Name of invention: zoom optical system, optical device and method for manufacturing variable magnification optical system
It consists of 6 or 7 groups of multiple lens groups, and the distance between lens groups changes when zooming. At least one image-side focusing lens group is arranged on the image side of the transverse focusing lens group, and moves along a trajectory different from that of the object-side focusing lens group when focusing; the object-side, the image-side focusing lens group and at least one focusing lens group have at least one lens with negative refractive power; the object-side focusing lens group consists of one lens group, and the object-side focusing lens group focuses the most. The variable magnification optical system has a fixed first lens.
I. Example 1 (22-70mm2.8)
Magnification 2.99
Focal length 22.7 50.0 67.9
F number 2.92 2.92 2.92
Angle of view 9 1. 10 45.68 33.64
Image height19.3221.6021.60
Full length188.45157.95157.95157.951.763.5438+09.
The back focal length is1.563.91921.5620.
Two. Example 6 (70-300mm F4.7-5.8)
Magnification 4.05
The focal length is 72. 1 100.0 292.0.
F number 4.74 4.8 1 5.88
Angle of view 34.32 24.20 8.28
Image height 21.6021.6021.60.
The total length is193.32211.66248.32.
Back focal length 38.32 39.78 62.52
Three. Example 7 (24-210mm F3.5-6.5)
The focal length is 24.7 70.0 2 10.0.
F number 3.47 5.3 1 6.52
Angle of view 85.94 32.52 1 1.08
Image height19.9021.6021.60
The total length is141.6173.636438+094.45.
Back focal length 33.236
Four. Example 9 (24-220mm f3.7-6.4)
Variable magnification 8.97
Focal length 24.8 70.0 222.0
F number 3.69 5.69 5.39 6.42
Angle of view 85.32 33.28 10.80
The image height is 20.3021.6021.6021.6021.60.
Total length152.38152.38168.67 204.50
Back focal length 13.25 40.90.90.90.550
It is worth noting that the wide-angle end of 22-70mm F2.8 is slightly wider than that of ordinary large ternary zoom, but the aberration diagram shows that there is still considerable distortion at the wide-angle end and the image height is not enough. Since there is no, it may be necessary to isolate the surrounding environment with distortion correction first.
70-300mm is a zoom range that Z mount does not have at present, so it is hoped to be commercialized. Because the F value of 70-300mm is F4.7-5.8, it looks like a popular telephoto zoom.
24-200mm F4-6.3 has been commercialized with high magnification zoom, but the lens in the example seems to be a little long at the telephoto end.