My review of The Fenix TK 51 hand held

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My review of The Fenix TK 51 hand held

Postby Cody JW » Nov 24, 2013 8:43 pm

Fenix TK 51 by Jeff Cody


Fenix has just introduced one of its newest flashlights . The TK 51 allows the use of spot or flood or both spot and flood. The maximum output is listed at 1800 Lumen when using both at once. Flood is 900 Lumen and spot is also 900 lumen on its max setting. Each has 4 output settings and also features an 1800 lumen strobe. This light uses Cree XM-L 2 Leds . Lifespan for these LEDs are 50,000 hours. The light is approximately 7.5 inches long and around 2 inches in diameter in the tube and slightly larger at the head. Weight is listed at 430 grams without batteries. This light can operate off several battery types. Fenix recommends using their ARB-L2 18650 , other 18650 can be used. This light can also operate off 2,4 or 6 CR 123 Lithium and also can operate off 16340 3.7 V and 16340 3.2 V . This light can operate off 1, 2 or 3 18650 Lithium Ion.3 buttons control the light, one for spot another for flood and a third power button. If you press and hold spot or flood button for one second it will activate the 1800 Lumen strobe until either button is released. Press and hold the power button for one second for instant 1800 lumen spot and flood until the power button is released. This light will remember the last brightness level and will go to that level the next time the light is on. When batteries run down the light will switch down to reduce output level until batteries are replaced or re charged. This light also has overheat protection when in the turbo mode to where it will drop to high when it detects high temperature and will stay at that mode until temperature drops to a safe level.

Caution should be used when using 18650 Litium Ion batteries . When using this or any device that uses multiple 18650 it is important to use matching batteries that are all in the same state of charge. Fenix recommends the ARB-L2 or similar protected batteries with circuit protection that can reduce the risk of combustion. Smart chargers are recommended to charge Lithium Ion. Fenix recommends 3.2 Volt 18650 or 3.2 volt 16340. 3.7 volt batteries can be used but they suggest using with caution and understanding risks associated with the use of unprotected cells. All output listings claimed by Fenix are using their ARB-L2 18650 battery. The use of other batteries and use in certain extreme environments can affect output and run times. The Fenix warranty replaces products within 15 days of purchase and repair products free of charge within 24 months of purchase and after 24 months they will charge for replacement parts if the light is used within warranty parameters.

The specs for this light are each LED has a turbo setting at 900 Lumen a high setting at 400 a mid at 150 and a low at 10. Strobe is 1800 Lumen. Listed run times are between three and one half hours on the high with three 18650s to 420 hours on the low. If both LEDs are used at once then cut those run times in half. The beam distance is listed at 425 meters. Impact resistance is a drop of 1 meter and this light is IPX 8 rated meaning that it has been tested for submersion in 2 meters of water for 30 minutes. The light is constructed of aircraft grade aluminum and is anodized with an anti abrasive finish. It features a toughened ultra clear glass lens with anti reflective coating. Reverse polarity protection guards from improper battery installation. You simply unscrew the head to open up the light and the battery case drops out.. The light comes with a lanyard and an extra O ring. If this light is taken into a cave environment I would suggest checking and cleaning the O ring of any grit on a regular basis to ensure the waterproof rating. Fenix also recommends removing batteries for long term storage.

I received my TK 51 in early November as I was selected to be part of the Fenix global test campaign for this light. In fact mine has “Global Testing Campaign” stamped on the side of it. The first thing I noticed was how solid this felt in my hands. I was not too surprised of this as I own other Fenix hand held lights that have the similar feel. I loaded mine with 3 Panasonic 3400 18650 batteries. I ran through the options and was very impressed. The throw on the spot was impressive. The controls were easy to use. I had to compare this to my El Speleo 2000 cave specific headlamp as that is the only thing I own of similar output as The TK 51. I have to say at this point that El Speleo is a purpose built lamp made with certain optics specific to what the manufacturer feels is the need of a caver. The TK 51 has a deeper and larger reflector that I suspect helps with the throw of the spot. I took photo's of this comparison at night in my backyard. The throw of The TK 51 was much further and a brighter white pin point hot spot compared to the wide angle spot on the 1000 Lumen El Speleo. Like the TK 51 ,the El Speleo runs off 3 18650 Lithium Ion batteries. The El did a better job of lighting up the area between myself and where the lights were pointed when doing the spot comparisons , this can be a plus when negotiating your way in a cave environment. The Fenix did look much brighter because the output is focused to a narrow area compared to a wider angle spot . Personally, it would be nice to have both types of spot on one cave lamp but I understand that may not be possible to have two spots and a flood and still keep the size manageable. The wide spot on The El will light up the area of a good size underground room without any of the “tunnel vision” you can get with a narrow spot but the narrow spot will light a specific object far away much better. It kind of depends on the type of caving you do and what your preferred optic is. The TK 51 may be a bit large to carry in a cave pack unless you are in a specific situation like a deep pit or very large passage .

The flood comparison I feel was advantage El Speleo. The TK 51 produced a more circular type light where The El Speleo lit up everything all around you including your feet without having to look down at your feet. I had to point the TK 51 down toward my feet a bit and not straight out to get what I feel is a comfortable amount of light at my feet. This comparison illustrates what cave specific optics are. I find that when inside a cave moving over breakdown piles that it is an advantage to see around your feet well when pointing the light forward. You are not pointing the light forward then down many times. You can move more efficiently keeping your lamp pointing forward the whole time. I have to note that many Fenix products are multi purpose sport lights and are not designed for the specific purpose of caving. Also I would like to point out that the TK 51 will cost around 150.00 US Dollars and The El Speleo cost a bit over 400 US Dollars so from that standpoint my comparison may be an apples to oranges comparison. With the understanding of what the TK 51 is designed for I have to say I am impressed with it even though as a caver I have a bias for cave specific optics. The idea of a hand held light with dual optics impresses me. I also compared the spot on The TK 51 to the spot on my Fenix 4AA 520 Lumen LD 41. Not surprised that TK 51 was brighter but I am impressed with the output on The LD 41 for a light that runs off 4 AA s. All in all the TK 51 is a very impressive light and has its purpose, even in a cave.
It only takes one person to surrender a dog to a kill shelter ,but it takes many to rescue it.
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Cody JW
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Name: Jeff Cody
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