mantona Per

Normally, a long focal length of 800 mm also has an overall length of nearly 80 cm to the sensor plane. To achieve a handy, universally applicable, and compact solution, this lens employs a clever trick. The light path is simply folded using two high-precision ground ring mirrors. This results in a compact design of only 131 mm in length compared to the mentioned nearly 80 cm. The minimum focusing distance is also reduced to 3.5 meters instead of at least 10 m with a lens-based system.

Focusing is done manually. The lens can be used with either automatic exposure or manual exposure settings, depending on the camera. In the folded light path, it is technically impossible to incorporate an iris diaphragm. If light reduction is necessary, this is simply achieved through 2x or 4x neutral density filters, which are screwed in front of the rear lens. There is an M30x0.5 thread available for this purpose.

Practical: The lens does not have a fixed infinity stop. Focusing is done in a swinging manner, allowing the sharp point to be confidently found from out of focus to sharp and back to out of focus at any distance.

T2 connection, operating tip: The T2 adapter is screwed onto the optics, and then the lens is locked in place. The side screws on the T2 adapter allow for adjustment after loosening, enabling the lens to be oriented with the index pointing upwards. Retightening the screws reliably secures the optics and adapter.

Advantages of a full-frame lens on a camera with an APS-C sensor: Save time in post-processing. Many lens errors such as distortion, edge softness, or vignetting occur at the outer areas of the image. When using a lens designed for full-frame on a camera with an APS-C sensor, these areas are not utilized. Thus, you achieve maximum quality.