# Princeton Tec Corona Inquiry



## GreySave (May 19, 2008)

Does anyone have any working experience with the current version of this headlamp? I am considering applying for a grant to outfit members of a response team with this, but need to know:

1.) How even and powerful is the flood? Can you safely walk with this in a wooded area with uneven ground for example? Looking for a relatively even flood with perhaps 10 to 15 feet of forward coverage.

2.) How is the tint? Not trying to be picky here, but members of this team will be using it primarily outdoors in possibly in wooded areas with vegetation. Too much blue will likely be a deal killer.

3.) How effective is the regulation on the current version? 

4.) Any other positives or negative about this headlamp?

I am also open to suggestions regarding other headlamps, but they must offer decent flood with enough forward output for walking on uneven ground and must have a minimum two hour runtime on high with four or more hours preferred. Must be weather resistant. AA batteries preferred for runtime and safety (These folks are NOT flashaholics) but will consider 123A powered if the headlamp is truly special. Headlamp must also be capable of being worn on a hard hat or under it.


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## sORe-EyEz (May 19, 2008)

while i do not have the PT Corona, i personally find headlamps with external battery cases less robust. wires could easily end up being cut or twisted. 

personally own the Streamlight Argo HP (early version, not with the C4 LED), its does decent illumination over 15 feet easily. a simple 2 stage output, 5hrs runtime on high. stock beam not the smoothest, a diffuser material would do the trick. 

tech specs on PT brochure for Corona:-
35lumens (brightest setting i suppose?),
37 meters (brightest setting i suppose?), 
30-70 hrs burntime,
8oz with batteries, 
8 brightness levels, 4 flash modes, regulated output, 
water resistant (IPX-4, resistant to splashing & quick dunkings)


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## half-watt (May 19, 2008)

i have three PT Corona's [see EDIT #3 below] and a PT Corona Extreme (both available from BrightGuy.com; both costing the same $47.95).

i find the beam color to be on the cool side, i.e. a slight bluish hue which is somewhat noticeable when "white wall hunting", but NOT objectionable, IMO, even for this use. however, i can't say that i notice any blue tint outside or even in use in a dark basement. of course, YMMV, as LEDs vary in regard to tint from manufacturing batch to batch. on fresh alkaline cells my Corona's all show more blue than the CoronaExtreme which shows almost none.

i can't comment on burntime as i don't really pay att'n nor have i done any burntime tests. 

have seen plots of 8HI beginning at 510 lux [the tester's table shows 510, but his plot show ~560 or 570 lux] (on that particular light meter at 2 feet [don't ask me why that particular tester uses 2' instead of 1' or 1meter as is often used elsewhere]) running off of alkaline cells and a 50% of max value at about 6:00 hours and 100 Lux at about 13:00, the 8HI curve ending at about 18h at about 50lux.

the only other mode tested by that tester was 3LED HI. 3HI started out at ~225lux on the plot (275 lux in his table??? don't ask!) and showed a ~50% value at around 12h and crosses the 8HI curve at around 13h, but then continues to decrease linearly to ~50lux at 27h and his curve goes out to ~25lux at 35h.

both curves on his plot really didn't look to be regulated at all, IMO. these curves came from Backpackinglight.com, but i don't know if non-Premium members are able to view them (some of the website's content is reserved for paying members; i can't recall if the Corona review was among the "premium" content).

the CoronaExtreme version it is noticeably brighter (side-by-side unaided "eyeball" testing, NOT Lux/Light meter readings) on 8LED HI than the regular 3xAA 4.5VDC PT Corona - the diff is really quite noticeable though i would say that it isn't even close to being twice as bright - at least not to my eye.

the CoronaExtreme uses 8xAA cells in a 2x4 cell parallel arrangement. so, very long burntimes, and regulation is maintained far longer. even better, using Li primary AA cells give the best regulated burntimes for all four HI modes (i.e., 8LED HI, 5LED HI, 3LED HI, and 1LED HI) - this is true for both the Corona and the CoronaExtreme.

Mfr. claimed regulated output burntimes on the regular 3xAA 4.5VDC PT Corona is not too good on 8LED Hi as regulated burntime is only 5min to 30min, but it then runs unregulated for quite a while thereafter. other modes of the Corona run in regulation longer or so the mfr. claims.

i don't prefer the Corona for nighttime trail navigation since it generally fails to meet my personal requirement of being able to pick out faded, lo-contrast blazes on rocks and tree trunks from a minimum of 30' away. however, my age degraded (it's downhill to 100 for me), but otherwise normal, low-light vision ought to accept, perhaps, part of the blame for this. 
other than this aspect, either Corona model is otherwise a very fine headlamp for lighting up a large area in front of me. when coupled with a small lightweight Cree/SSC LED flashlight, or an incandescent light that is used intermittently, either of which give much better throw than the Corona/C-Extreme, they form a nice combination.

the CoronaExtreme is sold as a BIKING headlamp. what i did was unscrew the "head" (they're identical on both models of Corona - pics are on BrightGuy.com here==> http://www.brightguy.com/products/Princeton_Tec_Corona_Extreme_BIKE_Light.php) from the bike mount and screw it onto one of my PT Corona headband "head" brackets [after removing the standard Corona "head" of course; and i also remove the battery pack too. this converted it from a bike light to a headlamp - simple enough to do.

please let me know if i can try to answer any more questions for you.

-----
EDIT:
just checked - that Corona Review appears that it will be accessible to non-Premium members. here's a link: http://www.backpackinglight.com/cgi...princeton_tec_corona_led_headlamp_review.html

EDIT:
re-read your Post. IMO, you ought to have no trouble walking on uneven terrain and be able to see 10' to 15' in front of you (i have used the Corona in precisely this manner).

the CoronaExtreme comes with a bracket+velcro bike helment mount. if permitted by your safety regulations, it would NOT be difficult to cut two very small slots in each helmet and pass the velcro straps through the slots, thus mounted the bike-helmet bracket included with the PT CoronaExtreme on a hard hat. also, the top/bucket strap of the regular Corona is removable if(???) that will help wearing the Corona under a helmet.

EDIT #3:
why three Coronas? one is kept "stock", so to speak. my second was purchased to make a very simple mod to, i.e. i cut the cable going from the battery box to the head and added connectors (phono plug on the box and phono jack on the cable going to the head). this allows me to use some home-made +4.5VDC remote battery boxes (with a similar phono plug) holding 2x3xAA (parallel-series arrangment), 3xC, or 3xD cells in my pre-CoronaExtreme attempt to increase burntime while still being able to re-connect the rear mounted battery box holding 3xAA cells as a b/u power supply if and when the home-made extended capacity remote power source runs down during a very long outing. the only area that i didn't often don't do UL backpacking in was in the lighting area.

note, i do this for many headlamps with rear headband mounted battery boxes. i use 1/8" aka 3.5mm aka 'mini' "phone" plugs and jacks on +6VDC systems and "phono" plugs and jacks on +4.5VDC systems. if using NiMH cells on a headlamp that can handle some overvoltage, then i can use (though i haven't yet) the four cell boxes (normally +6VDC with alkalines) and a phone-2-phono adapter.

the third Corona was initially purchased as a back-up (so, it's really the second Corona - chronologically speaking) b/c i really like this headlamp, and then it was disassembled to allow the CoronaExtreme to be mounted to the headlamp bracket/headband assembly.


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## Burgess (May 19, 2008)

Edited to add:

Hello *half-watt*, and others --

Just wanna' explain my "eating popcorn" animated image (above).

That simply means that *i find this thread interesting*,
and i want to continue to follow its progress.

It permits me to "mark" a thread, and also be informed
of any additional posts and comments.


It was *not* a response to your posting.
Just the entire thread in general.


Hope that this clears things up. :wave:


EndEdit
_

_


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## GreySave (May 19, 2008)

Thanx Half-Watt & Sore:

That's useful material. I am still on the fence about this one. I think it will do the trick, but.....I think I'll check out that review and go from there,


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## sORe-EyEz (May 20, 2008)

i got a feeling that in the end your respond team may do with a 2 seperate light for illumination

headlamp for safety hardhat for did distance & close-up and a handheld for throw. for throw, Streamlight 4AA Luxeon comes to mind. throw lights 1 light for every 2 person? 

is battery configuration a major consideration? AA batteries are more economical but lithium CR123s economises in size & weight if going for a stretch...

would any venders loan you a sample set for comparison purposes?  just let them know specs on paper vary widely among manufacturers...


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## GreySave (May 20, 2008)

<< i got a feeling that in the end your respond team may do with a 2 seperate light for illumination

headlamp for safety hardhat for did distance & close-up and a handheld for throw. 

is battery configuration a major consideration? AA batteries are more economical but lithium CR123s economises in size & weight if going for a stretch... >>



Using two lights was always the plan. The headlamps are for when they are carrying an animal or supplies or doing short range work where the hands need to be free or they need flood lighting. We have some Lowes Task Force incans for general lighting and I am looking to acquire LED flashlights to supplement those.

I'd love to use 123A batteries, but these folks are not in any way knowledgeable about their use, and that concerns me. Even with "education" I still would not trust everyone to understand and follow the safety rules for 123A. Plus I am trying to consolidate down to a couple of battery types if possible. Thus I am looking at AA for the most part. Also considering the Apex. I just need to find the time to sit down and go through the lights one by one and choose.


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## sORe-EyEz (May 20, 2008)

GreySave said:


> Using two lights was always the plan. The headlamps are for when they are carrying an animal or supplies or doing short range work where the hands need to be free or they need flood lighting. We have some Lowes Task Force incans for general lighting and I am looking to acquire LED flashlights to supplement those.
> 
> I'd love to use 123A batteries, but these folks are not in any way knowledgeable about their use, and that concerns me. Even with "education" I still would not trust everyone to understand and follow the safety rules for 123A. Plus I am trying to consolidate down to a couple of battery types if possible. Thus I am looking at AA for the most part. Also considering the Apex. I just need to find the time to sit down and go through the lights one by one and choose.


 
oh i see, still i am not that in favor of corded lights though. 

Black Diamond Zenix IQ and PT Matrix II both LED headlamp also uses AAs. well, hope you find the light that works best for outfit.


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## hopkins (May 22, 2008)

This maybe helpful Greysave. -*I googled PT corona , field tests* and 
found this conclusion:

The Corona's design concept has been trumped by newer 1-watt headlamps for non-technical use, especially those that either combine the main LED with one or more 5 millimeter LEDs or provide a flip-down diffuser lens-. As our tests demonstrate, even eight 5 millimeter LEDs can't begin to match the output of a single 1-watt Luxeon. The Corona is both versatile and frugal, provided the many modes are used judiciously, and the light from its massively parallel LED array is good enough to support general backcountry activities and is especially nice for in-camp chores, where a flood-style beam is appreciated. But at eight ounces, the Corona is very heavy for a headlamp that doesn't offer a long-throw pencil-style high beam suitable for technical nighttime activities, such as climbing and off-trail travel. For these pursuits there are better lights, including other offerings from Princeton Tec.

Was the bright yellow plastic color a requirement for your equipment setup?
It looks like something a professional SAR would have.


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## GreySave (May 22, 2008)

Negative on the bright yellow color. I am looking for floody performance and run time. The best flood in the world is useless if they need to stop and change batteries in 30-60 minutes. I recognize that there has to be a compromise between output and runtime, and I have actually been looking at some higher powered single LEDs headlamps with built in diffusers. Hard hat compatability is also a concern, and several of the Streamlight headlamps come with both head and hard hat head bands, so I am leaning that way.

The grant request must go to the EMA office next week, so I will be forced to make a decision soon.


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## sORe-EyEz (May 22, 2008)

i was able to get at least 4.5hrs of almost constant (naked eye test) light from Argo HP (pre C4 version) on high mode. 

as this model goes,

Pros:-
- compact & light weight unit
- cloth & hardhat straps included
- no cords (means more robust unit)

Cons:-
- uses CR123 lithium
- doesn''t flood as well compared to multi-(5mm)LEDs

as light output would be quite subjective i'll leave that out. it would be ideal if the vender has the newer version in stock, assuming an improvement in brightness while maintaining at least similiar runtime. 

that said there is a Haz-Lo (hazardous location) model with a single brightness level...


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## beautifully-stupid (May 22, 2008)

I'm recently a fan of the Myo XP with Seoul p4 LED. 

It gets outstanding run time, and has a slightly yellow/white tint which renders greens and outdoor colors really well.

I'll try the lamp on my hard hat later tonight and repost tomorrow. 

I'd say yes to the 10-15 feet of flood. I've also left the light on high over a 7 hour period with no ill effects. Runs on 3 AA... and works on rechargeable with a hardly noticeable drop in output. lithiums are not suggested however, per mfg. specs. 

good luck with your search.


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## GreySave (May 22, 2008)

Hey BS:

Sorry, could not resist  Is that the new version I have seen? That had caught my eye. How was the output after 7 hours of run time as opposed to fresh batteries? A rought estimate is fine. Your commetns about color rendition have gained my attention as that is also a decision making factor.


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## beautifully-stupid (May 22, 2008)

No prob, my EDCF username is B.S., 

It is the new version. 

Can't remember how the output was, but definitely still good for navigation and hands free use.

If I remember I'll take some pics tonight with some fresh NIMH and run the same test.


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## Hooked on Fenix (May 23, 2008)

I think the closest light to the Corona is the PT Quad headlight. It's bright enough. Overall brightness seems equal to or greater than the PT EOS headlight. It is one of the only headlights made with two low battery warnings (let alone one). The Quad is only $30. It is regulated unlike the Petzl Myo XP. I like that the new Myo XP has an updated emmiter, but for $80, I expect some regulation, and no p.w.m.. If Princeton Tec would update their Quad to Nichia GS l.e.d.s and the EOS to a Seuol P4, Cree XR-E, or TFFC K2 l.e.d., they'd blow away the competition. They are due for an update. Take your pick if you can't wait for more good companies to update their products (They'll have to update if they want to keep their customers. Someone will meet that niche in the market if they don't).


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## beautifully-stupid (May 23, 2008)

after about 8 hours constant high last night, the overall light output dropped somewhere between the medium and low setting with fresh batteries.

for my dark adjusted eyes, Low is plenty of light for walking-speed navigation. 

As far as I know there is no PWM on the new MYO XP, and I'm typically sensitive to it, so I'm not sure about the above comment. 

I do think the Quad is a nice light.

I would also recommend Fox Fury


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## hopkins (May 24, 2008)

Back in 2006 June my partner and I climbed Mt Whitney via the Mountaineers
Route at night.
We both used Myo Xp's. We left the car at sunset and mostly used
lowest setting on the headlamps, as we thrashed up thru the bushes, and stream crossings, then the rock slides and snowfields. 
We would flip the diffusors up and down whenever the situation warranted which seemed such a fantastic feature for route finding

My point is having both spot beam and flood beam available at the swipe
of a gloved hand is a simple -unthinking- to use feature when you have other things on your mind.


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## GreySave (May 25, 2008)

Thanx for your help everyone. I ended up applying for four Princeton Tec Apex headlamps with four sets of the hard hat retaining clips. I really liked the look of the Myo XP, but the user interface was less clean for those who would be newbies, and I also had to be somewhat price conscious. 

I actually need more than four, but the number requested was also due to the need to meet a capped dollar amount. Additional headlamps will be requested in 6-12 months. At that time I will see if anything new has been released and go from there.

Thank you again for your help!


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## sORe-EyEz (May 25, 2008)

good to know you have found your light.  

pity the budget constraints...


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## hopkins (May 27, 2008)

Hi Graysave - Just a thought about your 4 new Apex's .
Seems another owner has just reported cracked plastic around the scews on
the bezel. We suspect the screws are a bit too wide or the holes are too narrow.
Thus the plastic finally yeilds to the pressure and cracks.
I can think reeming the holes out a little so the surrounding plastic is not as stressed would make your Apex's reliable lifetime photonic servants.
A pretest would be if the screws are real tight as you unscrew them. 

btw you and your crew will probably make the cover of some SAR publication
looking so good with those Apex's attached to helmets.

-hopkins


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## GreySave (May 27, 2008)

I saw that thread. Too bad it started AFTER we submitted the grant information.....



Durability is a concern and those comments probably would have ruled the Apex out. Then again, our lights will not see any use during training as night training is a rarity due to the number of safety personnel that would are required. Thus these lights will most likely only be used on actual night activations. Since we are 95% preparation and 5% activation type of organization with only 1-3 activations anticipated per year, the lights should last some time and they are of course warranted by the manufacturer. 

On the budget question that Sore Eyez commented on.....We really are quite fortunate. Thus far the powers that control the grants have been very good to us, so we have been able to almost completely equip (assuming this grant is fully approved) and train a response team in less than a year. That's darn good considering how slowly government agencies can work. When we request equipment we try to select equipment that will allow us to get the job done safely and be reasonably durable without wasting taxpayer dollars. Hence the use of Streamlight flashlights instead of something like SureFires. So I really do not mind compromising on the number ordered or the type of light ordered at this time. It is simply a part of the game.


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## sORe-EyEz (May 27, 2008)

its a case of bad timing i guess. warranty issues aside, i would be really disappointed if my lights fail me when its needed. 

would the relevant government agencies have a database of past purchases? a call to long running SAR teams could prove useful for next/future recommendations for any equipment. :thumbsup: this could save money too. 

as for current lights i wonder if there is any heat resistant silicone applied anywhere to reduce impacts that could be added to minimise its weakness (the hinges)? :shrug:


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## hopkins (May 27, 2008)

sort of like the cover for the Wii remote...


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## GreySave (May 27, 2008)

<< its a case of bad timing i guess. warranty issues aside, i would be really disappointed if my lights fail me when its needed. >>

We will always work as pairs, so even if gear that one of us is carrying should fail no one would ever be alone. 



<< would the relevant government agencies have a database of past purchases? a call to long running SAR teams could prove useful for next/future recommendations for any equipment.Woulnt agencies have a database of past purchases? a call to long running SAR teams could prove useful for next/future recommendations for any equipment. >>

I suspect that they would have a database for the purchases that other Teams working for the same controlling parent organization have made. Trying to access that information would likely be a challenge given the way that our government functions. Plus, since these teams are all volunteer based, the selections that they made may or may not have been based upon any real selection process. There are no official standards for most of our equipment. There may be in time, but right now the concept is very new since it wsas established by law in the Pet Act of 2006 following Hurricane Katrina. I'd like to think that with all of your help we are setting the standards. 

While we may perform SAR as it applies to animals, that would not be our primary function. Our primary function is sheltering. When I started looking at our personal lighting requirements I had very specific needs in mind. This included total light output, beam style, redundancy, decent battery life, durability, and a decent warranty so that we did not have to replace gear that fails under normal use. 

Redundancy means that the Team member should always have light as the flashlights are hybrids and the headlamps have multiple light sources that are even on their own switches if I read correctly. Plus, anyone with a headlamp will also always have a flashlight as well. The primary beam style I wanted was decent flood. Both the headlamps and Twin Tasks should deliver that with throw from the second light source as a bonus. Battery life on both is decent provided the operator uses the correct light source and power level. They will be trained on that. Less is more unless you NEED full output. 

I guess what I am trying to say in my own rambling way is that I saw specific needs that I wanted to fill for our Team to work safely and effectively. While obtaining information from other human SAR teams would be great, I think we were able to obtain everything except "real world experience" from those at CPF. And in fact we did receive some real world experience from CPF as well. I am quite comfortable with the items we selected.


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## Mark620 (May 27, 2008)

In true darkness the apex (outside NO light pollution) only star light through the canopy, the 4 LEDs on low is very bright to night adjusted eyes.


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