Electronics, Lighting, & Gadgets - Can I mod/use a FENIX as a rear light?

I think this has been covered before, but I don't remember the thread -

I LOVE my Fenix L2D for front lighting. It's incredibly convenient, bright enough to ride well, and I love the lack of wires and pocket size.

I love the turbo strobe as well, and think it would be perfect for a bright rear-light, however, I think it has to be red to really work well.

Are there any easy ways to mod the FENIX to get it red while keeping the intensity? Or is there something inherently bad about trying the FENIX in the rear? (Wow that last sentence came out wrong....)

turbo strobe can cause seizures, I'm sure.

www.brightguy.com sells a red filter for the fenix. I don't see why it wouldn't work.

A red filter or red lens is the way to go. Maybe the link above will work? If not then some of the red transparencies used for AV lighting should work, just cut out the shape of the light and tape/glue it on.

I'm sure the red filter is for when you want to use it as a night light that won't ruin your night sight. not that it won't work for a tail light application. but the turbo strobe is fast enough to induce seizures.

The Fenix's strobe mode is not suitable for taillight use, red or otherwise. It's a 10Hz tactical strobe intended to disorient people, and at the very least it would be irritating. Also, the red filter will cut your light output severely (I have one).

It would be nice to see Fenix make a proper bicycle taillight, though. Something with a red emitter, a turbo head (larger diameter), a super-flood beam pattern, and a civilized flashing pattern a la DiNotte.

I really wish people wouldn't keep repeating the unsubstantiated meme that flashing lights are enough to cause photoepileptic seizures in anything above an exceedingly small fraction of the population. It really only takes a few minutes of googling to actually understand how light-sensitive seizures occur, and how rare they are. Saying "I don't use the strobe because I don't want to cause seizures" is about as logical as saying "I don't use the horn in my car because I don't want it to keep me from hearing a passing train as I ride over the rails." It really doesn't make any sense at all.

we don't want to disorientate drivers behind us either, now would we?

it is easier to judge distance with a solid light over a blinker. pair up a solid and blinker to allow drivers to see you and judge your distance.

Your idea sounds good in theory but you might as well just get a couple Planet Bike Superflash.

You lose a lot of intensity putting a red filter over a white LED, which has very low red in its spectrum. And the strobe effect is too dazzling - it actually makes it difficult to gauge distances. Yeah, they see you, but they'll have no idea how close/far you are.

You lose a lot of intensity putting a red filter over a white LED, which has very low red in its spectrum. And the strobe effect is too dazzling - it actually makes it difficult to gauge distances. Yeah, they see you, but they'll have no idea how close/far you are.

I think that's an overstatement. At least, I have no unusual difficulties gauging the range of a flashing blinkie just because it flashes, and it does get my attention far better than a steady light that could easily blend into the scene. Given the certain improvement of getting noticed, versus the dubious benefit of providing a better range cue, I'll take getting noticed. I provide range cues by other means anyway... divergence cues by the horizontal and vertical separation of multiple taillights, for example, and lots of reflective material to give me a large visual profile as the viewer gets closer.

I thought that would be the case with the LEDs - with low red light in the spectrum.

I already have a PB superflash - great during the night - not so good during the day (unlike the FENIX which is definitely excellent during the day.)

I thought that would be the case with the LEDs - with low red light in the spectrum.

I already have a PB superflash - great during the night - not so good during the day (unlike the FENIX which is definitely excellent during the day.)

A neon-lime ANSI Class II/III vest makes a good daytime visibility booster for pretty cheap. If you're into do-it-yourself projects, a Whelen TIR3 or Nova BULL strobe head would give you DiNotte-level power for less money. Wire one up to a 12-volt battery and figure out a mount for it, and now you're cookin' with gas :thumb: Definitely daytime-visible in direct sunlight for hundreds of meters.

Don't bother modding any flashlight for taillight use. Not worth it. It is very rare for strobe light to cause seizure, think Police and emergency vehicle, how often do you hear of anyone going into seizure due to those? PB Superflash does suck during daytime. Verified on a cloudy day with fresh battery.
It's a 10Hz tactical strobe intended to disorient people, and at the very least it would be irritating. 10hz strobe is fine. 10hz is standard flashing for emergency vehicle. It certainly is irritating, as long as it gets drivers' attention, the job is done.

10hz strobe is fine. 10hz is standard flashing for emergency vehicle.

Where are you getting that information? See http://en.wikipedia.org/wiki/Emergency_vehicle_lighting#Potential_hazards .


Photosensitive epilepsy - This is an epileptic reaction to flashing lights in susceptible persons, which can range in severity from an unusual feeling or involuntary twitch to a generalized seizure. This epileptogenic response can be triggered by lights flashing in the frequency range of 10-20 Hz, regardless of color. While individual light sources used on emergency vehicles generally have much lower flash rates than this...

In the bigger picture, if someone is riding in such dangerous conditions that they'd need something as obnoxious as the Fenix's strobe mode, I'd suggest they get a Nova BULL for roughly 8 times the visible lens area and roughly 5 times the power output (since it's available with red emitters). Or a DiNotte if they want an off-the-shelf turnkey system.

Where are you getting that information? See http://en.wikipedia.org/wiki/Emergency_vehicle_lighting#Potential_hazards .




Harding, Graham F.A.; Peter M. Jeavons (1994). Photosensitive Epilepsy. London: Mac Keith Press, p. 163. ISBN 0-898683-02-6. "neither car indicators nor flashing warning lights on emergency vehicles constitute a risk, as they are restricted to 2 f/s or less"

A source from 1994. “2 f/s" I've seen my local emergency vehicles in action, they are certainly not 2 hz, they are not even 5 hz (I have a Dinotte-equivalent light strobing 5 hz, it's no where near the strobe speed of emergency vehicles).

The source is referring to these rotating strobe lights, newer model police cruisers and emergency vehicles do not use this anymore.

http://upload.wikimedia.org/wikipedia/commons/thumb/d/da/Lightbar_close-up_to_see_mechanism.jpg/800px-Lightbar_close-up_to_see_mechanism.jpg

Most of them are upgraded to LED systems.

http://www.extremetacticaldynamics.com/catalog/images/led_front.jpg

In the bigger picture, if someone is riding in such dangerous conditions that they'd need something as obnoxious as the Fenix's strobe mode, I'd suggest they get a Nova BULL for roughly 8 times the visible lens area and roughly 5 times the power output (since it's available with red emitters). Or a DiNotte if they want an off-the-shelf turnkey system.

I read up on the Nova Bull, specs says 3 x 1 watt LEDs, and no specification on lumens per watt either or LED specification. Haven't seen it in person, but on paper, not very powerful.

FYI, Dinotte 140L is 140 lumens at nearly 5 watt. For those reading thinking higher watt is better, higher watt doesn't mean squat, just as lumen per watt doesn't mean squat unless the light is directed where you want it to.

I read up on the Nova Bull, specs says 3 x 1 watt LEDs, and no specification on lumens per watt either or LED specification. Haven't seen it in person, but on paper, not very powerful.

Have a look, then: http://www.youtube.com/watch?v=k3cy6KSr8wk That little steady red light mounted above the BULL is a SuperFlash, by the way. In my judgement, the Nova is more potent than my DiNotte 140.

http://i240.photobucket.com/albums/ff237/mechBgon/BULL-1.jpg



FYI, Dinotte 140L is 140 lumens at nearly 5 watt. For those reading thinking higher watt is better, higher watt doesn't mean squat, just as lumen per watt doesn't mean squat unless the light is directed where you want it to.

Glad you brought that up. The BULL happens to have a fantastic beam pattern, a well-defined horizontal bar spanning a wide angle of approach. Also, I can vouch for its strobe patterns being nowhere near the rate of the Fenix, unless you count Deciblast. This is an emergency-vehicle light, btw. I usually run three-flash mode, which looks like the Cateye LD500 on a gigantic scale.

http://i240.photobucket.com/albums/ff237/mechBgon/bull.jpg


Bottom line: while my DiNotte and BULL have gotten nothing but compliments from motorists, I've heard of people being chewed out for running Fenixes aimed rearward in strobe mode, and also remarks from people who've considered it, done a reality check of what it would look like to a motorist, and thought better of their plan. If anyone still wants to run a tactical strobe as a taillight on their bike, I wash my hands of it.


For those interested in setting up their own Nova, see this thread (http://www.bikeforums.net/showthread.php?t=202062) for daytime visibility photos, mounting, etc. I currently run my Nova on a DiNotte 2-cell battery pack, and you can see how that was set up over at CandlePowerForums (http://www.candlepowerforums.com/vb/showthread.php?t=197538).

http://i240.photobucket.com/albums/ff237/mechBgon/bull.jpg


My dual led taillight is half the width of that, and yeah, still overkill by a lot. IMO, 10hz isn't tactical strobe, there's a mode above that, I believe it's a 12hz strobe with a half second pause, that's tactical strobe.
I haven't got any flak for using a 10hz strobe for most of the year, not from police either, though there was one instance where the police cruiser sped up behind me to see what I was, 10hz high powered LED strobe light at midnight does seem out of place.

From the video, the Bull operates at a 5hz strobe with a pause, is there no constant strobe mode? In any case, I won't be bothered with buying a Dinotte or the Nova Bull, what I have is already more than enough.

My dual led taillight is half the width of that, and yeah, still overkill by a lot. IMO, 10hz isn't tactical strobe, there's a mode above that, I believe it's a 12hz strobe with a half second pause, that's tactical strobe.
I haven't got any flak for using a 10hz strobe for most of the year, not from police either, though there was one instance where the police cruiser sped up behind me to see what I was, 10hz high powered LED strobe light at midnight does seem out of place.

From the video, the Bull operates at a 5hz strobe with a pause, is there no constant strobe mode? In any case, I won't be bothered with buying a Dinotte or the Nova Bull, what I have is already more than enough.

The BULL has eight modes:

http://www.strobe.com/images/stories/bull_fp.jpg

Note that the video, having been shot with a digicam, is not quite accurate. My camera is incapable of accurately portraying Deciblast, for example.