Anyone need an infrared polarizer?

[Andy Perrin]

I have a very similar one, it works fine. 780-1250nm.

 

https://www.ebay.com...=item548c172552

[Fandyus]

If I had the funds, I'd for sure buy it.

[OlDoinyo]

20mm diameter won't cover many optics--except perhaps Micro 4/3.

[Andy Perrin]

Eh, you put it in a step ring and use a lens with a long focal length. I found 80mm and up is okay. It covers the whole sensor on my 35mm A7S just fine as long as the light is restricted to relatively small angles.

 

I mean, pinhole photos work too, and the pinhole is much smaller than 20mm…the size of the filter itself is not the only thing that determines if you can cover the sensor.

[Stefano]

How close you can mount it on the lens also matters. I have been experimenting with 25 mm filters and I found a way to mount them on my 35 mm Soligor without vignetting (with an APS-C sensor).

[dabateman]

It depends on where you place the filter.

Many of the lenses we use which are good in UV or IR have very small lens elements.

If the filter is very close to the front element or rear element, it should be fine. Especially if the element is less than 20 mm. But if the filter us close to the sensor, than I see a problem. Even for m43rds sensors.