Very wide angle lens for TAU?

[hap2001]

Hi, is it possible to get a very wide angle (such as 90 degrees) lens for TAU 320, 25um pixel?
There was a 5mm lens in brochure, but that's for 160 only, means the image circle is too small.
I'm not afraid to modify / duct tape a lens in place, but I just cannot find one with both short focal length and big image circle.

[Fraser]

With only 3 complete pixels in every degree of horizontal view on a 320 x 240 pixel TAU, FLIR thinks such a lens HFOV better suited to a 640 x 480 pixel TAU and so only offers the 90 Degree HFOV on that version of the TAU. 90 degrees HFOV really is a wide field of view for anything less than a VGA sensor array. I have no doubt that a company like Ophir can provide such a wide angle lens for you to adapt to your TAU core, but it will not be cheap and the results may disappoint. FLIR do produce supplementary lenses for some QVGA cameras that provide a 90 Degree HFOV but these are often specialist models intended for viewing inside electrical cabinets via a view port.

The security cameras that I have worked with sometimes use a 90 Degree HFOV for wide coverage but they invariably use a 640 x 480 pixel core. The image detail that they produce is little different to a 320 x 240 pixel core that is fitted with a 45 degree HFOV lens when operated at the same distance. It is the need for a continuous view of a large scene that justifies the additional cost of the VGA thermal core.

Fraser

[hap2001]

Thank you very much Fraser.
I think Flir should be more open-minded, I remember saw a 47x47 imager with 120 FOV...

[Bill W]

The security cameras that I have worked with sometimes use a 90 Degree HFOV for wide coverage but they invariably use a 640 x 480 pixel core. The image detail that they produce is little different to a 320 x 240 pixel core that is fitted with a 45 degree HFOV lens when operated at the same distance. It is the need for a continuous view of a large scene that justifies the additional cost of the VGA thermal core.

Fraser

Indeed, it is too easy to think of higher resolution cores giving you greater resolution, when it can often be more useful to think of them giving you extra pixels around the edges.

An Argus P-type 640 being an extreme example, it only ever processed & displayed a 320x240 image.  The benefit was that at 2x zoom it used the middle of the sensor sensor 1:1 pixel, and out of zoom ran 2x2 binned (so at lower noise, wider field)

Bill