ZEISS Biogon T 2.8/21 M42-I
商品類別：ZEISS 機器視覺工業鏡頭
ZEISS ZM-I Lenses - These lenses are developed for industrial cameras
Focal Length : 21mm
Max. Aperture : 2.8
Min. Free Working Distance : 420mm
Filter Thread : M46 × 0.75
Camera Mount : M42 × 1
Features
● f/2.8 aperture
● Precise manual focusing
● Robust full-metal construction
● Fixation for focus and aperture
● Outstanding image quality
● Compact and lightweight
● For industrial cameras up to sensor sizes of 24×36 mm or 43mm line sensors
Optical data
| Focal length | 21mm |
| Aperture range | f/2.8 – f/22 (1/ 3 stop intervals) |
| Number of elements / groups | 9 / 7 |
| Focusing range | 0.5m- infinity |
| Min. free working distance | 420mm (1.38 ft.) |
| Angular field* (diag. / horiz. / vert.) | 90 / 80 / 58° |
| Max. diameter of image field | 43mm (1.7") |
| Flange focal distance | M-42I : 26.8mm |
| Coverage at close range* | 47 × 71cm |
| Image ratio at close range | 1:21 |
| Filter-thread | M46 × 0.75 |
| Weight | 300g (0.66 lbs) |
| Length | 64mm |
| Camera mount | M42-I |
* referring to 24×36mm sensor format
Relative Illuminance*
Relative Distortion*
* data for infinite focus setting
MTF Charts*
* data for infinite focus setting