thermal imaging / standard optics

[ivymike]

hey, does someone know whether the sensor below

http://www.google.com/products/cata...=X&ei=YuStTdfWJczqgQfvte2HDA&ved=0CB4Q8wIwAA#

can be mounted behind & work with an optical (glass element) rifle scope?

 

[btrueblood]

Ivy,

A rifle scope (or any refractive glass optics) will have a slightly farther field of focus for IR compared to visible. As long as you can adjust the focus of the camera, or its distance behind the scope, it should work. Next problem would be whether you get enough field of view in the camera to make a workable image for seeing whowhat you are shooting at.

 

[IRstuff]

Sorry, no go.

The camera cited is a "thermal imaging" device. That particular version is an uncooled long wavelength infrared camera, sensitive to 8 um to 12 um, or thereabouts. The typical riflescope will cut out short of 2 um.

Now, if you hang something like this:

http://cgi.ebay.com/FLIR-Inframetri...Television_Test_Equipment&hash=item255b3085a0

in front of the camera, you may have a shot...

TTFN

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[LionelHutz]

Agreed, the camera will not "see" anything through a normal rifle scope.

 

[ivymike]

hmm... so my goal would be to have a weather/shock resistant thermal imaging sensor which could be used with or without a scope. Sounds like a special scope would be required. Any idea where such a thing might be found?

 

[btrueblood]

Um. In the near-ir range, a typical glass-optic scope would work.

For true thermal IR imaging, IRstuff is right, glass won't transmit the longer wavelengths, you need optics of CaF2, germanium, ZnSe, or similar materials. Google "long ir optics", one of the hits will be ophiropt.com who claim to make lenses for lots of camera brands.

 

[KENAT]

I'd look at military surplus, or perhaps the military's suppliers.

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[IRstuff]

For a reasonable resolution at 100 yds, you need something on the order of 10ºdeg FOV, so something like this:

http://www.amazon.com/Thermal-Eye-I...FK/ref=sr_1_33?ie=UTF8&qid=1288975111&sr=1-33

This one is a lot cheaper:

http://www.amazon.com/ATN-X150-Ther...PW/ref=sr_1_23?ie=UTF8&qid=1288975111&sr=1-23

but the IFOV is quite large, since the GSD is pushing 6.7in at 100yd.

This one might also do:

http://www.amazon.com/ATN-ThermoVis...TD0A/ref=sr_1_5?ie=UTF8&qid=1303323031&sr=8-5

GSD is about 3.6in at 100yd

One caveat is the sensor resolution. The most expensive one listed above uses a 320x240 array, while the other two have 160x120 arrays.

TTFN

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[ivymike]

I'd love to have the $12k one, but it seems like it would also be nice to be able to pull it off the rifle and change FOV (to follow a warm blood trail, for example) without having to recalibrate/align upon reassembly. Would also be nice to use for obstacle avoidance in the car (as w/original link). Hence the question about using w/standard fixed scope.


The $2500 one I originally linked to is 320x240 resolution, but has the wrong FOV for hunting. (right for following a trail or dodging bunnies)

http://www.atncorp.com/atn-thermal-securitycamera-flir-pathfindir-30

 

[KENAT]

How about, thermal imager with red spot projector for your spotter, then you can use a standard scope?

Might fudge the rules a bit about having clear view of your target etc. though.

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[Ron]

I have a FLIR thermal imager and the manual implies that no supplementary optics can be used in front of the imager lens.

 

[IRstuff]

That's IF you have a full imager, which the PathFindIR is. However, the PathFindIR FOV is 35° x 27°, which is way too big to do any serious rifle work. You would have to remove the existing optics and attach a narrower FOV optic.

TTFN

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