twhitehouse
Newly Enlightened
- Joined
- Aug 27, 2010
- Messages
- 16
This is probably the wrong subforum, but its close in my mind as I intend to do this with an LED...
My searching skills have failed me again, I need to know about aspherics!
Well, actually, I need to know exactly what is meant by focal length. My basic understanding is that if an aspheric lens is measured as, say, 50mm x 20mm, that it has a 50mm diameter, and is 20 mm from the back flatside to the top of the front curved part, at its thickest point. Now, lets say it has a defined focal length of, 5mm. That is to say that the best point for focus and long throw would be an LED mounted 5mm behind the lens' back, flat end, is it not? Logic tells me that makes sense, but I'm finding it difficult to find a definitive answer.
Also, as an aside, I see many uses of "M@G" or "M*G" in place of "Mag" when referring to Maglites... is it considered impolite, or some other etiquette to use the trademark? I've posted a few times about modding Maglites, and no one has corrected my spelling or useage, but I think I may be missing an unspoken rule here at CPF regarding them...
Anyway, I thought I'd ask because I want to do an XR-E Mag mod, and I'd love to convert one of those cheap, plastic 6V lanterns into an XR-E with 3inch aspheric and a big ol' battery behind it... (heat management is my only issue right now on that one, and I think I may have it figured out...)
I'd also love to do about a half dozen other flashlight mods, all planned out on paper so far, with previous flashlights I own, but alas, finances do not permit for this.
Thanks for the info on focal length, aspherics in general, and the M@G issue.
-Whitehouse
My searching skills have failed me again, I need to know about aspherics!
Well, actually, I need to know exactly what is meant by focal length. My basic understanding is that if an aspheric lens is measured as, say, 50mm x 20mm, that it has a 50mm diameter, and is 20 mm from the back flatside to the top of the front curved part, at its thickest point. Now, lets say it has a defined focal length of, 5mm. That is to say that the best point for focus and long throw would be an LED mounted 5mm behind the lens' back, flat end, is it not? Logic tells me that makes sense, but I'm finding it difficult to find a definitive answer.
Also, as an aside, I see many uses of "M@G" or "M*G" in place of "Mag" when referring to Maglites... is it considered impolite, or some other etiquette to use the trademark? I've posted a few times about modding Maglites, and no one has corrected my spelling or useage, but I think I may be missing an unspoken rule here at CPF regarding them...
Anyway, I thought I'd ask because I want to do an XR-E Mag mod, and I'd love to convert one of those cheap, plastic 6V lanterns into an XR-E with 3inch aspheric and a big ol' battery behind it... (heat management is my only issue right now on that one, and I think I may have it figured out...)
I'd also love to do about a half dozen other flashlight mods, all planned out on paper so far, with previous flashlights I own, but alas, finances do not permit for this.
Thanks for the info on focal length, aspherics in general, and the M@G issue.
-Whitehouse
