Introduction
This light was provided free of charge by Nitecore Store for review.
The SRT9 is the newest model in the SmartRing Tactical (SRT) line. Nitecore SRT series lights offer infinite brightness adjustability via the twist of a magnetic ring near the head of the light while a tail switch controls general on/off.
The SRT9 features a Cree XHP50 emitter outputting 2150 lumens as well as ultraviolet, green, red, and blue emitters for multi-purpose versatility. The SRT9 uses two 18650 or four CR123A batteries. With a die-cast body, the SRT9 manages heat very well and is stronger than many other lights.
Here are the key review details in one table for the TL;DR crowd:
Unboxing
The SRT9 arrived in a retail box within a padded envelope. The box itself is rather compact at 2.75" wide, 7.25" tall, and 2.125" deep.
The SRT9 box is in the same style as other current Nitecore flashlights.
The front has quite a bit of information: model designation, emitter type, battery type, peak output, SmartRing explanation with image, and images showing the various emitters.
The back of the box has verbiage describing the design of the SRT9, its advantages, the multiple outputs and features of the SRT9, disposal safety, registrations, SYSMAX contact information, and a legal disclaimer.
The left side has a (not to scale) image of the SRT9.
The right side of the box promotes Law Enforcement and Search as intended uses for the SRT9. It also shows the key output, impact, and water resistance specifications.
The bottom of the box has a single adhesive label with model information and barcode.
Opening the box, we find the SRT9 in a plastic carrier with the accessories underneath.
Included is a holster, manual, warranty card, spare o-rings, lanyard, and already-attached pocket clip.
The manual is in 9 languages (English, Spanish, German, French, Polish, Japanese, Romanian, Chinese, and I believe Korean); each language's section is complete as the text is quite small.
It can be accessed online here:
http://flashlight.nitecore.com/pdf/SRT9_UM_EN.pdf
Nitecore backs the SRT9 with a 5 year warranty, as advertised on the box as well as in the manual.
Design
The SRT9 is a compact side-by-side 18650 light with a 40mm head. This form factor is shared with the EC4S, EC4SW, and EC4GT, so traffic wands and other accessories are interchangeable between these models.
Necessary to accommodate the tail switch, the SRT9 abandons the thumbscrew used to secure the battery door on the other lights to a new design that clicks to lock the tail cap from both sides using spring-loaded pins that extend from the main tube.
The SRT9 feels more aggressive in hand than the EC4SW thanks to deep cooling fins around the head and down two sides.
Nitecore states the SRT9 is 5.83 in. (148 mm) long with a head diameter of 1.57 in. (40 mm). My measurements confirmed these numbers exactly. Weight without batteries was also verified at 7.9 oz. (224 g).
The SRT9's size can be appreciated when put next to other lights. L to R: ThorFire C8S (18650), Nitecore TM03 (18650), Nitecore EC4SW (18650*2), Nitecore SRT9 (18650*2), Nitecore SRT7GT (18650), Olight R50 Pro (26650), Convoy S2+ (18650), Manker E11 (AA).
The head of the SRT9 has a stainless bezel that is flat in shape and color. There are 5 small indentations machined into the inner part of the bezel. When the SRT9 is placed head-down on a flat surface, no light can escape past the flat bezel – so users should take appropriate care to avoid unintentionally depleting the battery this way.
The glass is AR-coated mineral glass. The reflector is of the orange peel variety; this produces a floody beam that hides the imperfections introduced by the multi-die XHP50 emitter. The reflector was free of visible defects.
The central quad-die Cree XHP50 emitter is perfectly centered. The Green, Red, Blue, and UV emitters are in shallow wells bored into the central reflector.
The Nitecore logo, website, model name, registration, and disposal information are all located on the head of the SRT9. The embossing is clean but the text does blend together from a distance given the thick typeface and compact nature of the printing. This isn't a bad thing; many users prefer to see text as contained as possible.
Just to the side is a HOT logo.
Opposite of the main embossing is the individual light's serial number. It is extremely small and hardly noticeable.
Below the embossing, cooling fins extend around the circumference of the SRT9. These are deeper than on the EC4S, though sections alternate in length to give some style and grip above the magnetic ring.
The magnetic ring switch - the signature feature of the SRT line - has good knurling and channels for grip.
The narrow sides of the battery tube are identical with a checkerboard-style grip.
The flat sides of the battery tube are not the same. While both have cooling fins, one has the battery indicator light while the other side has the pocket clip.
The battery indicator light is small, blue, and flashes every 2 seconds when the light is on standby or when the battery is below 50%. Below about 10%, the indicator light flashes rapidly.
The titanium coated stainless steel pocket clip is attached with Torx ("star drive") screws. The clip is smooth and unobtrusive in hand or in a jacket pocket. It is however difficult to use because of the tail cap arms; these are taller than the clip and obscure access to the clip when trying to slide the SRT9 clip onto a pocket.
The clip is not strong or textured enough to hold onto the brim of a hat (though too heavy to practically use this way anyway). As the SRT9 won't be "front pocket carry" for most people, I found the clip works best when clipped directly to the waist of a pair of pants or a belt. Like this, it holds the SRT9 well. If more strenuous activity is likely, the holster should be used.
The tail has a forward clicky switch that enables momentary on; if the ring has been left in an "on" position and the tail switch is half-pressed, the light will turn on so long as the tail switch is held. The switch boot has a "N" in the pattern and a spare switch boot is included. Pressure required to activate the switch is on the firm side of moderate.
The tail itself – the battery door – attaches via two spring-loaded pins that extend outward from the battery tube into sockets in the arms of the tail cap. These have to be pressed to allow the tail cap to slide into place. A good bit of pressure is then required on the tail to get it to securely clip onto the pins.
Those arms extend rearward past the switch. This allows the SRT9 to tailstand, though only on very flat surfaces. Indoors it should be no problem, but finding appropriately flat surfaces outdoors may be a challenge.
A slot on each side of the tail allows the lanyard to be attached. The holes are large so threading the lanyard is easy The tail-end location keeps using the lanyard from feeling awkward. Given the size of the holes, though, Nitecore could have used a split/dual hole design to keep the lanyard loop to the side instead of over the tail end where it affects tailstanding.
One design feature that I noticed… the arms on the battery door have chevron-shaped lines. A very similar design is on the Nitecore Tube keychain lights.
While laying the Tube next to the SRT9, I inadvertently confirmed that the SRT9's selector ring is magnetic. It attracted the Tube's keyring and was strong enough to hold the weight of the Tube when lifted.
As with many other Nitecore lights, button top batteries are required. The screws on the board in the tail seemed to prevent flat tops or incorrectly inserted batteries from making contact.
The springs are gold colored and there are both inner and outer springs. A custom gasket around the tail cap ensures IPX-8 water resistance to 2 meters underwater. Nitecore includes a spare gasket.
The SRT9's battery tube has channels to hold the batteries in place during loading. These metal sections between the batteries also help to absorb and radiate heat from the light and the batteries.
The holster fits the SRT9 well whether the SRT9 is stored head up or head down. It has a D-ring, belt pass-through loop, and hook-and-loop – so it can be worn a variety of ways.
Before continuing to the performance information, here are a few more pictures of the SRT9 in its natural habitat (outside)!
Performance
The XHP50 LED is a quad-die emitter, which would naturally produce a crosshair in the beam. At a very close distance, this is still visible.
Nitecore uses an orange peel reflector to help remove these artifacts at a normal distance. The resulting beam has a hotspot with soft edges. The corona is wide and transitions smoothly into the spill. The wells for the colored LEDs do not seem to affect the beam at all.
The majority of the beam appears creamy neutral with some cool blue at the outer edges of the spill.
To demonstrate the relative color balance, here is the SRT9 surrouned by lights with emitters of various tints and temperatures.
L to R: Astrolux S41S with neutral 219B, Nitecore C1 with cool XHP35 HD E2, Convoy S2+ with cool XM-L U2 1B, Nitecore SRT9 with cool XHP50, Olight S1R with cool XM-L2, BLF348 with neutral 219B, and Lumintop Tool with warm 219B.
Nitecore rates the SRT9 at 2150 lumens on Turbo. Nitecore used Nitecore 3400mAh button-top protected 18650 batteries for official specifications so I used the same spec Nitecore batteries (model NL189) for my tests. 4xCR123A batteries can be also used. Flat top batteries do not work.
At turn-on, the SRT9 output a solid 2273 lumens. At 30 seconds, I found output at 2153 lumens. This matches the 2150 lumen rating provided by Nitecore exactly.
What didn't match rated specifications was Turbo runtime, though it was a good surprise. Nitecore states runtime at 1 hour; I found output didn't drop to 10% (ANSI FL1 standard) until 2 hours and 20 minutes into the test. While output dropped about 200 lumens in the first 2 minutes, the output was then linear until the batteries were nearly empty. 50% was reached at 68 minutes; 10% was reached at 140 minutes. An 80mm PC fan running to produce some airflow. Ambient temp was 78F.
The SRT9 has Nitecore's "Advanced Temperature Regulation (ATR) module" designed to keep the LED from overheating, yet the light dissipated heat so well that ATR didn't appear to step in at any point during testing. The SRT9 remained cool with head temperature peaking at 120F (49C) 9 minutes into the Turbo test. The die-cast design is very effective at distributing heat.
Nitecore rates the Ultralow mode at 0.1 lumens. The lowest that I could get the SRT9 to produce any light at with a fresh battery was at about 2.7 lumens. No runtime test was conducted; Nitecore rates it at 250 hours.
As most people will use the SRT9 somewhere in-between Turbo and Ultralow, I ran a test with the light at as close to 1000 lumens as I could. At 30 seconds, the SRT9 was outputting 996 lumens. The output climbed on its own, peaking at 1049 lumens at minute 33. It then dropped to 938 lumens by minute 42. That output was maintained until 2:25, at which point a fairly linear drop towards 0 began. 50% of initial output was reached at 3:06 with 10% hit at 3:27.
Both outputs tested, graphed together:
I did detect PWM both with the "mirror test" and via camera when the SRT9 was operating at the low end of its output range. On Ultralow, I could easily observe it on a wall. At high output levels I did not detect it visually so it is either high frequency or non-existent there.
I tested throw distance at 1.46 meters and the resulting candela was 9,810 - equivalent to 289 meters of throw. This outperforms Nitecore's rating of 246 meters (289 yards).
My lumen measurement device has not been calibrated for other colors – so please consider the following test numbers with that in mind.
The 300mW Red emitter is rated by Nitecore at 13 lumens; I measured 12. Nitecore states runtime is 50 hours.
Green is rated at 19 lumens; I measured 21. The green actually seemed brighter than this outdoors, which really shouldn't be too big of a surprise as this is a typical strength of green lights. Nitecore states runtime is 48 hours.
Both red and green matched rated outputs very closely. Blue did not. Nitecore rates Blue at 3 lumens; it registered 48 lumens when I tested it. I can only speculate as to why the numbers are as different as they are, but in practical use Blue is brighter to my eyes than the Green and especially the Red. Nitecore states runtime is 48 hours.
UV is reported to have a wavelength of 365nm, powered at 500mW, with a runtime of 48 hours. While I lack the equipment to verity those numbers, I can report that the UV illuminates the strip in US currency.
It also shows urine and other dried liquids very well. (No pictures will be included; you'll have to trust me.)
The Nitecore Tube UV reports the same wavelength and wattage specifications, though of course a shorter runtime due to the smaller battery. Comparatively speaking, the SRT9 has more throw but an uneven beam due to the reflector inset. The Tube's beam is more consistent and round.
Red, Green, and Blue suffer similar beam shapes due to the way they are inset into the reflector. The beams appear off balance with the hotspot towards one side.
The Police Warning strobe works by alternating red and blue flashes. Red always begins, flashing very quickly over the course of about 7/10ths of a second. Blue then flashes in the same manner before red restarts. The brightness is sufficient for a law enforcement officer to use signaling or announcing presence at night, but higher output would be needed for daytime use or other functions.
All outputs measured:
The battery measured between 2.95V and 2.98V after testing. The over-discharge protection functions well; this is a safe termination voltage and above the battery's protection circuit termination voltage of 2.5V per specifications.
Outdoor Beamshots
All photos taken with a Canon SD4000IS camera. 1/4" exposure, ISO1600, Daylight white balance.
Approximate distances: White deck railing @ 15 ft., white fence in distance @ 75 ft., center of boat @ 100 ft.
Control shot:
UltraLow:
Turbo:
Red:
Green:
Blue
Interface
The SRT9's tail switch is used as the primary on/off switch. If off, the light will not function no matter what position the selector ring is set to. If the ring is on any mode, it will startup in that mode when the tail switch is activated. There is a very small delay when turning on, a "fade in" of sorts.
The center position on the selector ring is standby. In this mode with the tail switch on, the side indicator will flash every 2 seconds to alert you that the light is in standby mode.
While holding the light, turning the ring clockwise from Standby will smoothly progress from Ultralow to Turbo. Turbo is reached with a click and a "notch" felt in hand. Turning the ring further clockwise reaches Strobe. Again, the position is felt in hand.
Turning counterclockwise (anticlockwise) from Standby, the first position reached is UV. Then is Red, Green, Blue, Police strobe, and Beacon in that order.
Total rotation from Beacon to Strobe is just short of one full rotation. There is no marking on the ring that identifies the Standby position alignment, but the long step in notches between Standby and Turbo provides a good way to orient the ring switch position when the light is off.
Problems
No problems were experienced while testing the SRT9.
Commentary
The SRT9 takes the reigns as SRT flagship, bringing new levels of output and runtime to the lineup. With 8 modes, 5 emitters, infinitely variable output up to 2150 lumens, over 250 meters of throw, and a battery indicator, there's not much missing.
As the owner of an EC4SW and SRT7GT, the SRT9 feels like a hybrid of the two. It has the strong and floody output and excellent heat management of the EC4SW as well as the 5 emitters, magnetic ring, and infinite brightness adjustment of the SRT7GT.
It is comfortable in hand or in jacket pocket, though too large for front pocket carry. Proper orientation in hand is always easy due to the shape. The ring is convenient to use and allows quicker adjustment up or down than button-operated lights. The ring interface is very convenient.
I am pleased to see the Turbo output match the rated 2150 lumen rating and that it sustains the output without any aggressive stepdowns.
As for weaknesses, Ultralow could stand to be a little bit lower. The XHP50's temperature is cool, though particularly so only at the outer edges. PWM is present and detectable at low output. Finally, as a matter of safety, I would prefer to see UV further from Standby on the ring.
Overall, the SRT9 is a well-balanced multipurpose light that combines strong output, solid heat management, multiple color emitters, and solid battery life into a light that is easy hold and use. It's a jack of all trades, though master of none.
Meter: Dr. Meter LX1330B
Integrating "sphere": Homebuilt tube-style device calibrated on other known lights and test results. Numbers should be considered relative to each other and my other review figures but accuracy is in no way certified or guaranteed.
Camera: Canon SD4000IS
This light was provided free of charge by Nitecore Store for review.
The SRT9 is the newest model in the SmartRing Tactical (SRT) line. Nitecore SRT series lights offer infinite brightness adjustability via the twist of a magnetic ring near the head of the light while a tail switch controls general on/off.
The SRT9 features a Cree XHP50 emitter outputting 2150 lumens as well as ultraviolet, green, red, and blue emitters for multi-purpose versatility. The SRT9 uses two 18650 or four CR123A batteries. With a die-cast body, the SRT9 manages heat very well and is stronger than many other lights.
Here are the key review details in one table for the TL;DR crowd:
Unboxing
The SRT9 arrived in a retail box within a padded envelope. The box itself is rather compact at 2.75" wide, 7.25" tall, and 2.125" deep.
The SRT9 box is in the same style as other current Nitecore flashlights.
The front has quite a bit of information: model designation, emitter type, battery type, peak output, SmartRing explanation with image, and images showing the various emitters.
The back of the box has verbiage describing the design of the SRT9, its advantages, the multiple outputs and features of the SRT9, disposal safety, registrations, SYSMAX contact information, and a legal disclaimer.
The left side has a (not to scale) image of the SRT9.
The right side of the box promotes Law Enforcement and Search as intended uses for the SRT9. It also shows the key output, impact, and water resistance specifications.
The bottom of the box has a single adhesive label with model information and barcode.
Opening the box, we find the SRT9 in a plastic carrier with the accessories underneath.
Included is a holster, manual, warranty card, spare o-rings, lanyard, and already-attached pocket clip.
The manual is in 9 languages (English, Spanish, German, French, Polish, Japanese, Romanian, Chinese, and I believe Korean); each language's section is complete as the text is quite small.
It can be accessed online here:
http://flashlight.nitecore.com/pdf/SRT9_UM_EN.pdf
Nitecore backs the SRT9 with a 5 year warranty, as advertised on the box as well as in the manual.
Design
The SRT9 is a compact side-by-side 18650 light with a 40mm head. This form factor is shared with the EC4S, EC4SW, and EC4GT, so traffic wands and other accessories are interchangeable between these models.
Necessary to accommodate the tail switch, the SRT9 abandons the thumbscrew used to secure the battery door on the other lights to a new design that clicks to lock the tail cap from both sides using spring-loaded pins that extend from the main tube.
The SRT9 feels more aggressive in hand than the EC4SW thanks to deep cooling fins around the head and down two sides.
Nitecore states the SRT9 is 5.83 in. (148 mm) long with a head diameter of 1.57 in. (40 mm). My measurements confirmed these numbers exactly. Weight without batteries was also verified at 7.9 oz. (224 g).
The SRT9's size can be appreciated when put next to other lights. L to R: ThorFire C8S (18650), Nitecore TM03 (18650), Nitecore EC4SW (18650*2), Nitecore SRT9 (18650*2), Nitecore SRT7GT (18650), Olight R50 Pro (26650), Convoy S2+ (18650), Manker E11 (AA).
The head of the SRT9 has a stainless bezel that is flat in shape and color. There are 5 small indentations machined into the inner part of the bezel. When the SRT9 is placed head-down on a flat surface, no light can escape past the flat bezel – so users should take appropriate care to avoid unintentionally depleting the battery this way.
The glass is AR-coated mineral glass. The reflector is of the orange peel variety; this produces a floody beam that hides the imperfections introduced by the multi-die XHP50 emitter. The reflector was free of visible defects.
The central quad-die Cree XHP50 emitter is perfectly centered. The Green, Red, Blue, and UV emitters are in shallow wells bored into the central reflector.
The Nitecore logo, website, model name, registration, and disposal information are all located on the head of the SRT9. The embossing is clean but the text does blend together from a distance given the thick typeface and compact nature of the printing. This isn't a bad thing; many users prefer to see text as contained as possible.
Just to the side is a HOT logo.
Opposite of the main embossing is the individual light's serial number. It is extremely small and hardly noticeable.
Below the embossing, cooling fins extend around the circumference of the SRT9. These are deeper than on the EC4S, though sections alternate in length to give some style and grip above the magnetic ring.
The magnetic ring switch - the signature feature of the SRT line - has good knurling and channels for grip.
The narrow sides of the battery tube are identical with a checkerboard-style grip.
The flat sides of the battery tube are not the same. While both have cooling fins, one has the battery indicator light while the other side has the pocket clip.
The battery indicator light is small, blue, and flashes every 2 seconds when the light is on standby or when the battery is below 50%. Below about 10%, the indicator light flashes rapidly.
The titanium coated stainless steel pocket clip is attached with Torx ("star drive") screws. The clip is smooth and unobtrusive in hand or in a jacket pocket. It is however difficult to use because of the tail cap arms; these are taller than the clip and obscure access to the clip when trying to slide the SRT9 clip onto a pocket.
The clip is not strong or textured enough to hold onto the brim of a hat (though too heavy to practically use this way anyway). As the SRT9 won't be "front pocket carry" for most people, I found the clip works best when clipped directly to the waist of a pair of pants or a belt. Like this, it holds the SRT9 well. If more strenuous activity is likely, the holster should be used.
The tail has a forward clicky switch that enables momentary on; if the ring has been left in an "on" position and the tail switch is half-pressed, the light will turn on so long as the tail switch is held. The switch boot has a "N" in the pattern and a spare switch boot is included. Pressure required to activate the switch is on the firm side of moderate.
The tail itself – the battery door – attaches via two spring-loaded pins that extend outward from the battery tube into sockets in the arms of the tail cap. These have to be pressed to allow the tail cap to slide into place. A good bit of pressure is then required on the tail to get it to securely clip onto the pins.
Those arms extend rearward past the switch. This allows the SRT9 to tailstand, though only on very flat surfaces. Indoors it should be no problem, but finding appropriately flat surfaces outdoors may be a challenge.
A slot on each side of the tail allows the lanyard to be attached. The holes are large so threading the lanyard is easy The tail-end location keeps using the lanyard from feeling awkward. Given the size of the holes, though, Nitecore could have used a split/dual hole design to keep the lanyard loop to the side instead of over the tail end where it affects tailstanding.
One design feature that I noticed… the arms on the battery door have chevron-shaped lines. A very similar design is on the Nitecore Tube keychain lights.
While laying the Tube next to the SRT9, I inadvertently confirmed that the SRT9's selector ring is magnetic. It attracted the Tube's keyring and was strong enough to hold the weight of the Tube when lifted.
As with many other Nitecore lights, button top batteries are required. The screws on the board in the tail seemed to prevent flat tops or incorrectly inserted batteries from making contact.
The springs are gold colored and there are both inner and outer springs. A custom gasket around the tail cap ensures IPX-8 water resistance to 2 meters underwater. Nitecore includes a spare gasket.
The SRT9's battery tube has channels to hold the batteries in place during loading. These metal sections between the batteries also help to absorb and radiate heat from the light and the batteries.
The holster fits the SRT9 well whether the SRT9 is stored head up or head down. It has a D-ring, belt pass-through loop, and hook-and-loop – so it can be worn a variety of ways.
Before continuing to the performance information, here are a few more pictures of the SRT9 in its natural habitat (outside)!
Performance
The XHP50 LED is a quad-die emitter, which would naturally produce a crosshair in the beam. At a very close distance, this is still visible.
Nitecore uses an orange peel reflector to help remove these artifacts at a normal distance. The resulting beam has a hotspot with soft edges. The corona is wide and transitions smoothly into the spill. The wells for the colored LEDs do not seem to affect the beam at all.
The majority of the beam appears creamy neutral with some cool blue at the outer edges of the spill.
To demonstrate the relative color balance, here is the SRT9 surrouned by lights with emitters of various tints and temperatures.
L to R: Astrolux S41S with neutral 219B, Nitecore C1 with cool XHP35 HD E2, Convoy S2+ with cool XM-L U2 1B, Nitecore SRT9 with cool XHP50, Olight S1R with cool XM-L2, BLF348 with neutral 219B, and Lumintop Tool with warm 219B.
Nitecore rates the SRT9 at 2150 lumens on Turbo. Nitecore used Nitecore 3400mAh button-top protected 18650 batteries for official specifications so I used the same spec Nitecore batteries (model NL189) for my tests. 4xCR123A batteries can be also used. Flat top batteries do not work.
At turn-on, the SRT9 output a solid 2273 lumens. At 30 seconds, I found output at 2153 lumens. This matches the 2150 lumen rating provided by Nitecore exactly.
What didn't match rated specifications was Turbo runtime, though it was a good surprise. Nitecore states runtime at 1 hour; I found output didn't drop to 10% (ANSI FL1 standard) until 2 hours and 20 minutes into the test. While output dropped about 200 lumens in the first 2 minutes, the output was then linear until the batteries were nearly empty. 50% was reached at 68 minutes; 10% was reached at 140 minutes. An 80mm PC fan running to produce some airflow. Ambient temp was 78F.
The SRT9 has Nitecore's "Advanced Temperature Regulation (ATR) module" designed to keep the LED from overheating, yet the light dissipated heat so well that ATR didn't appear to step in at any point during testing. The SRT9 remained cool with head temperature peaking at 120F (49C) 9 minutes into the Turbo test. The die-cast design is very effective at distributing heat.
Nitecore rates the Ultralow mode at 0.1 lumens. The lowest that I could get the SRT9 to produce any light at with a fresh battery was at about 2.7 lumens. No runtime test was conducted; Nitecore rates it at 250 hours.
As most people will use the SRT9 somewhere in-between Turbo and Ultralow, I ran a test with the light at as close to 1000 lumens as I could. At 30 seconds, the SRT9 was outputting 996 lumens. The output climbed on its own, peaking at 1049 lumens at minute 33. It then dropped to 938 lumens by minute 42. That output was maintained until 2:25, at which point a fairly linear drop towards 0 began. 50% of initial output was reached at 3:06 with 10% hit at 3:27.
Both outputs tested, graphed together:
I did detect PWM both with the "mirror test" and via camera when the SRT9 was operating at the low end of its output range. On Ultralow, I could easily observe it on a wall. At high output levels I did not detect it visually so it is either high frequency or non-existent there.
I tested throw distance at 1.46 meters and the resulting candela was 9,810 - equivalent to 289 meters of throw. This outperforms Nitecore's rating of 246 meters (289 yards).
My lumen measurement device has not been calibrated for other colors – so please consider the following test numbers with that in mind.
The 300mW Red emitter is rated by Nitecore at 13 lumens; I measured 12. Nitecore states runtime is 50 hours.
Green is rated at 19 lumens; I measured 21. The green actually seemed brighter than this outdoors, which really shouldn't be too big of a surprise as this is a typical strength of green lights. Nitecore states runtime is 48 hours.
Both red and green matched rated outputs very closely. Blue did not. Nitecore rates Blue at 3 lumens; it registered 48 lumens when I tested it. I can only speculate as to why the numbers are as different as they are, but in practical use Blue is brighter to my eyes than the Green and especially the Red. Nitecore states runtime is 48 hours.
UV is reported to have a wavelength of 365nm, powered at 500mW, with a runtime of 48 hours. While I lack the equipment to verity those numbers, I can report that the UV illuminates the strip in US currency.
It also shows urine and other dried liquids very well. (No pictures will be included; you'll have to trust me.)
The Nitecore Tube UV reports the same wavelength and wattage specifications, though of course a shorter runtime due to the smaller battery. Comparatively speaking, the SRT9 has more throw but an uneven beam due to the reflector inset. The Tube's beam is more consistent and round.
Red, Green, and Blue suffer similar beam shapes due to the way they are inset into the reflector. The beams appear off balance with the hotspot towards one side.
The Police Warning strobe works by alternating red and blue flashes. Red always begins, flashing very quickly over the course of about 7/10ths of a second. Blue then flashes in the same manner before red restarts. The brightness is sufficient for a law enforcement officer to use signaling or announcing presence at night, but higher output would be needed for daytime use or other functions.
All outputs measured:
The battery measured between 2.95V and 2.98V after testing. The over-discharge protection functions well; this is a safe termination voltage and above the battery's protection circuit termination voltage of 2.5V per specifications.
Outdoor Beamshots
All photos taken with a Canon SD4000IS camera. 1/4" exposure, ISO1600, Daylight white balance.
Approximate distances: White deck railing @ 15 ft., white fence in distance @ 75 ft., center of boat @ 100 ft.
Control shot:
UltraLow:
Turbo:
Red:
Green:
Blue
Interface
The SRT9's tail switch is used as the primary on/off switch. If off, the light will not function no matter what position the selector ring is set to. If the ring is on any mode, it will startup in that mode when the tail switch is activated. There is a very small delay when turning on, a "fade in" of sorts.
The center position on the selector ring is standby. In this mode with the tail switch on, the side indicator will flash every 2 seconds to alert you that the light is in standby mode.
While holding the light, turning the ring clockwise from Standby will smoothly progress from Ultralow to Turbo. Turbo is reached with a click and a "notch" felt in hand. Turning the ring further clockwise reaches Strobe. Again, the position is felt in hand.
Turning counterclockwise (anticlockwise) from Standby, the first position reached is UV. Then is Red, Green, Blue, Police strobe, and Beacon in that order.
Total rotation from Beacon to Strobe is just short of one full rotation. There is no marking on the ring that identifies the Standby position alignment, but the long step in notches between Standby and Turbo provides a good way to orient the ring switch position when the light is off.
Problems
No problems were experienced while testing the SRT9.
Commentary
The SRT9 takes the reigns as SRT flagship, bringing new levels of output and runtime to the lineup. With 8 modes, 5 emitters, infinitely variable output up to 2150 lumens, over 250 meters of throw, and a battery indicator, there's not much missing.
As the owner of an EC4SW and SRT7GT, the SRT9 feels like a hybrid of the two. It has the strong and floody output and excellent heat management of the EC4SW as well as the 5 emitters, magnetic ring, and infinite brightness adjustment of the SRT7GT.
It is comfortable in hand or in jacket pocket, though too large for front pocket carry. Proper orientation in hand is always easy due to the shape. The ring is convenient to use and allows quicker adjustment up or down than button-operated lights. The ring interface is very convenient.
I am pleased to see the Turbo output match the rated 2150 lumen rating and that it sustains the output without any aggressive stepdowns.
As for weaknesses, Ultralow could stand to be a little bit lower. The XHP50's temperature is cool, though particularly so only at the outer edges. PWM is present and detectable at low output. Finally, as a matter of safety, I would prefer to see UV further from Standby on the ring.
Overall, the SRT9 is a well-balanced multipurpose light that combines strong output, solid heat management, multiple color emitters, and solid battery life into a light that is easy hold and use. It's a jack of all trades, though master of none.
Meter: Dr. Meter LX1330B
Integrating "sphere": Homebuilt tube-style device calibrated on other known lights and test results. Numbers should be considered relative to each other and my other review figures but accuracy is in no way certified or guaranteed.
Camera: Canon SD4000IS
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