Marshall Electronics V-4350-2.5 50mm F2.5 M12 Miniature Glass Lens

The V-4350-2.5 is the longest lens in Marshall's 4300 series, a 50mm F2.5 on the same M12 x 0.5 thread the rest of the line uses. Five degrees across the frame on a 1/3 inch sensor is genuine telephoto reach for a miniature camera: a licence plate at the gate, a control panel across a room, an inspection target held still on a line.

It is a physically larger lens than its short siblings, 48.8mm long and 27.1 g, with four elements and a 33.9mm back focal length, so check clearance behind the sensor before specifying it. Minimum focus is 40 cm and it covers 1/3 inch and 1/2 inch formats.