Dedoming XR-E R2 in aspheric Solarforce L2 for more throw?

Blitzwing

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I've got an L2 that I use as a hunting light, with the 26mm DX glass aspheric lens, blacked out reflector and stock single mode Solarforce XR-E R2.

This throws OK.

I have a spare dropin and was wondering if I dedomed the emitter would I get a tighter beam and thus a bit more throw?

I've done some searching but answers seem scarce or ambiguous. I'd rather not wreck a spare dropin for little visible benefit or to it's detriment.


Cheers.
 

2xTrinity

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I've got an L2 that I use as a hunting light, with the 26mm DX glass aspheric lens, blacked out reflector and stock single mode Solarforce XR-E R2.

This throws OK.

I have a spare dropin and was wondering if I dedomed the emitter would I get a tighter beam and thus a bit more throw?

I've done some searching but answers seem scarce or ambiguous. I'd rather not wreck a spare dropin for little visible benefit or to it's detriment.


Cheers.

By De-doming a modern LED you'll end up with a narrower beam but it won't be much (if at all) brighter, you'll just be making your system less efficient overall. The hemispherical domes help to capture a significant amount of the light from the LED which would otherwise totally internally reflect and be trapped inside the LED.

What I'd expect is you'll have maybe 10-20% peak intensity/ lux incident on your target, but you will be illuminating a MUCH smaller area overall -- meaning your total output in lumens will drop precipitously (~40-50%).

That may actually be an acceptable tradeoff for you if you're trying to look at something far away, and a wider beam (with more lumens) causes more stuff in the foreground to be lit up, reducing the apparent contrast between your intended target and the closer surroundings. But be aware there will be a dramatic loss in efficiency.
 
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srfreddy

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sigh....this isn't true. LED domes focus the light forward and narrow the angle of emmition. Projecting more light forward, the lens puts more light into your aspherical lens. In reflectors, the larger angle from de-doming increases the amount of light hitting the reflector, increasing throw.
 

bshanahan14rulz

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srfreddy, you can try it and see if you'd like. When you remove the tiny glass dome, you get lower overall light output, but the die appears much smaller, and thus easier to focus for the next optic, be it reflector or aspheric. I've only dedomed 2 LEDs, one on accident, but the other was an XR package. I removed all gel and the metal ring, and applied a flat coat of NOA61. As it turns out, NOA61 is a very poor choice, it turned yellow from the heat. But I did notice a smaller hotspot with a P60 reflector, and a smaller image when focused in a spare projector optics barrel.

Personally, the robustness (if you can even call it that with these delicate powerhouses) of the LED outweighs the benefit of dedoming, in my personal opinion. However, if you have a backup LED, then hell, might as well!
 

allburger

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By de-doming, your tint will go towards a green tint as well. I had a dedomed xr-e a few years ago and that thing threw like crazy with the orange peel reflector.

The problem with dedoming is that it's not as durable.
 

D3rtyH3rry

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Ok, I'm new here, but I have to ask why the tint gets greener when you dedome?
 

saabluster

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Part of the phosphor will be removed along with the dome.

Norm

While it may be true that some phosphor could be removed when dedoming that is never the cause of the tint shift. Not to green anyway(a blue tint shift can happen with removal of phosphor). It is caused by more blue light being converted due to internal reflections which are caused by the drastic change in refractive index without the dome.
 

bshanahan14rulz

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What is throw? Is throw the flashaholic term for divergence, or does it mean some arbitrary ratio of divergence to lux, or what?

I thought your original answer sounded fine, unless by reducing throw for aspheric setups, you mean that while the hotspot will be smaller, the lux will have dropped enough that the increase in lux from a smaller hotspot does not overrule the loss in output from dedoming
 

ma_sha1

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What is throw? Is throw the flashaholic term for divergence, or does it mean some arbitrary ratio of divergence to lux, or what?

I thought your original answer sounded fine, unless by reducing throw for aspheric setups, you mean that while the hotspot will be smaller, the lux will have dropped enough that the increase in lux from a smaller hotspot does not overrule the loss in output from dedoming

I am referring to hotspot lux only

Where did you get that idea ma_sha1? Dedomed LEDs increase the throw in both applications.

Remember Ra & Dr. June's threads & experimental proof? In aspehrical set-up, Adding secondary lens infront of led does not change throw. Removing the dome, which is a secondary lens, does not change throw if the led remains unchanged. But in this case, after de-dome, the led lose about 30% brightness , thus lose throw.
 
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srfreddy

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I remember reading that thread. However, the xr package lens has different optical properties than the xp package...
 

Luminater

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I have many dome , dedomed , reflector , aspheric lenses flashlights, and tested.

LED domes = narrow beam = good for aspheric lens.
LED dedomed = wide beam almost 180 degree = reflect to reflector, increase throw = good for Throwking Reflcetor.
 
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