REVIEWER INFORMATION
Name:  Thomas Lindemuth
Age:  39
Gender:  Male
Height:  5 ft 10 in (178 cm)
Weight:  195 lbs (88 kg)
Hat Size: 7-1/2, or 23.5 in (60 cm) circumference
Email address:  tlindemu(at)ix(dot)netcom(dot)com
Location: Oakland, California  USA

 

Backpacking experience:  I've camped my whole life, and backpacked occasionally starting at age 12.  After a break of several years, I've picked it up again starting about three years ago, and I am currently introducing my sons to the joys of camping.  When not backpacking I greatly enjoy day hikes, and make a regular practice of hiking the trails near my home.  I tend towards heavyweight backpacking (tent rather than tarp, for example), but I am experimenting with ways of lightening my load.  I don't expect to go hardcore ultralight, but I've dropped nearly ten pounds off my base weight so far.  I generally camp in the mountainous regions of California.  I am a destination backpacker, not a through-hiker.  I enjoy hiking in, setting up base camp, and exploring what is nearby.

 

PRODUCT DESCRIPTION
Product Name:  Princeton Tec Corona LED Headlamp
Year of Manufacture:  2004
Manufacturer:  Princeton Tec
Manufacturer's Website:  http://www.princetontec.com

 

 

Light Source (manufacturer's spec):
•  8 Super Bright White L.E.D.'s

 

Weight (manufacturer's spec):
•  8 oz (227 g) with alkaline batteries

 

Weight (as measured):
•  8.2 oz (232 g) with alkaline batteries

 

Size (as measured):
•  Battery pack:  2-3/4 in (7 cm) x 2-3/4 in (7 cm) x 1 in (2.5 cm)
•  Lamp housing:  2 in (5 cm) ovoid x 1-1/4 in (3 cm) thick
•  Straps: 1 in (2.5 cm) wide elastic webbing; approx. 25 in (64 cm) maximum circumference (unstretched)

 

Batteries:
•  3 AA Alkaline or Lithium (3 Duracell alkalines supplied in package)

 

Battery Life (manufacturer's spec):
•  8 LEDs: High 30 hours, Low 36 hours
•  5 LEDs: High 38 hours, Low 45 hours
•  3 LEDs: High 46 hours, Low 55 hours
•  1 LED:  High 55 hours, Low 70 hours

 

Features (from box):
•  Current Regulated For Maximum Brightness and Run Time
•  Designed To Work With Alkaline or Lithium Batteries
•  8 Super Bright White L.E.D.s
•  Select betweeen 4 Brightness Levels (8, 5, 3, or 1 L.E.D.)
•  Lifetime Warranty
•  Water Resistant 1 (whatever that means)

 

MSRP: $49.99 US 

 

Reading the Corona information at the Princeton Tec website got me ready and looking forward to trying out what appeared to be a bright and versatile light.  I was a bit surprised that the Corona page did not have tables of technical specs, such as weight, light output, or battery life (unlike many of the other product pages at their website), but the descriptive material promised a treat.

 

The Corona arrived in the mail nicely packed, shipped, and intact.  The product box is attractively designed, and has all the technical specs that I had been wishing for from their website, including a table of battery run times for the various brightness levels.  Inside the product box, all components are housed in a clamshell pack.  This clamshell is not welded shut, which is nice for easy opening at home, but it means that someone might have, ahem, "inspected" it in the store.  Checking for missing items before purchase would not be a bad idea.  In this case, the items to check for include the light itself, the manual page, a warning sheet regarding radio interference that might affect avalanche beacons, and the three AA Duracell alkaline batteries (providing these is a nice touch, in my opinion).

 

My first action was to examine the light, top to bottom.  I was impressed with the fit and finish.  The plastic components are all well-molded and fit cleanly together, with practically no signs of flashing or other molding artifacts.  The wire between the battery case and the lamp housing appears to be reasonably thick, and it uses strain relief boots at both ends.  The cord is also clipped to the elastic headband, to help prevent it snagging on things and yanking the connections.  The elastic headband is thick and resilient, the stitching appears to be solid, and the ends of the elastic appear to have been heat-sealed to prevent fraying.  There is nothing flimsy that I can find on this light. 

 

On the other hand, all that sturdiness means it weighs a fair amount.  Eight ounces (227 g) is more than twice as much as the other solution I've been experimenting with (a handheld, four-AAA-cell LED light on a homemade headband).  What with working on reducing pack weight wherever feasible, I'm not eager to add another quarter pound back in if I can avoid it.  However, there are some shortcomings to the fit and light output of my experimental model, so I am curious to see if the performance of a true dedicated headlamp is worth the extra weight.

 

DOCUMENTATION
My first thought was to see how idiot-proof it was, that is, to just use it without consulting the documentation.  Caution won out over enthusiasm, however -- I knew that many LED lights will burn out with the batteries in backwards -- so I paused to peruse the manual:  a small, five-panel, two-sided foldout sheet.  The manual contains instructions regarding battery installation, operation, troubleshooting, warranty information, and a couple of warnings that were interesting and also illuminating as to design quality.  In particular, I learned that installing the batteries backwards can indeed cause damage to the circuitry; however, the battery pack is designed to physically prevent that from happening.  (More on that below.)  So it appears that "idiot-proof" describes the Corona pretty well, after all.  Barring malice aforethought, and aside from universal caveats like not mixing new and used batteries and not dropping it in the lake, there is relatively little that the user can do to screw things up.

 

One warning that was mildly alarming is that the heat sink at the rear of the lamp housing can reach temperatures as high as 170 F (77 C).  Of course I had to try that out immediately, envisioning flaming hair, or at least a branded forehead.  After an hour at high power, the lamp housing becomes mildly warm to the touch (the heat sink is protected by a plastic shield with ventilation holes).  I don't expect this will be a problem, but it did raise my eyebrows when I read it.

 

What the documentation tells about battery life is somewhat fragmented, and needs a bit of deciphering to put together the whole story.  The outside of the box gives a battery run time of 30 hours at high output, using alkaline batteries.  (See specifications above for the whole table of run times from the box.)  The manual, however, says "the length of time at constant brightness on the highest power setting will be short (5 to 30 minutes depending on batteries used.)" It then mentions constant output of 12 to 16 hours using dim mode and lithium batteries.  The comparisons are confusing, because they are changing the battery type as well as the power mode, and there are several related bits of information found in separate places.  And that mention of 5 minutes...yikes!

 

Apparently what is going on is this:  on high power, for a given number of LEDs lit, the light will produce steady, bright output for a fairly short amount of time (the 5 to 30 minutes from the manual), before slowly dimming over the remaining life of the batteries (the 30 hours on the box).  Dim mode will produce light that is dimmer to begin with but steady for a longer time, before fading as usual as the battery is used up.  While high power mode drops out of constant brightness sooner, it still takes a number of hours to dim down to the same level where dim mode begins. And, of course, lithium batteries will last much longer than alkalines.  To present the whole picture more clearly, it would be nice to see two separate tables (one for alkaline and one for lithium batteries), that specify both time to first dimming, and total run time, by number of LEDs lit and by power mode.  Maybe it's just me, but I like knowing exactly what is going on, in excruciating detail, and I like it all in one place.

OPERATION
Battery installation: is simple and straightforward.  The battery compartment is opened by first flipping open the latch, then opening the compartment like a clam shell, exposing the battery clips. The latch on the battery compartment is quite stiff.  The manual suggests squeezing the two halves of the battery compartment together to make opening the latch easier, and if necessary, using a coin to pry the latch open. The battery compartment has a rubber gasket to improve water resistance.  The box has a logo with the words "water resistant 1" and an image of raindrops, but nothing more specific than that.  I assume that means safe to use in the rain, but not safe to dunk in the stream.

 

As noted in the manual, the battery compartment is designed so that standard AA batteries only fit one way.  There is a plastic barrier on each positive terminal that allows the button on the top of an AA battery to stick through and contact the terminal; but if the battery is put in upside down, the flat bottom end won't touch the contacts.  Also, the negative terminal has the typical coiled spring contact.  This should make it easy to replace batteries by feel in complete darkness if necessary:  the flat end of each battery goes against the spring terminal.

 

Light operation:  The light is simple to operate.  There are two buttons to control it.  The bigger one, on the right side (as worn on the head) cycles through 5 different combinations of LEDs:  from off, to all 8 LEDs lit, to 5 LEDs, to 3, to 1, to off.  If the switch is pressed within 5 seconds of the last press, it cycles to the next combination.  If the switch is left alone for more than 5 seconds, the next press goes directly to Off.

 

The other switch, on the left (as worn) cycles between three power modes: High Power, Low Power, and Flashing.  These modes can be chosen for any of the selections of LEDs.  It is not clear to me at this point what is the practical difference in light output between, for example, 8 LEDs at low power and 5 LEDs at high.  There is some minor change to the flood pattern of the light, but it is not apparent to me what difference it makes, other than some minor variation on battery life.

 

Both switches require a fair amount of pressure to operate.  They are also slightly recessed below the surface of the lamp head.  Both the pressure and the recessing are probably good because they make it more difficult to accidentally turn the light on in the backpack.

 

The lamp housing is attached to the straps with a hinged plate that allows it to be pivoted to aim the light down for reading or camp chores, or straight ahead for night hiking.

 

Fitting: is accomplished by sliding the straps through the adjusters to set the lengths.  The headband can be adjusted around the circumference as well as over the top of the head.  In addition, the elastic in the headband allows for a wide range of tensions for firmer grip or for comfort.  The adjusters seem to stay put where I set them, not loosening when pulled, only when grabbed and intentionally reset.  Also, the straps are rigged to have no loose ends flapping after adjustment.  I find this to be nice.

 

Light Output:  Initial tests indicate that this is a quite bright light.  One LED is sufficient for reading, while 8 LEDs illuminate an entire wall and allow me to read a clock face clearly at 25 feet (7.6 m).  I notice that the single LED has a slightly different aim than the other modes.  Based on the molding of the LED mounting face, this appears to be deliberate, to help aim downwards for close-range tasks.

 

TEST PLAN
I intend to test a number of things about the Corona:
-- What are the real differences between the various brightness modes?  Is there a practical difference between 8 LEDs at low power and 5 LEDs at high?
-- How well does the Corona light up different situations?  Does it throw light a decent distance as well as create a good flood?
-- How easy is it to adjust the headband to different situations?  Do the straps stay adjusted where I set them?
-- How comfortable is the Corona to wear for extended periods?
-- How well does it work in different weather conditions?  Is it difficult to operate when wet, or with gloves on?  Does it withstand rain or cold?
-- Is the battery life as advertised?

 

I'll be testing in the field in a number of Northern California (USA) locations from late fall through winter (which will involve rain more often than snow), on multi-day backpack trips, local night hikes, car camping, and for general usefulness at home. 

 

Things I like:
1)  Nice brightness.
2)  Fits better than my homemade attempts.
3)  Apparently sturdy; shows good quality of components and manufacture.
4)  Good battery life; even at maximum power, I expect a full 7-10 nights of use on a single set of batteries.

 

Concerns:
1)  Somewhat heavy, compared to some other solutions, though that is a tradeoff for brighter light, better fit, and/or longer battery life.

 

Things I'm not sure about:
1)  The descriptions of battery life are somewhat unclear.  The box seems more optimistic than the manual.
2)  Not sure whether there is a practical difference between lowering the power regulation versus turning on fewer LEDs.