Why not use this kind of camera for paranormal? (And some scientific insight)

Intro
Have you ever heard about the cameras that are being used for paranormal investigations? Most of the time there's a ghost show on TV, the crew that's filming is using Infrared cameras or thermal cameras at night. Why don't they film during the day?
And if I were someone who was trying to capture paranormal activity, I would try to use a camera such as this one: https://www.youtube.com/watch?v=FyH-b_LDlSY. Now, you might argue that you could just use a full spectrum camera, which seems is what people sometimes do. I see a problem with full spectrum, though. Yes, even though a full spectrum camera can usually see more light than an Infrared, Visible, or especially UV camera, the thing is that a full spectrum camera focuses on a relatively broad spectrum of light. That can be a problem as well as a benefit. The problem comes in when you want to get sharp pictures. As camera's pixels increase, we need sharper lenses to get a clear picture. If you focus on a narrow band of light, you can obtain sharper images. When we use a camera that sees Ultraviolet only, we get rid of the Infrared and Visible spectrum, which would otherwise drown out anything that is visible in Ultraviolet, and diffraction can take place unless a high quality lens is used, which can be pricy. Let's compare this problem to an analogy in which you are studying in college! If you focus on too much at once, then you are probably not going to be as successful as if you were to focus on something specific.
And how about focusing on various bands of the UV spectrum to map bands that are, say, 1nm wide, into the RGB spectrum? This logic could even apply to IR or visible photography. Also, even though we only see Red, Green, and Blue, we can divide these colors up into ever smaller spectrums. This is a reason why we can create so many colors. Just like there is not just North, South, East and West; there is also NNE, SSW, etc. But we only see down to a certain wavelength. That's why I think we should create a camera that can focus on a band of light that is so narrow that it goes beyond our spectral resolution; let's create another analogy, to explain this. Let's say that the same logic applies to distance; let's think about red, green, and blue as the 1 inch, 2 inch, and 3 inch mark on a ruler. Because our color receptors only see in these three what I would call "dimensions" (figuratively speaking), we are limited. After all, there are also halves of an inch,  kind of like creating an extra color. However, there is a single, smallest unit of distance which we can see. The smallest unit that we can see is down to about 0.01 degrees. So we can create a telescope to zoom in on stars that are apparently separated by arc seconds, not degrees. Or we can create a microscope to see things much smaller than the width of a human hair, which would probably be too small to see. See where I'm going with this? We can create a camera that can resolve bands of light too small for us to distinguish with our own vision. Because, as I've already mentioned, light is essentially composed of an unknown, possible indeterminate, amount of wavelengths (not colors, as colors are officially a product of the brain's processing). So, I truly hope that this makes sense and if it doesn't then please reread this as it might take some time for some people to "decode".