Zeiss 18mm F2.8 Batis Distagon T* - Sony E

18mm F2.8 Batis Distagon T* - Sony E 

Originally developed for SLR cameras requiring a long back focal distance for short focal lengths because of the mirror box (the distance between the back lens element and the film plane must be considerably longer than the focal length), the Distagon lenses (retrofocus design) are also ideal for mirrorless system cameras thanks to their optimized ray path.
Even with longer focal lengths, the high-performance Distagon optical design enables consistently good correction all the way to the corners of the image and very low field curvature.
Specifications:
Focal length 18 mm
Aperture range f/2.8 – f/22
Camera mount Sony E-Mount*
Format compatibility Full Frame
Focusing range 0,25 m (9.8") – 8
Free working distance 0,17 m (6.7") – 8
Angular field** (diag. | horiz. | vert.) 99° / 90° / 67°
Diameter of image field 43 mm (1.69")
Coverage at close range (MOD)** 227 x 340 mm (8.9 x 13.4")
Image ratio at minimum object distance 1 : 9.5
Lens elements | groups 11 / 10
Flange focal distance 18 mm (0.71")
Entrance pupil position (front of image plane) 73 mm (2.9")
Features Autofocus +
Image Stabilization –
Physical Filter thread M77 x 0.75
Rotation angle of focusing ring Focusing not mechanically coupled
Diameter max. 100 mm (3.9")
Diameter of focusing ring 78 mm (3.1") 
Length (with lens caps) 95 mm (3.7")
Length (without lens caps) 80 mm (3.1")
Weight 330 g (0.74 lbs)