[candle lamp]

TR51 is single XM-L U2, dual switch interface, and high-output light from Rofis.
The hard cardboard box has a magnetic closing flap, cut-out foam holding the light and extras. TR51 comes with user manual, lanyard, spare o-ring & tailcap rubber boot, and nylon belt-holster.
.
.
Manufacturer Specifications from Rofis website & user manual :
• Cree XM-L LED (U2)
• Battery : 4xCR123A, 2x18650, 4x16340 (16340 battery is not recommended)
• 152 mm(length) x 45 mm(body width) x 46 mm(head diameter)
• 233-gram weight (excluding batteries)
• Digitally regulated output - maintains constant brightness
• Intelligent memory circuit, automatically memorizes the brightness level when switch off
• Over-discharge protection function, when the battery is in low voltage, the light will flicker twice every two minutes
• Reverse polarity protection, to protect from improper battery installation
• Adopts the double-tube design with knurling, comfortable to hold, convenient for operation
• Two mode groups and seven types of output
• Capable of standing up securely on a flat surface to serve as a candle
• Adopt double-switch design (tail tactical switch, side dimmer switch)
• 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 (tested in lab by using quality CR123A primary Lithium batteries) are approximate and may vary between flashlights, batteries, and environments.


.
.



The hard(type III) anodizing is a matte black and no flaws on my sample. There are identification labels on the head only. All labels (i.e., manufacturer name, logo on one side and caution for hot surface, URL, serial number on the opposite side) on the head are clear and bold in bright white against the black background. There are two switches at both head and tailcap. The light has two separate battery tubes side by side, but they are combined into one on both head and tailcap.
.
.


The light features a bezel and a tailcap retaining ring (scalloped on both bezel and tailcap). The head has cylindrical design with dodecagonal shape on the neck (i.e., right on the side button switch) which provides anti-roll feature.
.
.


The light has 2 parts (i.e., head and battery tube). It's interesting the cooling fins are on the upper side of the battery tube.
.
.


The TR51 comes with a slightly large & relatively deep smooth reflector, and use a cool white XM-L U2 emitter. Centering of the emitter is perfect 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 TR51 is on when stood on its head (i.e., bezel down).
.
.


Here are some close-up shots of the cooling fins and side button. The side button protrudes slightly from the head surface, and is comfortably placed there where the thumb should rest. Activation and output level changing is smooth and easy.
.
.



The positive & negative sign labels on the upper part of the battery tube shows you the correct orientation of the batteries. So you can insert the batteries as shown in the picture. Rofis claims the light has a reverse polarity protection function and over-discharge protection function built-in.
.
.


On the back side of the head, you will see there is a notch, or protruded area of the green circular board. This corresponds to the groove visible on the battery tube (i.e., the notch on the head locks into this groove during tightening the head or battery tube). There are two small raised positive & negative-contact points on the board, which all are linked to the negative & positive-contact spring in the base of the battery tube. The 2x18650 or 4x(R)CR123A are run in series (i.e., 2S or 4S).
.
.


It's easy for you to line up the notch with the groove by just turning or tightening the battery tube. The spring-loaded board in the head doesn't rotates on an axis together with the battery tube initially (i.e., the battery tube rotates only). If the notch lock into the groove at a certain turning point of the battery tube, the board in the head starts turning in sync with the battery tube. (You can feel and hear a slight collision between the notch and groove when they interlock.) The spring-loaded board in the head is movable upward about 2mm.
.
.


There are contact springs in the battery tube.
Thanks to the raised contact points on the spring-loaded board in the head and the contact springs in the battery tube, both flat-top and button-top cells has an wide range of the lengths seem to work in the light. I will explain it later on again.
.
.


The light lacks knurling as such, but there are a large number of concentric ring ridges and some shallow transversal grooves along the battery tubes. This pattern adds to the enhanced grip.
.
.


Both male and female screw threads are fully anodized. There are also a reasonable number of threads, 8 full turns. The o-ring is a bit thick. I can screw the battery tube through seven and a half full turns for complete tightening the TR51 with protected 18650's installed in practice, and turn the light on. But with the light on, I have to loosen the battery tube more than six and a quarter full turns for turning it off. This is because the spring-loaded board in the head and the spring contact in the battery tube still have a certain compression. Once there is no compression on the springs, the notch & the groove unlock into position. (i.e., there is no lock-out to speak of in the light.)
.
.


Screw threads are high quality square-cut. They are smooth with no cross-threading or squeaking on my sample.
The overall build quality seems excellent.
.
.


There are four small holes on the tail lip for lanyard attachment. You need to unscrew the two cross recess bolts to replace the switch rubber boot. The forward clicky switch has a good feel but slightly stiff.
.
.


The light can tailstand perfectly with a lanyard attachment.
.
.
User Interface
Turn on-off by the tailcap forward clicky switch (press-on for momentary, click for locked on).

There are two modes (i.e., general mode & flashing mode).
On-off is controlled by the tailcap switch and output mode switching is controlled by the side button on the head.

1) General mode
Output changing is controlled by the electronic side button switch. Click and release to advance through outputs, 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).
Note that you cannot set the output level while the light is off. The electronic switch only works when the light is powered on by the tail switch first. As such, there is no standby current on the TR51.

2) Flashing mode
The “hidden” Strobe, SOS, Frequent Flashing are accessed by clicking and holding the side button switch for more than 1 sec. The light will move between Strobe, SOS and frequent flashing when you click and release the side button. To return to the general mode, hold the side button for more than 1 sec again.
The flashing mode has no memory.
.
.


From left to right, VicLite 18650 protected, Rofis TR51, Skilhunt DT-20, Skilhunt Defier X3, Xtar TZ58.
.
.


Same lights which use 2x18650 batteries.
.
.


The light is good size to hold, and it's smaller than I expected. Overall and construction feels solid. The overall gripability seems reasonable, but can be more slippery than most in this class due to lack of real knurling on the body.
.
.


All 16340 cells such as CR123A and RCR123A fit fine in the battery tube and just work fine. (i.e., there is enough clearance in the battery tube to accomodate the diameter of all 16340 cells.) The unprotected 18650 cells fit in the tube and do activate in the light without any problem as well. While some of the wide protected 18650's don't fit in the tube (i.e., a bit snug) or don't go down. My measured inside diameter of the tube is 18.58mm. I don't experience the issue with 18650 cells which diameter is equal to or less than about 18.5mm.

Rofis confirms the low battery voltage flickering is about 5.4v - this feature is available for 2x18650's and 4xCR123A's, but not 4xRCR123A's - the light will drain the batteries before it automatically turn off. So if there is flickering, you can change the batteries soon. I saw the light flicker twice every two minutes as claims when using 2xCR123A's, but couldn't see the flickering indication when using 2x18650's protected due to the higher protecting voltage (i.e., 2.8v) than the light. The light was just turned off because the protection circuit of my 18650's protected kicked in.
.
.


I found the wrapper around the negative (-) contact on my 18650 protected was peeled off just while tightening the battery tube. It should seem that the wrapper caught on the negative contact point on the board when initial screwing the battery tube about one or two full turns. I think the main reasons are as follows:
1) The negative contact spring is a bit longer than the positive one in the battery tube.
2) The more vertical & horizontal forces are applied to the negative contact than the positive contact on 18650 protected due to the height difference of the springs like above 1). The wider & longer batteries are, the greater these forces become.
3) Both positive & negative contact points on the board of the head have the very sharp edge.
4) The wrapper of some old batteries become a bit loose.

I'd like to suggest Rofis to consider the followings:
1) To make the gradual chamfered edge or fillet curved edge on the sharp raised contact points on the board.
2) To make the positive contact spring a bit higher than the negative one in the battery tube. (otherwise, set them at the same height.)

[Edit : 2012.07.17] I've exchanged e-mail with Rofis, and they know the tearing wrapper is the occasional case for only a few TR51. They will resolve it absolutely in the next batch. [Edit : 2012.07.17]
.
.


The net weight of the light is 242g. The weight including CR123A's and 18650's are 307g and 337g respectively.
.
.


The TR51 comes with a basic nylon holster with a velcro strap on the head. The light fits in the holster head-up only.
.
.
PWM


The light shows no sign of PWM at any output levels. I 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



TR51 steps down on turbo output after 14 mins runtime, on both 2x18650's and 4xCR123A's as well. This seems to be a timed drop-down, not a thermal sensor feature.
If you need the turbo output continuously, click the side button switch 4 times every 14 mins in the next run. The above runtime labelled as "Trubo-Acc." is an accumulated runtime for turbo output. It's interesting High is not brighter than step-down level of Turbo.
Regulation is maintained very nicely through Turbo & High on all batteries.
.
.
Beamshot
1. White door beamshot (about 50cm from the white door)
- ISO100, F/3.2, 1/125sec, Auto white balance



The beam tint on TR51 is cool white leaning very slightly towards the color spectrum green hue around the hot spot, but not by much. There is soft irregular corona surrounding hot spot. The overall beam quality is good.
.
.
2. Indoor beamshot (about 7m from the target)
- ISO100, F/2.8, 1/3sec, Auto white balance



Control shot
.
.


Turbo output
.
.


High output
.
.


Med. output
.
.


Low output
.
.

.
.
3. 55m Outdoor Beamshot
- ISO100, F/2.8, 1/3sec, Auto white balance



Control shot
.
.


Turbo output
.
.


High output
.
.

.
.
4. 60~65m Outdoor Beamshot
- ISO100, F/2.8, 1sec, Auto white balance



Control shot
.
.


Turbo output
.
.


High output
.
.

.
.
5. 130m Outdoor Beamshot (far more than 130m from the target)
- ISO100, F/2.8, 1sec, Auto white balance

[candle lamp]

[Edit] I've exchanged e-mail with Rofis, and they know the tearing wrapper is the occasional case for only a few TR51. They will resolve it absolutely in the next batch. This is good new!

[Tweaker]

One more light from Porsche Design, the original around here.