I remember seeing some discussion about certain LEDS not being positioned correctly to be focused by the the reflector. Which LED is the host best for out-of-the-box currently? Looking to get an L21B without having to mess around with spacers.
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SFT40 is the easiest to center and has greater tolerance than smaller LEDs. Ideally ask Simon for square-hole gaskets.
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I was wondering more about “focus” where the depth of the led within the reflector is adjusted to change the beam characteristics.
Larger die LEDs have a greater range of heights where the focus is ok. Hence the mention of tolerance.
Ah ok. Centering could also be referred to in terms of tolerances too though, no?
Yes; larger dies have more tolerance in both focus and centering, due to being worse approximations of a point source. Sorry for the ambiguity!
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I assume this translates into “it’s easier to get a “good” beam with a large LED than a small LED”? TIA
Yes. Larger LEDs require less precision on the part of the secondary optic, including the focusing and centering.
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I have purchased L21B SFT-40 5 times and first 4 was excellent but this last have some problems.
It is first time that I get L21B with black gasket with round hole, first 4 was with white gasket with square hole.
In this last L21B led is not good centered and beam and throw is bad.I get it with very loose bezel.
After 3-4 attempts I centered it better and situation is now better but far from ideal. Hotspot is not perfect circle like my other L21B and corona have iregular shape. On small distance under 1 meter I have black hole in hotspot.
I think that diameter of hole in gasket is larger than diameter of led and gasket is thinner than on older L21B. In reflector I have a multiple specs of dust which is not problem for me, but my old L21B which I use many times for last 2 years don’t have any dust inside.
I wite to Simon about this problem and ask if I buy and exchange with old type white gasket will it correct situation. He answer that using white square hole gasket cannot solve problem because problem is with macchine processing reflectors and that I remind him to send me reflector from new improved batch.
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I think you are right about the problem being the round-hole gasket–they simply don’t work. The dust in the reflector is probably from the LED corners scraping the gasket.
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I believe SFT40 is a right choice.
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So if I add a note to my order Simon will hopefully solve the issue ahead of time. Thanks for sharing your experience.
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I will ask Simon to send me new reflector and gasket with my next purchase from Convoy store.
I will write about results when I receive it.
But I must say thay L21B even with this bad gasket and reflector has remarkable throw, biger than I need in practical use.
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