Question 1: Is there evidence to question his ability or willingness to do an expert analysis?
Question 3: How good is Falch at analytical thought? What's his skill level in general?
Example: From YT video -
"Jellyfish" UAP analysis!
A muddled discussion of optics. Shows poor understanding of optics. Unclear thinking.
Typically, the first thing people think is it must be some kind of dead bug or bird poop on the window. These windows are exposed to a lot of debris and get filthy for sure.
However, the infrared optics see through this debris in the front window and it’s usually not an issue.
Allow me to explain. There is a wide range of focusing for the infrared optics.
Wrong word. Leaving aside the issue of what kind of optical system this really is... He means: The system is capable of adjusting the
focal length of the lens by moving lens elements inside the lens barrel.
Aside: This is a catadioptric optical system. A mixture of reflection and refraction. It uses a mirror and lenses. I don't think we should use the terms zoom lens or lens barrel. I know very little about the lenses at all. That's where my knowledge trails off. A man's got to know his limitations.
But there's some way to change the focal length and I would think it's done very much in the same way a zoom lens on a consumer camera does it.
I wonder if it could switch between a number of fixed focal length lenses? Like an old TV camera. Anyone know?
When changing magnification, the focus lens is used to focus the scene at a particular focal length.
By focus lens he probably means the element called the focusing lens. Yes, it adjusts focus. But why is this important? The discussion should be about focal length.
Leaving aside the issue of this being a catadioptric optical system, I think what he's trying to get at is the focal length. The long focal length and how it would affect focus.
Absolute basics
Focal length - How far away does the lens need to be from the film/sensor to form a focused image? It's why telephoto lenses are long and wide angle lenses are short. Affects field of view and magnification. The longer the focal length the higher the magnification and narrower the field of view.
Focus - A clear image, or fuzzy? The focusing lens moves a little bit back or forth inside the lens barrel to get best focus. Most of the focusing has already been done by having the lens at the right distance from the film/sensor.
Focal length and focus are not the same thing. Should not be confused.
Zooming, zoom lens - A zoom lens adjusts the focal length of the lens by physically moving lens elements inside the lens barrel. Changing the focal length does not include moving the focusing lens. (I can see the autofocus changing focus at the same time in a varifocal zoom lens. I wonder if that's what he means. But it wouldn't be relevant.) Focus and focal length should not be confused.
Important: Long lenses - long focal length lenses - telephoto lenses - can't focus at really close distances.
Infrared focal lengths are set far beyond the focal length of the front window.
Wut?
Infrared focal lengths - Probably means: The focal length of the lens. Could he be thinking about the wave length of IR light? Don't know. IR light does focus at a slightly different distance than visible light. But that's true of different colors of visible light. That's what chromatic aberration is all about. And why would it be important?
...
focal length of the front window - Do windows have a focal length? He's confused focal length with distance. He means the distance to the window.
Therefore, the infrared optics effectively see through any debris on the window.
infrared optics - Why even mention infrared? We already know it's an IR camera. But the relevant issue is focal length. Not fundamentally different in IR or visible light cameras. I get the idea that he's just slinging around the term because it sounds groovy.
What he's probably trying to say is: With the lens set to this long focal length anything on the window would be so out of focus it would be effectively invisible.
Which is true.