Name of invention: zoom optical system and optical equipment using the same.
The problem to be solved is to provide a zoom optical system in which aberration fluctuation during zooming and focusing can be effectively suppressed.
Previously, zoom optical systems suitable for cameras, electronic cameras, video cameras, and the like have been proposed. However, the optical performance of the traditional zoom optical system is insufficient.
According to each embodiment, by reducing the size and weight of the focusing lens group, quietness during high-speed AF and AF is realized without increasing the size of the lens barrel, and in addition, a zoom optical system that satisfactorily suppresses aberration fluctuation during zooming and aberration fluctuation during focusing from an infinite object to a near object can be realized from a wide-angle end state to a telephoto end state.
Example1(70-300mm F/4.5-5.8)
Zoom ratio 4.05
The focal length is 72. 1mm, 99.9mm and 292.0 mm.
F numbers are 4.57, 4.79 and 5.88.
Half angle of view 33.24 23.82 8.24
The maximum image heights are 21.60mm, 21.60mm and 21.60mm. ..
The total length is 19 1.32mm, 204. 14mm, 24 1. 16mm.
The back focal length is 38.52mm, 42.04mm and 60.52mm,
The zoom optical system ZL of this embodiment has four to five lens groups, namely L 1 1-L 13, L2 1-L25, L3 1-L36, L4 1-L42 and L5/kloc. By changing the distance between lens groups during zooming, good aberration correction during zooming can be achieved. In addition, by arranging the focusing lens group in the subsequent lens group GR, the focusing lens group can be made smaller and lighter.
This group of patents are all six different schemes designed around the focal length of 70-300, of which three are complete schemes and three are simplified schemes. From the perspective of the space of the back focus, they are all lenses that are suitable for mirrorless cameras. However, the 38.52mm back focus at the wide-angle end is relatively short for SLR cameras, so it can't be used for SLR cameras, but only for mirrorless cameras. 70-300mm small aperture zoom lens, easy to carry around.
The telephoto end of the patented lens is F5.8, while the aperture of the traditional telephoto end is 5.6. If it is to be commercialized, will it be an S series lens or a non-S series lens? After all, there are 18 lens and 17 lens in the six design schemes, which represents the different complexity of lens correction. Perhaps this should be tracked and determined according to Nikon's manufacturing cost and market demand. However, judging from the popularity of Nikon 800/6.3 lens, small aperture, light weight and low price are the key factors favored by the market.