CCTV lenses are usually C-mount, often have very short focal lengths, and are also very cheap compared to a lens from a DSLR or mirrorless camera. You do still have to consider the crop factor, but it isn't as much of an issue because CCTV lenses usually have shorter focal lengths. Most, but not all, CCTV lenses have focusing rings, so keep an eye out for that.

They are really great options, and probably have the best price to performance ratio. However, since they are designed to be used with CCTV cameras which tend to have pretty low-resolution sensors, the glass does not need to be as high-quality as the glass you'd find in a much more expensive lens from an interchangeable-lens camera.

That being said, there are so many other things that affect your image quality that in my personal opinion, it makes the most sense to use a CCTV lens until you actually feel limited by it, and then look into upgrading.

They're probably the best option for most people, but if you're really looking for the absolute best image quality possible, you may want to consider another option. Adafruit carries the following lenses, which are pretty solid and can get great image quality.