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IR & Greenies

Hemlock_Mike

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Someone over on CPF got me thinking - a dangerous proposition for sure  ;D

The Newish style pointers have a "nose piece" almost a half inch long and with a small exit port.  Since IR leaking past the MCA is diffused, wouldn't this space act as an attenuator causing the IR to assume a "Lost in Space" condition ??  Almost a filter chamber.  Perhaps this is why many of these "cheap" pointers appear to have low IR output.
Sometime we need to remove that "nose piece" and remeasure to confirm.  IR out with and without its nose :eek:

Mike
 



S

SenKat

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I hav a "naked" DX 50mw sitting here......... IF I get time tomoorw or Friday, I wil take a peek at it, to see what the measurements are, that is an interesting idea ! BUT I know for a fact, from dissasembly that they have IR filters (The Newwish style) but will try the test any ways :)

G !
 

Hemlock_Mike

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I agree -- I see what should be a filter there too BUT if it's not too good, the NOSE may help by capturing stray IR. I still haven't found a DX with "TONS" of IR emitted.

Mike
 

Things

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the DX 20 and 30 that i ripped apart didn't have any apparent IR filter, but there was a blueish beamsplitter thing, so maybe it was a beamsplitter and IR filter in the same piece of glass?
 

pseudonomen137

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things said:
the DX 20 and 30 that i ripped apart didn't have any apparent IR filter, but there was a blueish beamsplitter thing, so maybe it was a beamsplitter and IR filter in the same piece of glass?
Hehe. That blueish beamsplitter thing IS the IR filter  :D. Its a cyan dichroic IR filter - the type normally used with greenies.


I think the IR filter is what is blocking most of the IR, althought that is an interesting idea. The exit aperture on the cap isn't particularly small though, and the IR wouldn't diverge so fast that most would hit the cap after such a short distance. Not to mention that the majority of the beam's power is near the center of the beam.

Then again, I haven't tested the idea, and it does seem likely at least a small part of the stray IR would be blocked. I'm doubtful it blocks more than a minority of the stray IR though.
 




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