Correct, the MTF of a lens is meaningless unless the lens and sensor are aligned (aka focused) correctly. Contrast in the image is directly related to the squa

Correct, the MTF of a lens is meaningless unless the lens and sensor are aligned (aka focused) correctly. Contrast in the image is directly related to the square-wave geometrical MTF. Once you factor in focus/alignment error, it can be difficult to tell the difference between a "3MP" and "12MP" rated lens. We're talking about <10 micron accuracy. This is why companies like Apple use 6-axis active alignment machines to manufacture every camera module. The "Megapixel" rating of a lens is based on the nominal as-designed MTF and image sensor Format. There's a lot of manufacturer fudging that goes on with these ratings. And some in China literally print whatever they want on the side of a lens. I've seen the same lens with both "3MP" and "5MP" printed on it. Here are a few tips on how to focus a camera. Regardless, it'll be hard to get within 2-5 microns with a CS Mount 1"-32TPI thread. https://commonlands.com/blogs/technical/how-to-focus-a-camera https://commonlands.com/blogs/technical/how-to-focus-a-camer...