Knowledge bombs from the pros ACTinBlack – Know your Nods!
Wide Field of View has been a subject for a while with manufacturers making 47.5°, 50°, 51°, 60° and even 80°FOV optics for various systems. The degree of distortion, fish-eye and resolution loss compared to regular 40°FOV optics varies between the different optics.
Going beyond 50°FOV is sadly pushing the capabilities of current tubes, but even more so the photocathode diameter of 18mm. Physics are out to get you and they remain unforgiving in the fact that you can’t focus endless amount of information/photons through the given size of a photocathode. So pushing it beyond 50°FOV is going to cost performance of the overall system.
Will you always notice that? Probably not, but if system resolution drops, long range observation becomes an issue. If aperture drops, low light becomes an issue. if distortion or other unwanted optical effects start degrading the image quality, seeing through the optics becomes distracting.
So what advantage do WFOV have? In the first picture you see a cut image of 50° vs 40°. Items in the picture are at same size, but you see almost 40% more image in 50° optics.
In actual use this means a user has to move their head significantly less while scanning and noticeably improved situational awareness.