Princeton Tec EOS 70PT EOS - 2004-2011 and, probably, several years more will remain with us. Not known too much in the European market; in the US market, adored for years for its simplicity, reliability, water tightness and current stabilisation. For the biggest competitor in the market, the Petzl company, this took as much as 7 years. What special is in EOS, that makes it so unique and extraordinary solution?


Review of the Princeton Tec EOS 70 headlamp...


Some marketing data.

One of Princeton Tec’s most popular headlamps, the durable EOS is an outdoorsman’s dream come true. With a single long-throw maxbright LED encased in a rugged, molecular bonded, watertight housing, the EOS is up to any challenge that a trail, work site, slope, or stream will throw at you. Four output modes (high, medium, low, and flash) allow the EOS to keep its regulated brightness while the batteries remain at optimum levels. The EOS is also available in the following models: EOS Tactical, EOS II, EOS Industrial, and EOS Bike.

Light output : 70 lumens

Led : Maxbright LED

Burn time : up to 121 hours - High 1h, Mid 10h, Low 50h

Power supply : 3 AAA batteries; alkali or lithium type

Water tightness : IPX7 (this means that you can swim but not too long).

Weight : 104g including batteries

Colours: black, orange, blue, olive

In addition, some UL standards :
Class I Division 2 Groups A, B, C & D Class II Division 2 Groups F & G

Info what is this :

Simply, this means admissions to work at places that may include, temporarily, volatile, inflammable vapours, gases, and dusts; an equivalent of the European ATEX, but in the standard not special version as it is with the Tikka XP

Price : 30-49$


Somewhat bigger and more heavy than the popular Tikka XP (10g difference), much bigger control button. No edges, unnecessary mechanical components nor decorations. On the casing, description of the Hazloc admissions, on the front, the information about the number of modes, water tightness and regulated light.

Screw closure – simple and effective – the screw is big enough to be undone without any problem; after tightening, you can be sure that the casing is sealed. The button rubber is glued into the casing, just as the glass shielding the optics.

The system of positioning in the head, in the 70-lumen version for 2011 is based on 3 meshes (a change with respect to the earlier 50-lumen-version); you’d have to play with it quite a long to destroy or wear it up.

You can see the rubber gasket along the full periphery; the parts are interconnected with a steel mandrel so that this component will hardly undergo wear. The batteries may be put in and taken off easily, without use of additional tools.

What’s whining inside ?

The lamp is constructed without use of tiny screws so that, in order to get inside, you have to bore delicately the melted pins holding the battery container. After this operation, remove the whole module with the battery container, led and optics.

The 70-lumen version is based on the Luxeon Rebel LED. There is a little buzz about it since somewhat for ever, the PrincetonTec company states that they apply Maxbright LEDs, but it has also a simple explanation. Due to the modular construction, they may replace the old optics by a new one and launch into the market a stronger version of their headlamp; it was so in the case of changing over from EOS 50 to EOS70. From the above, it follows a part of its popularity among the moders; you can put into it everything that can fit inside and it will still operate as needed.

Power supply.

EOS jis a regulated headlamp what means that, for some time, the level of emitted light / supply current remains constant. The system is based on 3 transistors operated by the IC sealed with epoxy; if somebody wished to change the current value for a given mode, it could be done by changing the control resistors next to the transistors ;). Thus, independently of if alkali, lithium or rechargeable NiMH battery is applied, you’ll get the same amount of light. Till the instant that the energy source is not capable of delivering adequate current, the controller switches over to the weaker mode.

The measurement results for new alkali and rechargeable batteries NiMH confirm the manufacturer’s statement.

PrincetonTec EOS 70 – 3xAAA batteries
V-In     I-in    P-In       V-led    I-led   P-led   Eff.
High    3,85V  256,28mA  0,987W     2,97V  304,32mA  0,903W  91,5%
mid     4,35V   75,63mA  0,329W     2,84V  102,86mA  0,292W  88,7%
low     4,53V   23,03mA  0,104W     2,74V   26,38mA  0,072W  69,4%
PrincetonTec EOS 70 – 3xAAA rechargeable batteries NimH
V-In     I-in    P-In       V-led    I-led   P-led   Eff.
High    4,17V  255,39mA  1,065W     2,97V  299,74mA  0,890W  83,6%
mid     4,26V   77,31mA  0,329W     2,84V  100,64mA  0,286W  86,8%
low     4,29V   22,84mA  0,098W     2,73V   25,18mA  0,069W  70,2%

Many users had only one wish for PrincetonTec – that they make a version for 2xAA :), but, this was made, at last, Petzl, in the model Pixa 2. The times of operation in the highest mode (times of a transition to the weaker mode ) for alkali batteries highly exceeds the declared value: 1 h -> realistically ca. 2h and up to 3h on rechargeable batteries.

How does it light ?

In conformity with the specification, let me say so :).

Princeton Tec EOS 70 vs Princeton Tec EOS 50 - high

It was quite a difference in color tints of the Luxeon leds - thats why there is such a difference.

Princeton Tec EOS 70 vs Black Diamod Spot 2011 – high

For those who will be seduced by the result of Spot 2011 recall that shines just so strongly on the batteries, and only the first 30 minutes ;).

Princeton Tec EOS 70 vs Petzl Tikka 2 XP - high

Pozostałe 2 tryby dla EOS’a – Mid i Low


The lightweight, durable, waterproof, regulated, easy for self dependent modifications (just after the test, I’ve put into it Cree XP-G => I’ve made EOS 110 + optics 25* since it is the best opting for traipsing in bushes / holes (in my opinion).