When sourcing M12 lenses, you must prioritize the Optical Format (e.g., 1/2.3", 1/3") to ensure it matches or exceeds your sensor size to avoid vignetting. Key parameters include the Focal Length, which determines the Field of View (FOV), and the Aperture (F-number), which affects low-light performance. For high-resolution sensors, ensure the lens is rated for the correct Megapixel count (e.g., 5MP, 8MP, or 4K) to maintain image sharpness. Additionally, verify the TTL (Total Track Length) and Back Focal Length (BFL) to ensure mechanical compatibility with your camera housing and sensor mount.