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Princeton Tec EOS

in Lights - Flashlights & Headlamps

Average Rating
4.79 / 5 (14 reviews)

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kevin davidson
( kdesign )

Mythical State of Jefferson
Princeton Tec EOS on 08/14/2005 12:47:37 MDT Report Post Print

Rating: 5 / 5

Da bomb of LED headlamps--this uses regulated 1 Watt Luxeon LED technology. Bright enough for serious trail illumination, it's simple 3 way plus flash interface will allow throttling down for inside the tent duty and to extend battery life. You will only rarely need to use this at brightest output. A comfortable headband harness and a tiltable cradle complete the package. Weighs only marginally more than the Tikkas and Auroras (3.7 to 2.9 oz., less w/ lithium AAA cells(recommended).

A very deserved 4.9 ( low level could be diffused a little bit for more comfortable reading , no problems though for any post literate types out there).

This was the 1st 5 star rated Headlamp of any type (LED or Halogen) on the wonderful site.

In it's "class", the only real competitors are the BD Xenix IQ,which is almost 2 ounces heavier due to it's seperate batt. pack, and the Petzl Tikka XP,the only failing (a big one) is that it is unregulated. When and if Petzl corrects this, the EOS will be in a real race,indeed.

Edited by kdesign on 08/15/2005 09:49:44 MDT.

Price comparison from GearBuyer:
Petzl TIKKA XP priced at: $43.99 - $54.95
Princeton Tec EOS priced at: $33.74 - $44.99
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paul johnson
( pj )

LazyBoy in my Den - miss the forest
PT EOS on 08/14/2005 16:02:47 MDT Report Post Print

Rating: 4 / 5

i would classify this headlamp as a "low-end" luxeon-type headlamp. by low-end, i mean a smaller, lighter headlamp, running on AAA batts, generally lacking, or not requiring an over-the-head strap since the headlamp is also physically small and light. While much more powerful than earlier small headlamps employing only 5mm LEDs, it is still smaller and lighter than Luxeon-type headlamps running on AA batts. I would not compare this headlamp to some of the latest 1W and 3W Luxeon-type LED headlamps running on 3 or 4 AA batts. These units are larger, heavier, somewhat more expensive, and a bit more powerful, and as such should comprise a separate class of headlamps for the purposes of rating - IMHO.

I would echo all of the positive comments of the original poster/creator of this Review Thread.

The EOS provides plenty of light output on hi for rapid nighttime orienteering even over uneven terrain or on indistinct leaf covered trails. The main drawback to this mode is the very short regulated batt life - but, what can one expect from just three AAA batts. The good news is that after a mere approx. two hrs of regulated output the EOS will "auto-magically" switch to unregulated output to extend the "burn" time from the weakening batts. While this does not make batt life on the maximum/high output setting exemplary, it does make it adequate.

However, even more good news, is that, in most cases, the EOS is so powerful, that use of HI/maximum output is not necessary. Even on Medium output, the EOS produces so much light that nighttime orienteering is easily "doable". In an emergency, the EOS with fresh batts could be used on Medium setting continuously for most of the night (before the light output becomes too weak to really see any great distance) to get one out of a difficult situation should the need arise. In a pinch, even LO/minimum output can be used to slowly walk a distinct trail.

On high, it was quite easy to see blazes on trees 50' to 60' away. On medium, blazes were visible 30' away. Of course, when the batteries begin to drain and the EOS is operating in unregulated mode, then distance viewing begins to degrade. I consider 30' the minimum distance I prefer to be able to see ahead in order to rapidly traverse a trail in the dark. This gives me plenty of time, when on unfamiliar trails, to examine each of the upcoming trees for "blazes", indicating an abrupt turn/bend in the trail, even when moving relatively quickly At 5mph one is traveling ~7.3 fps, & so one has ~4seconds to spot a blaze if one can only see 30' ahead. I also feel that the beam pattern of the EOS requires this. Keep in mind that more head turning is req'd to spot/"pick out" a blaze amongst many trees as one gets closer to it. This is most of my logic behind my arbitrary 30' requirement.

When the batts are fresh, the EOS is a bit bright, even on low, for use as a task/proximity light.

Better battery life would be, perhaps, the best way to improve the EOS performance . Since, electronics already exist in the EOS to regulate the current driving LED, then for a small size/wt gain (~0.4oz for alkaline & ~0.27oz for Li) a fourth AAA batt could be used. I know that this would make the EOS a tad heavier, but for some the increased "burn" time would be welcome. This would especially have a very positive effect on the length of time the EOS operates as a constant output regulated headlamp. That is, the extra voltage provided by the fourth batt would allow the total voltage to remain high enough above the threshold req'd to operate the voltage regulation circuitry. Since Even more sophisticated electronics could allow the system to recognize low voltage, as the batts drain, and switch to a "step-up" mode of operation. The net effect of this would be to extend slightly the regulated output time, and would operate the EOS with decreasing output for a somewhat longer period of time. A slight wt. gain would again be a side-effect of the added electronics. Based upon experience, this voltage "step-up" type of circuit might increase by a couple of hours, to a few hours at most, the "burn" time.

A second improvement would be an integrated diffuser lens to facilitate use as a task/proximity light. However, for a mere ~0.2oz a Photon Microlight can be carried, making this "improvement" less compelling.

As much as I like the EOS, in actuality since the advent of the Tikka XP, a slightly better headlamp - IMHO, I would lower the rating of the EOS slightly to perhaps around 4.5 or 4.75. The Tikka XP would get somewhere about a 4.8 by my way of thinking. That said my experience with the Tikka XP, at this point in time, is somewhat limited, so this is only my initial impression of the Tikka XP. I feel that this initial impression will either be confirmed or drop.

The 4 rating is based upon it's TOO NARROW (too small a diameter) beam, forcing one to bob one's head about like a chicken to focus the beam on rocks & trees in order to spot blazes. Other than this 'crab', it's about perfect.

Link to a Post which contains additional info

Edited by pj on 02/03/2007 04:46:33 MST.

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( sdurgo1 )
compact/water resistant/foolproof on 08/15/2005 09:44:47 MDT Report Post Print

Rating: 5 / 5

I used the PT Eos on night climbs in Ecuador January 2005. We summited, Cayambe 18997 ft,. and Cotopaxi 19347 ft. The low beam was sufficient for sections of plodding and the high beam was great for crevasse and ladder crossings! I put a PT "Pilot" on the headband for a back-up. Great combo. Never changed batteries the whole 2 weeks. The Eos worked right through being coated with rime ice and then dripping with melt water on the way down. I used Lithium batteries.

Mike Barney
( eaglemb )

AZ, the Great Southwest!
Princeton Tec EOS on 11/01/2006 20:55:29 MST Report Post Print

Rating: 5 / 5

I have more lights and headlamps than I'd like to publically admit (solid double digits). This is an excellent headlamp, with 4 lighting modes: Really Bright, Bright, and Battery Saving good for almost anything you personally need. The 4th mode is an unmistakable flashing beacon, which is annoying close up, but very easy to spot at long distance.
I used this for 12 days with 1 set of Lithium batteries, and it worked very well.

What I liked:
Easy on batteries
REALLY Bright mode illuminates an entire campsite of > 10 tents(if it's long and somewhat narrow)
Reasonably priced, often for sale $25- $30

What could be improved: A difuser option.
It would be nice to have a difuser to provide a wider beamwidth. I addressed this by putting a piece of frosted "scotch" transparent tape over the front, and that spread the beam out a little.
If I had to keep only 1 headlamp, this would be it.

Ryan Jordan
( ryan - BPL STAFF - M )

Greater Yellowstone
Princeton Tec EOS Hard to Beat on 11/01/2006 23:30:58 MST Report Post Print

Rating: 5 / 5

Few headlights really jazz me up. This is one of them.

Even though it's now more than a year old, its ruggedness, light quality, and battery miserness remains outstanding.

It's also really easy to use, even with gloves on.

I can't think of anything to improve on this light, honestly.

Except, oh yeah,

Maybe it could be lighter!!

Seriously, though, put some LiAA's in this and you have a great lightweight and powerful light for night hiking and alpine climbing. In spite of all the newer headlamps coming on the market from Petzl and BD, I always find myself going back to the PT Eos.

Douglas Hus
( Hustler )

Ontario, Canada
the one on 01/31/2007 12:42:34 MST Report Post Print

Rating: 5 / 5

Princeton Tec EOS

A capable light that can defend against all sorts of marauding critters, aggressive roots and eye poking branches.

Plus it blows away my buddies (more expensive) light saber.

When they want to see what is on the other side of the lake, they reach for my EOS.

Let the light shine on, baby.

All the best,


Price comparison from GearBuyer: Princeton Tec EOS priced at: $33.74 - $44.99
Mark Verber
( verber )

San Francisco Bay Area
Great navigation light on 02/03/2007 01:49:02 MST Report Post Print

Rating: 4 / 5

This is about the current generation Rebel LED based EOS. It has a new lens which gives a bit more spill, while preserving pretty good throw. It's also twice as bright as the original EOS with the same battery life.

The EOS has a bright, focus beam with a good throw but enough spill to be useful around camp. Waterproof to 1 meter. Mine has been in the rain a number of nights and dropped into a puddle at least once without any ill effects (from the drop or the water).

The button is easy to use, even when wearing gloves. The EOS is light-weight enough that the headband is comfortable even without a top band. The light has 90 degrees of motion, so it's easy to adjust for a useful angle, though my first light was too lose and had trouble staying in the position I put it in with no way to make the mechanism stiffer.

It uses three AAA which is a mixed blessing: shorter batteries life than if AA were used, but it's smaller and lighter. Thanks to decent regulation it keeps it's brightness fairly well, and will work with Lithium batteries. The low intensity mode is bright enough for many tasks will be very economical on battery life (almost factor of 10x less bright than full one).

At one time I rated this lights a 5 because it was the best of the options. today, there are a number of alternatives which are as good or better such as the ZebraLight H51, so I have dropped my rating to 4.

Edited by verber on 01/01/2011 09:59:52 MST.

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evan parsons
( freestyleparsons )

Dowtown LA
LOVE IT on 02/23/2007 23:42:40 MST Report Post Print

Rating: 5 / 5



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Shawn Basil
( Bearpaw )

Another big fan on 02/24/2007 15:53:19 MST Report Post Print

Rating: 5 / 5

For years I used my Tikka and Tikka Plus, exuberantly satisfied with the compact, lightweight, and long-lasting nature of their light. But at times, I found that when I really needed extra light, such as night-hiking or checking out a strange noise in my campsite, my Tikka's beam seemed quite wanting. I would change my batteries the next day and that night discover dramatically more power. I would think that it hadn't been more than 30 or 40 hours of use time since my last battery change. Why did the beam get so low when fresh AAA's were supposed to last 150 hours?

Then I heard about the Princeton Tech EOS and learned about the importance of a regulated beam. This, combined with the ability to use lithium batteries (which Petzl says is not safe with their headlamps), makes the PT EOS as clear winner for me. Some have said that the shorter battery life is a concern for them, but I often found I had to use new batteries at comparable lifestyles with the Tikka to get the performance I needed. The intense main beam has helped in discouraging marmots and skunks from raiding my foodbag. And the reliably bright light from a reasonably light package has my thumbs up.

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Kevin Clayton
( kclayton )

Greater Yellowstone
Excellent on 09/26/2007 20:34:07 MDT Report Post Print

Rating: 5 / 5

This Headlamp has been the best that I have owned.
At first I was skeptical of how it would hold on my head with out a top strap but I have never had a problem with it. The battery life is also amazing. I went a full summer working on a trail crew and never even thought about changing the batteries.

Kevin Egelhoff
( kegelhoff )

Southern Cal
Awesome light !! on 10/07/2008 16:07:39 MDT Report Post Print

Rating: 5 / 5

I have tried four different lights over the last four years and this light is by far my new favorite. I can't see any reason to change lights for a while now. Other reviews are spot on and I had better light and longer battery life then all four other people over the 9 day hike I just did. To top it off, everyone turned off their lights to conserve power and typically relied on MINE most of the time for their lighting needs and mine still lasted longer and was just as bright on day nine.

Edited by kegelhoff on 10/07/2008 16:08:22 MDT.

Keith Selbo
( herman666 - M )

Northern Virginia
Not great, but I haven't found anyting better on 10/15/2009 11:40:55 MDT Report Post Print

Rating: 4 / 5

A little heavy, but not uncomfortably so. The long lasting low beam (121 hrs on 3 AAA's) is usually all I need for hiking and almost every task in camp.

The high beam punches a deep hole in the darkness when you need it. That's especially nice when you're looking for the next blaze and the trail isn't well defined and the blazes are far apart.

I always hike with the low beam, momentarily activating the high if I can't see the next blaze. The high beam can iluminate a white blaze 200 or more feet away.

The functions are selected by multiple pressings of the switch. One press for high beam, two for medium, three for low, and four for emergency flash mode. If you haven't pressed the switch for two seconds, the next press turns the lamp off.

The lamp pivots up and down on a shaft so you can aim the beam from straight ahead to straight down or any point in between. The tight beam of the EOS makes this a necessary feature. Straight ahead for hiking, part way down for working at a table and almost all the way down for reading while lying down.

One reviewer opined that it would be worth the extra weight to have more battery capacity. If so, I suggest just carrying a spare set of batteries to double the burn time.

In less sophisticated headlamps, it can be difficult to assess the condition of the batteries because the dimming takes place gradually as the batteries deplete. The fact that the EOS is regulated makes it easy to judge battery condition. When there is no difference between high and medium, you've reached the first level of depletion. When there's no difference between medium and low, you can start thinking about replacing the batteries.

If you've ever dropped a cheap headlamp in a stream, you'll appreciate the water tight enclosure of the EOS.

So why the 4 rating for such a well engineered product with great human factors? Mostly because the ratings won't let me select a 4.5 which is what I would give the EOS because they didn't include a diffuser. The focused beam is ideal on the trail, but when I'm working in camp, making continuous adjustments of the angle of the lamp to keep it on my work is tedious. A flip in diffuser would be most welcome. It's not like this isn't a new idea. Princeton Tec makes a tactical version of the EOS that has drop in colored filters. At the very least, they could offer a drop in diffuser for that but they don't.

I think this is the best headlamp out there for the price and for what I want to use it for. I'll never buy another until they offer it with a diffuser.

Edited by herman666 on 10/15/2009 11:46:43 MDT.

Price comparison from GearBuyer: Princeton Tec EOS priced at: $33.74 - $44.99
Matthew Swierkowski
( Berserker )

TEC EOS on 03/02/2010 10:52:20 MST Report Post Print

Rating: 5 / 5

I’ve been using this headlamp (both the original and newer version) for years. The reviewers above pretty much covered everything with this headlamp, so I am not going to repeat all that. It’s light weight, bright and water tight…what else do you need.

One thing I will comment on is the difference between the original version and the newer version. The original version throws a tight fairly white (with slightly blue tint) beam of light, while the newer version throws a wider yet brighter off white (slightly yellowish) beam of light. I really like the newer version from the standpoint that it is brighter if trying to look deep into the woods (like for a marauding bear or something) or hiking at night, and it lights up more area. Other than that they are pretty similar.

One user above commented on using lithium batteries successfully in this headlamp. I haven’t been as successful. They work fine, but the issue is the burn time. They seem to loose their juice way too prematurely. I’d recommend alkaline AAA batteries, which are cheaper and are only a small weight penalty (yeah I know that’s blasphemy on BPL, but look at my profile…I’m not an UL’er anyway, so there :-)).

Jonathan Ryan
( Jkrew81 - M )

White Mtns
Best in Show on 04/01/2010 19:31:24 MDT Report Post Print

Rating: 5 / 5

I have been using the EOS-R for alittle under a year now and have been super happy with it. For some odd reason I find night-time winter trail running "fun" and this is the only headlamp I have ever found suitable for the job. On the medium setting the current regulation gives the battery enough juice to last me for several weeks. It is def on the heavy side but that is to be expected with a piece of kit is this bomber!

Edited by Jkrew81 on 04/01/2010 19:34:43 MDT.

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