11/30/2009: Out door shots, before & after, are up on post #16
This is an improvement effort on the Kel-lite SSR-90 I build a short while ago:
http://www.candlepowerforums.com/vb/showthread.php?t=238232
The LED was from the very top Bin, Neutral Tint: SSR-90 57K, GN201.
A few weeks ago, I took this light out for Halloween Trick-or-treating with my kids, there's a lot of people out with flashlights, mine was the brightest by a landslide. The light has so much spill that I blinded two old ladies with the spill, I wasn't even pointing the light at them.
So I thought, wouldn't it be great if I can harvest some of the mid range spill and apply it towards the center of the beam? I am not talking about typical aspherical, as I still want a round hot spot & I still want some spill, especially the immediate spill right next to me is necessary to light the walking path. I came up with some ideas, this is what I wind up doing: Duracell Daylight concept applied to a much more powerful flashlight.
First, I mounted a small aspherical lens on top of a spring, the diameter is about the same as the
flat bottom area of the P7 reflector I used:
The idea is, it collect the light that escapes the reflector (The spill) only & send them to the center.
But it does not cover the reflected light path!
This is important, as if it does (if lens is too big), you'll get messed up beam.
When you screw the bezel on, the flat lens press the aspehrical lens in place so the whole set-up
stays put & looks normal from out side.
With this set-up, you could get two distinct hot spots from a single flashlight if they are not aligned well,
obviously, I am not trying to make a dual hot spot flashlight
. However, I might be be the first one who produced dual hot spot from a single die
A little better, but this lens didn't work out, as it gives a square hot spot similar to regular aspherical
when aligned. This is not what I want, otherwise I would have gone to 52mm Aspherical lens to begin with.
Played with different lens, this this the result I wind up settling with:
The Corona is produced by the small aspherical lens & diffused.
It overlaps with the round reflector hot spot & corona making both brighter.
It rubs from medium distance spill & you can see the dark ring around the corona as a result of spill stealing.
The ceiling bounce beam shot takes a bit to get use to, as you don't see this type of set-up in flashlights,
but at a distance, you can start to appreciate the practicality of this set-up.
At about 15 ft, the field of vision where you are looking (the door) & it's surroundings are lit up by the SSR-90 Jumbo hot spot & Corona, the dark void can be seen only far out next to the light switch, which is out of your viewing zoon already, You don't even realize it's there.
This way, next year trick-or-treating, I can direct the beam away from people & place them off the Corona into the dark zoon, therefore minding my own business by pointing the light where I want it to be without disturbing people in the surroundings. Especially, at longer distance, 50-100ft, the dark zoon will become quite large & becomes practically useful.
I wish there's a 52mm TIR for SSR-90 I can just purchase , I basically hand made a TIR type of beam, with may be some extra spill at my foot.
This set-up does not reduce the spill towards the immediate surrounding, so I can still walk a bright path.
The immediate spill is produced from the gap between the edge of aspherical lens & the reflector path.
Another beam shot, down the stairs
One last beam shot, if you look very hard, try change the angle you are looking at the screen, you can see the
blending of two beams that forms the corona. Slightly yellower shade from reflector & slightly whiter
squarish shade from aspherical lens.
One last frontal shot, I think it looks pretty cool.
The end.
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