/10.0, 1/640sec, Auto white balance
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- ISO100, F/10.0, 1/1000sec, Auto white balance
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2. Indoor beamshot (about 7m from the target)
- ISO100, F/2.8, 1/8sec, Auto white balance
- Control Shot
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- TK75 (XM-L U2)
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- S1 (XM-L U2)
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3. 55m Outdoor Beamshot
- ISO100, F/2.8, 1sec, Auto white balance
- Control Shot
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- TK75 (XM-L U2)
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- S1 (XM-L U2)
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4. 60~65m Outdoor Beamshot
- ISO100, F/2.8, 1sec, Auto white balance
- Control Shot
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- TK75 (XM-L U2)
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- S1 (XM-L U2)
.
.
.
.
5. 140m Outdoor Beamshot
- ISO100, F/2.8, 1sec, Auto white balance
- Control Shot
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- TK75 (XM-L U2)
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- S1 (XM-L U2)
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.
.
6. 150m Outdoor Beamshot
- ISO100, F/2.8, 1sec, Auto white balance
- Control Shot
.
.
- TK75 (XM-L U2)
.
.
- S1 (XM-L U2)
.
.
.
.
[New 13.02.14] Beamshot for TK75 & K40
7. 55m Outdoor Beamshot
- ISO100, F/2.8, 1sec, Auto white balance
-Control Shot
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-K40
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.
- TK75
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.
.
.
8. 60~65m Outdoor Beamshot
- ISO100, F/2.8, 1sec, Auto white balance
- Control Shot
.
.
- K40
.
.
- TK75
.
.
.
.
9. 140m Outdoor Beamshot
- ISO100, F/2.8, 1sec, Auto white balance
- Control Shot
.
.
- K40
.
.
- TK75
.
.
.
.
10. 150m Outdoor Beamshot
- ISO100, F/2.8, 1sec, Auto white balance
- Control Shot
.
.
- K40
.
.
- TK75
.
.
[New 13.02.14]
.
.
The production version sent to me came in the nice plastic case. Included inside is the light, user manual, warranty card, two extra o-rings, lanyard.
.
.
Manufacturer Specifications from user manual :
Notice : The above mentioned parameters (lab-tested by Fenix using ARB-L2 18650 rechargeable Li-ion batteries) are approximate and may vary between flashlights, batteries, and environments.
• Uses Cree XM-L (U2) LED with lifespan of 50,000 hours
• Uses foure 18650 rechargeable Li-ion batteries
• 185mm (Length) x 52.5mm (Diameter) x 87.5mm (Head)
• 510-gram weight (excluding batteries)
• Digitally regulated output - maintains constant brightness
• Low-voltage warning function to alert users to replace the batteries
• Reverse polarity protection guards against improper battery installation
• Over-heat protection to avoid high-temperature of the surface
• Dual button switch system in the front for quick switching
• Made of durable aircraft-grade aluminum
• Premium Type III hard-anodized anti-abrasive finish
• Toughened ultra-clear glass lens with anti-reflective coating
.
.
The hard (type III) anodizing is a matt black, with no chips or damage on my sample. There are identification labels on the head only. The lettering is clear and white gainst the background. The manufacturer, model name, and serial number are at the bottom of the head. The hot warning mark is just below the bezel ring.
.
.
The light has mainly 3 parts (i.e. head, battery tube, and tailcap). There is a battery carrier in the tube.
.
.
The light has a stainless steel scalloped bezel ring and a waterproof o-ring between the bezel ring and reflector. There are three thin and three thick cooling fins on the head. The head base of the light has a positive contact point to contact with the positive contact of the battery carrier. The wide negative contact rim surrounds the central positive contact.
.
.
The light uses AR coating lens, and the purple hue is reflected on it.
The TK75 has a large head and uses three cool white XM-L U2 emitters, each emitter is perfectly centered in their own deep and smooth reflector well. There are few very small bubbles around reflectors, but do not affect the beam quality in the real world. The wells overlap slightly, but each reflector is somewhat deep overall, so I would expect peripheral artifacts in the spill and the good throw of beam.
.
.
The TK75 uses electronic switches in the head to control on-off and mode switching. These are conveniently located right below the cooling fins on the head. The right switch controls on-off, and the left controls mode selection and output levels within each mode.
The switching travel is average like this kind of switch with average resistance, and provides audible click when engaged.
.
.
The light uses a plastic battery carrier that holds 4x18650 cells which are arranged in 2S2P. It looks much sturdier and well-made than earlier models. The positive & negative contact point on the carrier are all springs.
.
.
The positive contact plate is significantly raised, and the negative contact spring has good elasticity. So all types (i.e., true flat-tops, wide and small button-tops) of 18650's work fine. Longer cells may be somewhat tight, but all my protected high capacity (2600~3100mAh) cells fit. The battery carrier isn't reversible because it has positive and negative connection terminals on the one side only (i.e., the current is carried through the battery carrier). You should be careful to insert the 18650's into the battery carrier in the correct polarity.
.
.
The positive contact point is very nicely fillet curved, so doesn't seem it may catch on the wrapper on the flat cells when removing them. There is haunched part outside the positive contact point will help to remove the batteries from the carrier.
.
.
You can see the fully loaded battery carrier with unprotected & protected cells. I don't have any issue to insert my shortest & longest 18650 cells into the carrier. But note that the cells with longer & wider diameter will have little difficulty when inserting into or removing from the battery carrier. It introduces no rattle even when I shake the light laterally when it's fully loaded with 18650's unprotected in my sample. Note that only 4x18650 li-ion cells can be used in the light (i.e., it doesn't support multiple CR123A or RCR123A).
.
.
Screw threads at the head & tail side are trapezoidal & square cut, and seems good quality. Both male & female threads on the head, battery tube, and tailcap are fully anodized, but it doesn't really matter since the current is carried though the battery carrier only. However lock-out is still possible if you unscrew the tailcap or head two full turns or more when not in use. They are smooth with no cross-threading or squeaking on my sample.
.
.
The battery tube continues the cylindrical shape. The overall checkered pattern of the handle has many segments which also have a large number of tiny concentric ring ridges running along. This pattern gives a very good grip. Tube walls are as thick as most of the multi 18650 high-output lights I have reviewed.
.
.
There are four couples of holes at the rear end of the tailcap for lanyard attachment.
.
.
You can attach the lanyard came with the light as shown above. The light can tailstand with the lanyard attached stably.
.
.
From left to right, VicLite 18650 protected, Blackshadow Terminator, Niteye EYE40, Fenix TK75, Xtar S1.
.
.
The head size & body weight excluding battery of TK75 & S1 are as follows :
TK75 - 87.9mm / 506g, S1 - 83.4mm / 877g
.
.
The gripability is good. The build feels solid, and I find handling & balance of the light is good. Overall build quality is very high.
.
.
Measured Dimensions & Weight
.
.
User Interface
There are two modes (i.e., general mode & flashing mode).
On-off is controlled by the right switch and output mode switching is controlled by the left switch on the head.
Cick the right switch to turn the light on-off. Click the left switch to advance through the output states.
1) General mode
The general (or constant) output mode is the default setting when you turn the light on. Press the left switch to cycle through Low –> Med. –> High –> Turbo output, in a repeating cycle. The light has output level memory, and remembers the last output level used when you turn the light off and back on, even after a battery change.
2) Flashing mode
The "hidden" Strobe, SOS are accessed by clicking and holding the side button switch for one second and three seconds respectively. A single press on the side switch will return to the memorized output level in general mode. The flashing mode has no memory.
.
.
Standby Current Drain
Due to the electronic side switches, the light has a small current when the battier carrier is loaded with cells and in contact to the head. I measured this current as 54.2μA with 4xVicLite 18650 (2600mAh) cells. Since the cells are arranged in 2S2P for 4x18650 cells, that would translate into around 10 years before the cells would be fully drained. If you want to break this current, store the light locked-out by loosening the head or tailcap or remove the carrier from the battery tube when not in use.
.
.
PWM
The light shows no sign of PWM at any output levels. I do think 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
Runtime performance is very good and flat regulation is evident on Turbo I tested. I could see the light dropped down to a very low output, instead of completely shutting off when the battery protection circuit was reached. The above runtime labelled as "Turbo-Accu." is an accumulated runtime for Turbo output. Regulation is maintained very nicely through Turbo mode on 4x18650 batteries.
The TK75 steps down on Turbo to High after around 20 mins runtime. This is a timed drop-down considering the battery depletion, 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.
The runtime accumulated Turbo output last on VicLite 18650 (2600mAh) is appr. 39 mins in my test. While it's appr. 67 mins on NLTEK18650 (3000mAh).
The runtime for 10% output of accumulated Turbo on VicLite & NLTEK are appr. 146 mins & 84 mins in my test.
* Note that the original cell of the NLTEK is LGABD11865 (3000mAh), and its maximum charging voltage is 4.35v for full capacity. But charged it 4.2v for runtime test, so the capacity is about 2700mAh reduced with about 300mAh.
There are three distinct step-downs (i.e., Turbo to High, High to Med., Med. to Low) at the stage of battery depletion. I could see there was times flashing or blinking to indicate low voltage on low output level.
[New 13.01.09]
I've added runtime for non-accumulated Turbo output on NLTEK 18650 (3000mAh). The runtime for 10% output of non-accumulated Turbo on VicLite & NLTEK are appr. 196 mins & 198 mins respectively. The difference of the entire runtime between two 18650's is almost imperceptible, while the High output duration on NLTEK is longer than VicLite by 10 mins. [New 13.01.09]
.
.
[New 13.01.08]
Relative Output Comparison
[New 13.01.08]
.
.
Beamshot
1. White door beamshot
- ISO100, F/10.0, 1/200sec, Auto white balance
.
.
- ISO100, F/10.0, 1/400sec, Auto white balance
.
.
- ISO100, F/10.0, 1/640sec, Auto white balance
.
.
- ISO100, F/10.0, 1/1000sec, Auto white balance
.
.
2. Indoor beamshot (about 7m from the target)
- ISO100, F/2.8, 1/8sec, Auto white balance
- Control Shot
.
.
- TK75 (XM-L U2)
.
.
- S1 (XM-L U2)
.
.
.
.
3. 55m Outdoor Beamshot
- ISO100, F/2.8, 1sec, Auto white balance
- Control Shot
.
.
- TK75 (XM-L U2)
.
.
- S1 (XM-L U2)
.
.
.
.
4. 60~65m Outdoor Beamshot
- ISO100, F/2.8, 1sec, Auto white balance
- Control Shot
.
.
- TK75 (XM-L U2)
.
.
- S1 (XM-L U2)
.
.
.
.
5. 140m Outdoor Beamshot
- ISO100, F/2.8, 1sec, Auto white balance
- Control Shot
.
.
- TK75 (XM-L U2)
.
.
- S1 (XM-L U2)
.
.
.
.
6. 150m Outdoor Beamshot
- ISO100, F/2.8, 1sec, Auto white balance
- Control Shot
.
.
- TK75 (XM-L U2)
.
.
- S1 (XM-L U2)
.
.
.
.
[New 13.02.14] Beamshot for TK75 & K40
7. 55m Outdoor Beamshot
- ISO100, F/2.8, 1sec, Auto white balance
-Control Shot
.
.
-K40
.
.
- TK75
.
.
.
.
8. 60~65m Outdoor Beamshot
- ISO100, F/2.8, 1sec, Auto white balance
- Control Shot
.
.
- K40
.
.
- TK75
.
.
.
.
9. 140m Outdoor Beamshot
- ISO100, F/2.8, 1sec, Auto white balance
- Control Shot
.
.
- K40
.
.
- TK75
.
.
.
.
10. 150m Outdoor Beamshot
- ISO100, F/2.8, 1sec, Auto white balance
- Control Shot
.
.
- K40
.
.
- TK75
.
.
[New 13.02.14]
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- TK75 supplied by Fenix for review. Thanks!
Last edited:
-got the light myself, but have to read your review 
