Photon 3 (White), retail $17.95 (
Buy them here or here.
Last update: 04-27-04

Photon 3

The Photon 3 is the latest successor to the very popular Photon Micro Light product. Housed in a virtually indestructible glass-reinforced resin casing, the Photon 3 is a bright, single-LED lithium battery light that uses a microcontroller & two hidden dome switches on a circuit board instead of the traditional mechanical switch with parts that stick out everywhere.
This enables the light to do some tricks that simply cannot be done by LED & battery alone. This also eliminates an external switch that can leak or break off.


The Photon 3 comes with batteries already installed, leaving you only to pop off the back and remove the insulator from inside the battery compartment. This clear plastic tab type insulator is there to ensure the light arrives on your doorstep with the freshest batteries possible.
Apparently, some people have been missing this, as there is now a new vendor advisory sheet describing this procedure and asking that Photon 3 buyers be told of this insulating tab when they purchase.

To get a quick shot of light anytime, just squeeze the button towards the front of the light's casing. The real magic is in the rear button. When you press and hold down the rear button, the Photon 3 cycles through all of its modes: Auto Off, High Brightness, Medium Brightness, Low Brightness, Fast Strobe, Medium Strobe, and Low Strobe.
The strobe modes aren't true strobes because the "on" time is relatively long, so you can probably forget about trying to do true stop-action effects - however you can stop or reverse an electric fan or other fast-moving object with the light's Low mode.

While the rear button is being held, the light will keep each mode on for just under 4 seconds, then move on to the next. To stop at a mode you want, just release the button. The next time you press it, the light turns off, but it "remembers" the last mode that was on, and activates it the next time you use the light by pressing the rear button.

To get the maximum brightness on demand, just press the top button anytime; it immediately overrides the microcontroller and gives full power regardless of the light's previous setting. This button is momentary only, so you have to hold it down for as long as you need the full brightness; once you release it the light returns to the mode you used last, or turns off if it was already off to begin with.

The light comes equipped with a small tail ring & large sturdy chrome keyring for quick & easy attachment to your keys; you may also remove the keyring and affix the Photon 3 to to lanyards, clips, or other attachment accessories of your choice.

Unlike the Photon 2, changing the batteries in the Photon 3 is a tool-free and screw-free process. Just turn the light upside down, and carefully pry the battery cap off by inserting a ballpoint pen or the tip of a nail file under the tab; then pulling the cap off once the tab is lifted far enough for you to grasp.

Remove the two dead batteries and toss in the nearest bidet... no wait, better make that the nearest garbage can instead. :) Lay in two new ones, flat side (+) facing you; being sure the edge of the top battery fits under the small metal tab on the inside edge of the case.
(Newer models: slide the batteries into the case so that they go under the large metal retaining strap - this strap or bridge replaces the much smaller and more easily damaged tab found in earlier models).
Now, lay the battery cap over the opening, being sure to align the little tab with the slot it fits into at the tail end of the light, and simply press the cap into place like you would the lid from a Tupperware bowl. You'll feel that satisfying "Tupperware snap" as the cap is fitted in place. :)

More than ever, it is important that you get the batteries in correctly. With just an LED, you can sometimes get away with it, but with the new microcontroller something nasty might happen if you put the batteries in backwards.

Current usage at standby (light "off") was measured at just a couple of microamps - this will not affect battery life, yet is enough to maintain the light's internal memory. Nice circuit. :)

Live Battery Porn - Watch 'Em Go!!

Like its predecessors, the Photon 3 is one tough cookie. The housing is made of a glass reinforced polyurethane compound, and is, for all intents and purposes, indestructible. The LED is surrounded on its sides by a transluscent plastic grommet, and the light is supposed to be submergible to at least several feet. The instruction card doesn't specify the degree of water resistance, but does provide instructions for resurrecting a flooded light. The only real construction fault I can find is lack of protection for the LED; after being dropped a lot or spending a lot of time in a pants pocket with change & keys, the LED's finish will become marred. The LED has been known to break in a head-first fall, but this probably doesn't happen very often and I honestly wouldn't worry about it.

The Photon 3 has a number of different modes programmed into it.
Auto Off is just that. When the light is left on in this mode, it shuts itself off after approximately one minute; signalling both activation and deactivation with several seconds of fast blinking.
High mode is the light's high brightness setting. Medium mode dims the LED considerably, and Low mode dims it way down; this is useful for situations where absolute maximum battery life is a necessity.
Fast strobe causes the light to blink around 8 times a second; this might be useful in party or rave situations or for signalling. Medium strobe blinks around 3 times a second, and slow strobe is a mode where the LED is on for 1/2 second, and off for another 1/2 second; repeating infinitely.

Although the Photon 3 is undoubtedly a nice light with nifty features that a lot of you would use, some people *may* find that mode cycle time seems a bit too long. In order to cycle through all of its modes, constant, uninterrupted pressure must be maintained on the rear button for 22 to 24 full seconds; after several such cycles, my fingers were no longer strong enough to do this without interrupting the cycle and causing me to do a little dance number, say something with a lot of four-letter words in it, and start over. Actually, it's not so much as starting over, but resuming the cycle with some extra seconds tacked on for punishment. For testing purposes, I've simply strapped it to a table and used the butt of a soldering aid (a pair of heatsink forceps) to hold the button down & run the light through multiple cycles.
(The NEWER MODELS have addressed this problem somewhat with a much easier to squeeze microswitch control that is less tiring to maintain pressure upon)

The one-button override to get the highest possible brightness in an instant does help, but this button must also be held in for as long as you need the light.

An issue that is probably just nitpicking is that the light strobes rapidly for 3 seconds when you activate it in "Auto Off" mode. A few quick blinks would have been enough, but to have to wait 3 full seconds before you can get usable light could become a bit annoying after awhile.
This leads to a possible source of confusion while changing modes - for this mode starts out a lot like the Fast Strobe mode; which may fool you into needlessly holding the button down, missing Auto Off (thinking it was Fast Strobe), and having to cycle through the whole set all over again. So you should PAY ATTENTION when you do a mode change. Auto Off is right after Slow Strobe, remember that. :)

beams from Photon Micro Lights
Photon 3 doing a number on the test target.
Brighness levels:
OVERRIDE: 20,600mcd
HIGH: 19,100mcd
MEDIUM: 5,800mcd
LOW: 1,800mcd

The Photon 3 is just as bright as its predecessor. Please note though, the high reading of 20,600mcd is an "instantaneous" reading, and will drop to around 15,000mcd (15 foot-candles) after the light has been in use for 1-2 minutes, upon which it will then fall much more slowly to around 13,000mcd after 5 minutes and pretty much stay in that range. For those who just use the light in brief spurts, the 20,600mcd figure isn't too unrealistic.

Auto Off and High modes are *almost* as bright as Override mode; you actually have to activate Auto Off or High, then repeatedly press & release the override button in order to notice the difference. In my estimation, the difference is approximately 5%. The natural fall-off in brightness due to the batteries occurs too quickly to get a stable meter reading; so I had to guess this figure.
(Note: I have since metered it successfully; note the figures above).

The dish on Photon 3
The Photon 3 is the next logical step in LED flashlight evolution, but it has some issues. The concept of a microcontroller chip in a micro flashlight is great, but the time it takes to cycle through its seven modes is way too long, especially when your hands are cold or arthritic. Squeezing the light without interruption for nearly half a minute may not be very convenient for some users, such as if you need to change modes in an emergency situation. My advice is to keep it in your favorite mode all the time, so it's always ready when you are.

The idea of auto-shutoff is also wonderful, but they should shorten the "blink" period to maybe 1 second at turn-on (leave the turn-off sequence alone) and have the light stay on for 2-3 minutes before it goes out, instead of 1 minute. This is my OPINION ONLY, and should be taken as such!

Now, the question has been asked: "What do you do with all the different modes?"
Let's see if I can help answer that. I've already heard a few ideas from the inventor and also have some of my own thoughts on this. Let me share both with you:

BRIGHT: When you need the brightest possible light you can get out of a single LED, choose this mode. You can shine it 20 or more feet away in dark woods, sheds, garages, and homes. This mode is also useful when you work on electronic equipment or DJ gear and need to distinguish differently colored cables & wires.

MEDIUM: This mode is useful when high brightness is just a bit of overkill. Most night foraging missions will succeed on Medium, and your batteries will last around 10 times longer.

LOW: This is the perfect mode to use after your eyes have become accustomed to darkness. It is bright enough to use for navigating dark rooms, finding & hitting the toilet, or reading inside the tent. Expected battery life is somewhere between 50 and 100 times that of Bright mode. Because of this, Low mode can also be useful in emergency situations where batteries might be hard to come by for awhile.

FAST BLINK: Use this mode for signalling & locating. Put this on the top of your tent door and you'll never stumble into the wrong tent ever again. Kite flyers also want something eye-catching to attach to their kite, and something like this *would* catch the eye. Having several Photon III's in different colors, all set to fast blink and attached to a kite might end up garnering a few extra calls to the UFO reporting center.

MEDIUM BLINK: This mode can be used much like Fast Blink, but the blink rate is substantially slower. Another option for signalling & hobbies; this one is also useful for bicyclers & scooter riders who want to be seen but don't want to give someone a seizure. A bit of Velcro brand fastener to the handlebars and to the back of the light will affix it to your vehicle, yet leave it easy to remove & take with you to help prevent theft when your bike or scooter is left unattended.

SLOW BLINK Put a couple of these on the wingips of a RC model airplane and you might get a call from the FAA. :)
This is another option for signalling & location. A Photon III set like this and hung from the dog's collar might help you keep track of the pet during those nighttime walks or off-leash pee-pee trips.

The military already uses a lot of Photon II's; the uses for the Photon III will make them even better for this. Troop leaders can identify their troops in training missions if each one uses a different blink rate; they can also be used for search and rescue training missions to identify "victims".

AUTO OFF: Do you always forget to turn flashlights off, only to come back later and find they're full of dead batteries? Then this mode is for you. Another idea the inventor suggested is to stick a Photon III on the wall in a hallway or small room you often pass through after dark; just give it a little press and the hall is lit up for you without having to fumble with the lightswitch or get blinded by rows of 100W bulbs in the ceiling; and you never have to remember to turn it off.
Vacationers can stick one of these on the hotel nightstand or bathroom basin and use it the same way - give it a little press, have light long enough to pass through the darkened area(s) and never worry about shutting it off.

UPDATE 06-07-01:
The Photon 3 is now available in a version with a transluscent plastic hosel over the LED; this is to allow one to affix the same "Crystals" as the RAV'N uses, thus extending the P3's versatility to the party & dance environment.

UPDATE 06-22-01:
I'm still intent on doing a run-time test with all modes, but right now I don't have the money for batteries, nor do I have any extra sets available. Sorry guys... maybe someone with deeper pockets can beat me on this one.

UPDATE 07-14-01:
Crude testing has determined the pulse rep rate of "medium" and "low" settings are identical - approximately 255Hz (square wave) - only the pulse width is modified to obtain the two distinct settings.

UPDATE 09-05-01:
Thanks to LRI, I have been supplied with all the batteries necessary to do run-time tests on the Photon 3.
These tests will be conducted as time permits - I have several lights currently in-testing, but may have some time towards mid-month to run the Photon 3 tests.

I have also learned that the newer generation P3 has replaced the gold plated bridge contacts with dedicated microswitches, which should eliminate all complaints about finger strain while holding down the Mode Change button.

UPDATE 10-23-01:
I now have a new generation model that not only has the microswitches, but a new battery retainer that is harder to deform or destroy. The new strap actually goes all the way across the board and holds the batteries in place, so even if the battery door becomes lost, the Photon 3 will still work and you can then use it to find its own door.
Now where did I put those pictures...

Battery life testing in all modes is still scheduled, but there are a couple of other lights ahead of the P3, plus I have an audit in progress (thanks, FEMA!) so please be patient.

UPDATE 01-22-02:
I have intentionally left a new version Photon 3 with new batteries sit unused for several months to determine any untoward effect on the battery, and there was none. When I reached for the sample for a comparison test earlier this evening, it was as bright as if it had just come out of the package. Earlier versions of the P3 would occasionally drain the batteries when left idle, but this problem has apparently been fixed, and has been fixed for months. If you have the new version with the battery tie-down strap, you shouldn't have to worry about the batteries dying while the unit is idle.

UPDATE 04-17-02:
New logic is being introduced to make the Photon 3 easier to use, addressing virtually all concerns I had with the functionality. Expect these new units to start showing up later this year.

UPDATE 09-01-02:
The "New Logic" Photon 3s in non-violet colors are just now beginning to come out of the woodwork. The logic is identical to the Purple P3 that I review HERE. To put it simply, the new units have improved the chip (actually, they replaced it with an entirely new chip) to eliminate the metastability problem that made it eat batteries, and they have shortened the dwell time in mode change from 4 seconds to well under 2. One of the flashing modes was also replaced with an automated distress signal. Physically, the "new logic" P3 looks just like any other P3.

NOTE: To identify a "new chip" model, take the batteries out and look for "2002" right below where it reads L.R.I. If the new logic proves to be stable over the long term, I may slightly modify this product's rating. Not that it's bad now - the current rating is actually quite good, and isn't something to hang you head in shame over.

UPDATE 02-27-04:
Today, I received the new "Hands Free Photon Clip" directly from LRI. This simple device allows you to use your Photon light hands-free; clipping to the brim of a hat or to a shirt pocket or even to your collar if your shirt does not have a pocket. You can also clip it to the bridge or lens of your eyeglasses if you wish. The fairly stiff spring-loaded clip has serrated "teeth" on the inner faces of the clip, so it ought to stay put where you clip it on. A ball & socket joint on a pedestal allows the flashlight to be pointed just about anywhere when it's affixed to the clip. There were no instructions provided with my evaluation sample, but I think it's intuitive enough that you probably won't need them.

In case you can't figure it out though, it kinda goes like this:

Insert the front (LED-end) of your Photon Micro Light into the front of the clip where the two larger and more widely-spaced plastic tits are. After the front of your flashlight is in there, lower the rear side of the flashlight (where the keychain hole is) into the two narrowly-spaced plastic tits on the Hands Free clip. Be sure it's on there all the way so you don't lose your Photon light. Clip it to whatever you want to clip it to. Turn your Photon on, and aim it wherever you need the light. Finally, turn your Photon off, at least until you're ready to use it.
There, that was easy, wasn't it?

Here's the device itself, compared in size to a Photon 3.

And here it is, clipped to the brim of a baseball hat.

And, finally, here it is clipped to a pair of eyeglasses, while I'm using them.
My eyes are closed in this photograph because one of them is still {vulgar term for having had intercourse} up from (crash course in) brain surgery I had in late 2002.

The Hands Free Photon Clip costs $4.95, but is included free of charge if you buy a Photon II or Photon 3 from LRI's website by 03-15-04.

Updates to this page will occur as needed.

Super bright in HIGH mode
Durable construction
Good color rendition
Useably wide beam
Doesn't discolor when dimmed
Tiny in size
Easy to carry & store
Better water resistance than the original
Screw-free battery changing
No plastic switch to fumble with, leak, or break off.

Cycle time for mode change is too long
Batteries can be expensive & hard to find in an emergency.

    PRODUCT TYPE: Mini keychain flashlight
    LAMP TYPE: LED, 5mm, all colors + IR + UV
    No. OF LAMPS: 1
    BEAM TYPE: Circular, quality varies with LED type
    SWITCH TYPE: Snap-action microswitches with digital signal processing.
    BEZEL: None
    BATTERY: 1 CR2032 or 2 CR2016 lithium coin cells
    CURRENT CONSUMPTION: Varies, 2 uA to ~60 mA (req. re-measure)
    SUBMERSIBLE: No, but should be OK after accidental dunking
    ACCESSORIES: Battery(ies), split ring
    WARRANTY: Full lifetime


Back to Review Listings

Do you manufacture or sell an LED flashlight, task light, utility light, or module of some kind? Want to see it tested by a real person, under real working conditions? Do you then want to see how your light did? If you have a sample available for this type of real-world, real-time testing, please contact me at

Please visit this web page for contact information.

Unsolicited flashlights appearing in the mail are welcome, and it will automatically be assumed that you sent it in order to have it tested and evaluated for this site.
Be sure to include contact info or your company website's URL so visitors here will know where to purchase your product.

WHITE 5500-6500K InGaN+phosphor 
ULTRAVIOLET 370-390nm GaN 
BLUE 430nm GaN+SiC
BLUE 450 and 473nm InGaN
BLUE Silicon Carbide
TURQUOISE 495-505nm InGaN
GREEN 525nm InGaN 
YELLOW-GREEN 555-575mn GaAsP & related
YELLOW 585-595nm
AMBER 595-605nm
ORANGE 605-620nm
ORANGISH-RED 620-635nm
RED 640-700nm
INFRARED 700-1300nm
True RGB Full Color LED
Spider (Pirrahna) LEDs
True violet (400-418nm) LEDs
Agilent Barracuda & Prometheus LEDs
Oddball & Miscellaneous LEDs
Programmable RGB LED modules / fixtures
Where to buy these LEDs 
Links to other LED-related websites
The World's First Virtual LED Museum
The Punishment Zone - Where Flashlights Go to Die
Legal horse puckey, etc.
LEDSaurus (on-site LED Mini Mart)

This page is a frame from a website.
If you arrived on this page through an outside link,you can get the "full meal deal" by clicking here.