Cereal_Killer, OnetrickPony and Dave_,
Thanks,
your packages are ready and will be shipped on Monday.
current stock:
25mm: 9
38mm: temp. out of stock.
50mm: 35
Darn, I was just about to decide that I need 1 or 2 38mm ones…
I’m getting some more, I’ll let you know when I have them (probably in 1 or 2 weeks).
do you leave the reflector in the head when swapping the glas with a lens?
A conical reflector might be good
Please do!
I’ll keep my eye on this topic as well.
I typically don’t use a reflector when using a lens. light that hits the reflector will not go through the lens correctly and the lens will not focus the light but just image it somewhere else. this basically destroys what the refector did, namely focus the light that hits the reflector properly.
one way could be to use a reflector that is bigger than the lens and use the lens to focus the light that otherwise would not hit the reflector so also that light gets focussed. This is however quite a tricky setup since you need a way to properly mount the lens inside the reflector and properly centered.
The reason I’m offering only short focal lengths, compared to their diameters, is to capture most of the light so I would not need a reflector. In some applications you also don’t want a corrona around the hotspot. In that case, it is better to make the walls black and have a sharp spot from the lens with no light around it.
regards,
Johan
With a conical reflector the reflected light still has ( more or less) the same direction, so it would end up in the same area, somewhat.
But I think we would need a nice little positive meniscus aspheric lens as primary optics, so that ALL of the emitted light will hit the secondary lens.
That makes the hotspot bigger, and not brighter, that could be what you are after of course, in fact it the emitter-dome does some of that already.
I thought it would add to the total output.
You’re right.
Hey man just lettin you know my lens got here today, just one week from EU to USA with non-tracked shipping over a holiday. Thanks.
And BTW it turns out this lens is less than 1mm larger than I need so it should be pretty simple to shave it down to size.
Received two 50mm lenses today, these things are really cool, tried with an mtg2, they seem somewhat more forgiving than aspherics when defocused, way less ringy and fewer artifacts.
Note: it seems so far that decreasing the focal length is by far better than increasing it if you are trying to get a floodier beam, if you go farther away from the led beyond perfect focus the color gets very strange, I’ll try to post some pics when it gets dark out.
Thanks, jspeybro!
Not sure why having a short focal length would be better than a long one in defocusing an LED for floodbeam.
My current EDC has a long focal length aspheric. It’s a fairly flat 21mm lens with around a 20mm focal length. I’ve tuned the zoom so that in flood mode the lens retracts until it’s within a couple mm of the top of the dedomed LED. The resulting flood is completely uniform with no hotspot and no rings outside the hotspot. It also gives an extremely wide 90 degree beam angle.
If you want a floody beam, I think making sure the lens sits as close as possible to the LED is more important than the focal length. That said, I have some 15mm focal length fresnel lenses on order so when they arrive I’ll be able to compare.
You’re right, I was only talking about the distance to the led, not the focal length of the lens itself.
I’m just curious about how much lumen loss are you guys experiencing when zoomed all the way in with these? I’m loosing so much overall light that throw is really suffering. Driving an XM-L2 U2 1A at 3A with >2.5oz of copper for the pill (custom build) I’m not even able to throw 100m (sorry I don’t have a meter yet, it’ll be here Monday and start a thread about it then). Tomorrow I’m going to dedome the emitter but I doubt that will magically make it great or anything…
I had really high hopes for this light, by spec’d it should be a laser beam and super bright, do I just need to crank it up?
Also is it recommends to paint the inside of the had black to reduce spill beam artifacts or white to increase overall brightness or what are other people doing?
I used matt black heater spray paint for a sk68 mod, here:
I tried some things with a tiny white reflector, to add some spill to the output.
Didn’t do much good in practice, because it was a messy spill.
If I want spill, I zoom out.
Try to get the lens as close as possible to the LED, gives a big wide circular beam / flood.
Nice.
I don’t like the idea of deliberately wasting light by painting stuff black, but it can make things better sometimes.
The thing is, I can’t zoom out, this is a fixed focus thrower, not a zoomie. I’ve currently got the inside of the spacer wrapped in black electrical tape but I’ll probably paint it flat black whenever I remember to pick up some black paint to see what that does, I’m hoping to eliminate most, if not all spill beam outside the square hot spot.
Any lumen loss estimates from being fully zoomed? Opinions on dedoming the emitter [XM-L2]? I built it with an XM-L that was dedomed white I waited on my Noctigon’s but now that I have the XM-L2 in it with the dome back not sure I could tell a difference.
Hi Guys,
the 38mm lenses are back in stock.
Johan
up 