Whitening beam in old ARC LS 1st Run?

I have one of the original ARC LS first runs. It has a green cast to the beam. What would you afficionados suggest I do to get a nice white and bright LED in it (and how much $$?).

Thanks. /ubbthreads/images/graemlins/wink2.gif

You want to mod it? Be more specific ,please.

he doesn't want to mod it...he's already specified that he'd like a whiter and brighter LED to replace the greenish LED in his arc LS.

Well, that would require a mod, a new high dome LS.

Figure ~$15 for a LS, and whatever somebody like LitFuse charges for switching out the LED. You could get the mA bumped up while you're at it, for more brightness, but it will hurt (or kill, depending) your runtime.

I've never done a "First Run", but I've heard that the LED is potted in epoxy. If this is true, it wouldn't be worth the hassle.


Peter

If its a first run it is volt regulated and is topped out on power but I just changed the led in mine to a q3h lowdome its a whole different light now. circuit is potted led wasn't. centering was easy.
Chris /ubbthreads/images/graemlins/grin.gif

Try having the inside of the lens coated or a tinted lens fitted by Lenscrafter or other eyeglass maker.

I've experimented with plastic CP (color printing) filters and found that a .10M (magenta) filter cancels almost all of the green tint on my LS. However, mounting a filter on or inside the lens would look crappy (newton rings and/or reflective loss from a double surface), so I'd look into having it coated or replaced by a new tinted lens. Downside: about a 10% loss in brightness and high cost.

Another thought: try tinting the inside of your LS with magenta or reddish marker. This would take some experimentation, but might be the cheapest route. Hmmm..or spray the inside of the lens with a transparent red/magenta paint or even applying a red dye solution to the inside surface.

Perhaps Peter could find a way to offer tinted replacement lenses.

BTW Sotto: I live in Venice, southwest of SM Airport. Probably just a few blocks away. I could loan you my set of Ciba Color Printing filters to measure how much color correction you need.

Chris:

Would you mind giving me a thumbnail overview about exactly how you changed your LED and where you got the LED (how much $, etc?)?

Thanks.

Rodmeister:

Yes, I'm probably not far from you (south S. Monica), and thanks for the offer, but I'm more interested in pursuing the LED change idea at the moment.

sotto /ubbthreads/images/graemlins/thumbsup.gif

Hi , I've hit on a cheap trick for 'correcting' unpleasant LED color casts- thought I might share.
1- You cannot perfectly correct a cast
2- Any correction through filtration automatically results in a loss of light, measued any way you like- Lumens, Lux or CPS.you will loose photons in the process.
3- Color Correction filters (CC) work but are awkward to use in flashlights
4- Drum roll please....Introducing...The ubiquitous SHARPIE Fine Point Permanent marker ! Before you write this off as crazy. It's cheap, removable ( Denatured alcohol, or after-shave) and because it's on the LED emitter's lens, is completely unobstrusive. Now the fun part...WHICH Sharpie colors work?
5-For nasty ol Nichia LED's I use the ORANGE sharpie for what I describe as a 'Faded Starawberry' Hue. Before you scream..remember what I said about light loss? It happens that you will lose about 20% of the light BUT it will be twice as easy for you to distinguish objects in the dark in this wavelength. Sounds crazy but it isn't...in practice. This is because our eyes (and indeed most lenses) have trouble focusing light in the Blue end ot the spectrum (ask me for more details on this)..and yet, even with less actual light, our eyes can focus more easily in the Red end of the spectrum. This Strawberry hue is between Orange and Red- a nice sweet spot.I've done this trick to my SL TT2L (Cyanish Nicia's) and it works perfectly! I've not had the priviledge of owning an ARC Luxeon first run or other greenish/yellowish Bin lights- so I can't recommend a Sharpie color but I would guess that either the Red or Magenta Sharpies would work. Remember, you are replacing a nasty cast with a less nasty & more useful one.For a more accurate shift, CC filters or professional tinting would be best. Theoretically, a light Magenta tint woould work- CC5M or CC10M.In practice, LED color is not the same as incandescent- for which CC filters were designed. Trial & error tweaking is indicated here. /ubbthreads/images/graemlins/banghead.gif

Sotto
Unscrew the bezel carefully,push the pcb straight up from bottom of head,it may have some epoxy around board.
Mark or somehow identify positive side of emmiter (long extra tab on leads) unsolder leads,the emitter on mine was secured with a pliable putty or soft epoxy that with a little pulling and pushing (gingerly) it came loose.With a small plastic scraper carefully remove all traces of sink compound (don't scratch gold foil traces).I used one part of my AS epoxy because it gets slightly thick in time (and I ran out of AS compound) and I wanted to be able to replace the emitter again. Solder the leads down to the pads using pressure on the emitter to keep it tight to the board It dosen't get a whole lot of heat sinking in this design but its not being pushed very hard either.try and get it back in the same position (if your leads have not been cut lining the leads up with the pads closely should center it good for a low dome,a high dome might be harder to center) I buy my led's from whoever has the ranks that I want.Dat2zip,Electrolumens,Arcmaina (thanks Mike) and others.(BST)anywhere from $10 to $30 for a 1 watt.
Have fun
Chris /ubbthreads/images/graemlins/grin.gif

Thanks very much, Chris.

sotto

There was someone posted awhile back about sticking some "photogreen"(?) camera lens color filtering film on it and I did try it on a poorly colored example I had laying around (this kind gentleman sent me a sample and I apologize but I cannot for the life of me remember who it was) and I'll be danged if it didn't make the beam completely white. Completely. There was a detectable loss in output to the eye though, but not much. Also it comes in different strengths (shades) for coloring different green-esses...

How comes?, I'd tested my Ls current consumption with the tester and only runs 275 mA, the battery is at 3.0v exactly..