Thermal lenses

[rodp]

Apparently this is what the Iphone thermal lens is made of, supposed to be a much cheaper alternative to germanium ? It can be ground as normal glass, so it says, so may bring thermals down in price.

http://www.us.schott.com/advanced_optic ... e-glasses/

[rodp]

No-one know anything about them ?

[sunndog]

I'v read about different materials that can be used. But I'm hardly up to speed on such things.....for me, when I start to see them used on thermal units that I can relate to I'll take notice

[andybig]

I know they are using some sort of alternative moulded lens material in the Flir One and the Seek thermal gadgets that attach to your mobile phone.
I think its a case of wait and see who the first company to use bigger versions of this type of lens.
I should imagine they are all looking at it.
But the first company to put these into production will rock the industry.
I should imagine the big boys have a lot of cash tied up in germanium lenses.

[phoenix]

I think we'll start seeing lenses made from Chalcogenide glass in hunting thermals at some point - the big advantage with it is that it can be moulded to shape rather than machined from a single crystal.
ATM it seems they're concentrating on making small lenses since that's where most of the market is.
Whether they can be accurately manufactured is the sort of sizes we would need (38mm and larger) is open to question.

Cheers

Bruce

[andybig]

This is probably a question to Bruce.
When you say 38mm and larger.
It that 38mm thickness or diamerter.
Iv got no idea if they work in a different way from a normal lens apart from allowing the Ir wave length for thermal sensors.
The reason i ask that they state they can make lenses up to 30mm thick and 100mm in diameter.
http://www.us.schott.com/advanced_optic ... e-glasses/

[phoenix]

Thermal lenses are normally specified by focal length and aperture, so 38mm means a focal length of 38mm.
Most thermal lenses have low f numbers, typically between 1 and 1.4
For example the lens on the Pulsar HD38s has a 38mm focal length and an aperture of f1.2 which means that the actual diameter of the lens is 31.7mm (38/1.2)

Cheers

Bruce