Princeton Tec Corona Headlamp

4½ Stars
Very Good/Excellent

Light Type: 5mm LED
Light Class: Outdoor / Rough Use Headlamp

Short Description:

The Princeton Tec Corona is a 5mm LED headlamp with 8 brightness levels and 4 emergency flash modes. It runs on 3 AA batteries and utilizes a current regulator circuit for all modes of operation. It is water resistant to 1 meter and uses a 3 point adjustable elastic strap and pivoting headplate for ease of use and comfort.

Bezel picture
Beam Profile

Detailed Information:

"5mm LEDs? With Luxeons dominating the market for bright LED lights? How old fashioned!"

Funny how bright white 5mm LEDs just came out a few years ago, and yet those of us who keep up with the industry tend to view them as almost "out of date" with the Luxeon high-flux LEDs gaining ground. Well, the Corona is a reminder that white 5mm LEDs are here and they are here to stay.

The "body" of the Corona consists of 3 parts: the bezel, the battery box, and the straps.

Starting at the front, you will find an odd shaped polymer bezel which contains several important features. First, it is sealed for water entry to 1 meter depth. Essentially, it is rainproof and a dunk in the pond won't bother it either. The very front of the unit sports 8 white 5mm LEDs in a dull gray reflector. LED are by nature very impact resistant, so no blown bulbs to worry about with the Corona. The reflector has been shaped around the various LED "banks" to enhance the beam pattern depending upon which output level you select. All of this is protected behind a polycarbonate lens. The bezel is attached to the forehead plate via a hinge which allows the bezel to be smoothly tilted more than 90 deg. for vertical adjustment of the light beam.

On top are the two switches which control your output modes. The larger, flat switch controls the number of LEDs you will be working with. The first click gets you all 8 LEDs. Second click shuts off the top bank of 3 LEDs, giving you 5 on. Third click turns off the 5 bottom LEDs and turns on the top 3 again. Finally, the last click turns off all but the bottom one. Another click starts the cycle again. Pausing during any part of the cycle for more than 5 seconds causes the headlamp to turn off with the next click.

So what is that smaller, wart inflicted button for? That allows you to select high, low or blink mode for each of the LED modes mentioned. Want lots of light, but don't want to kill your batteries? Pick a bright mode and kick in the power savings option! The low mode provides 40%-50% of the light of the high mode, but uses only 25%-30% of the power of high mode. Less light, but a significant increase in runtimes.

How is all this possible? Through the use of a current regulated power supply inside the head of the light which provides non-flickering dimming of the LEDs as well as constant output from the LEDs over the life of the batteries. Up until now, dimming modes usually were achieved in better headlamps with PWM regulators. These regulators flicker the LEDs very rapidly to create the illusion of dim light. A much better solution than using resistors, the PWM dimming made it look like you were in a disco full of strobe lights if you moved quickly or were trying to read a book. Current regulated dimming results in no flicker; just a smooth flow of dimmer light.

Now one of the big issues with LEDs of any sort is that they produce heat when you push them pretty hard. This heat isn't felt at the front of the light like with incandescent lights, but it builds up inside the LEDs. If you don't get rid of the heat, damage can result. To solve this problem, Princeton Tec has added an aluminum heatsink to the back of the bezel, yet maintained the watertight integrity of the casing! It's about time someone figured out how to do this! The excess heat created by running the LEDs on their bright modes is dumped to the heatsink and safely removed to the environment. There is a plastic guard behind the heatsink and it would be smart to leave it in place. On "high" mode the heatsink can reach 170 deg F. which is hot enough to burn skin.

Output is in the form of a wide flood of bluish tinted light. Pretty typical of 5mm white LEDs. Great for close to medium range work.

# of LEDs
200 (14.14)
2310 (23.10)
94 (9.70)
1050 (10.50)
122 (11.05)
1319 (13.19)
58 (7.62)
629 (6.29)
77 (8.78)
823 (8.23)
38 (6.16)
408 (4.08)
26 (5.10)
238 (2.38)
13 (3.60)
119 (1.19)

All throw readings are in Lux at one meter. The numbers in parenthesis are for comparison in the Comparison Charts.

I'm not even going to bother with the advertised runtimes, since Princeton Tec considers the end of the runtime when you can no longer read fine print on a newspaper at 6 inches. I really wish they would have stated the runtimes to the point where the LEDs drop out of regulation like they did with the EOS headlamp. I will mention that in the documentation it states that regulated runtime on high will be relatively short - 5 to 30 minutes - diminishing thereafter. Dim mode greatly extends the constant output runtimes. It also states that using lithium AA batteries will allow the dim-8 LED mode to last about 12-16 hours!

Lithium AA? You bet! The Corona can run on AA alkaline, L91 lithium AA, or rechargables. Using lithium will extend runtimes relative to alkalines, while rechargables will result in shorter runtimes. The battery box is closed with an easy to use flip-clip. No tools needed here, and no fumbling. Reverse polarity protection is built in, so no worries about putting the batteries in the wrong way. The box is sealed for water resistance.

The battery box is connected to the bezel via a cable with 2 clips on the headband and stress grommets on each end. Positioned in the back, the batteries help balance the headlamp for comfort.

I don't want to forget to mention a couple of other little features. The straps are all attached to the headlamp via slotted loops which allow the bands to be easily removed for cleaning or replacement. The clips on the side are made the same way. The elastic bands are fully adjustable for size. .

What I Liked: Waterproof to 1 meter, Tough/impact resistant, Current based regulation, Good battery life, Bright, Easy battery change, Lightweight, Accepts alkaline, lithium and rechargeable batteries, Easy to use.

What I Didn't Like: Nothing.

Other Things I Noticed: There is a warning in the box regarding Avalanche Beacons. It states that the electronic controls in the light may interfere with an avalanche beacon reciever set on or near its maximum. It will not affect avalanche beacons in transmit mode.

Conclusions: Fantastic close/medium range headlamp. The only plastic headlamp out there with a metal external heatsink to protect the LEDs from damaging heat buildup and a current regulator circuit. Bright modes allow for ample light, while dimmer modes provide for very long runtimes. Load it up with lithium batteries for even longer use and for good cold-weather performance.

Quick Facts Table:

Review Date ............................. December 2004
Case Material ........................... Polymer
Case Features .......................... Tilt adjustable to 90 deg.
Case Access Type .................... Flip clip fastened clamshell design
Switch Type ............................. 4 mode clickie and 3 mode secondary clickie
Reflector Type ......................... Dull silver
Lens Type ................................


Bulb Type ................................. 8 x 5mm white LEDs
Beam Type ............................... Flood
Beam Characteristics ............... Bluish tint, more evident toward center
Throw (Lux) at 1m (click for description) See table, above
Overall Output (click for description) See table, above
Battery / Power Type................ AA alkaline, lithium, or rechargeable
Battery Life (advertised) ........... See table, above
Environmental Protection ......... O-ring seals
Weight (oz.) with batteries ....... 8.0 oz.
Special Items of Note ............... Alkaline batteries included
Warranty .................................. Lifetime
Retail Cost ................................ ~ 49.00 US$ at time of review


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