Nikon 180mm
Background
Both the Olympus 180/2.8 and the Nikon 180/2.8 were inspired by the Zeiss Sonnar 180/2.8, which was introduced for the 1936 Olympics in Germany. The name Sonnar was from the German word meaning sun. 'Sonne', the symbol of utmost brightness. The Sonnar lens type was invented by Dr. Ludwig Bertele at Zeiss in 1930. It is regarded as basically a combination of the Ernostar and Tessar lens types. Because of its large diameter and little glass-to-air surfaces it could provide the fastest lenses of that day when multi-coating was not yet avaliable. The lens had speed up to F/1.5 and well controlled veiling glare.
Sonnar in 180mm by Carl Zeiss
Hasselblad 500 series - Sonnar T* 4/180 CFE 5 elements in 4 groups
Contax/Yashica SLR - Sonnar T* 2.8/180 6 elements in 5 groups
The Nikon and Olympus lenses are, technically, Sonnar-like designs, with a positive group at the front, a negative group in the middle, and a weak positive element at the back. Nikon has taken the design and modified it substantially. The 180 lens has a very good correction of chromatic aberration. Today the lens is flawless with very well corrected aberrations including chromatic aberration and coma aberration. It is a high-performance lens that can be used even at the full open aperture.
History
Nikon introduced their first Nikkor lens at 180mm focal length, a 180mm F/2.5-32 Nikkor-H Preset in 1965. The lens requires a Nikon N->F adapter tube (BR-1) (61.5mm dia. by 62.3mm length, adds 58.5mm of extension) to shoot pictures.
Nikkor Auto 180 mm F/2.8 - optics design by Mr. MATSUI, Sei. This lens was his first work of interchangeable lenses for Nikon F.
1970 - released to the press only for the Sapporo Pre-Olympics
1971 - released to general public
1976 - used multi-layer coating
AI Nikkor 180 mm F/2.8
1977 - Nikkor Auto 180 mm F/2.8 was modified to AI Nikkor 180 mm f/2.8
1981 - AI Nikkor 180 mm F/2.8 ED was released - 5 elements in 5 groups
ED (Extra Low Dispersion Glass, a kind of rare glass)
AF Nikkor 180mm F/2.8
????? - 1st AF Nikkor 180mm F/2.8 ED was released
1995 - 2nd generation AF Nikkor 180mm F/2.8 IF-ED was released
2000 - 3rd generation AF Nikkor 180mm F/2.8 IF-ED D-type was released - 8 elements in 6 groups
????? - 4th generation AF-S Nikkor 180mm F/2.8 IF-ED D-type
IF (Internal Focusing)
Optics Design
The Sonnar lenses offer short barrel lengths due to telephoto lens type, and less saggital coma flare than Gaussian (Gauss-type) lenses. Telephoto type means a lens structure of convex front group and concave rear group. In the (1981) AI Nikkor 180 mm F/2.8 ED, the front group consists of three elements, convex-concave-convex and the rear group consists of two elements, concave-convex. ED glass is used for the top lens. It is capable of correcting chromatic aberration when combined with the second concave lens. Thus the lateral chromatic aberration which is always the problem with the telephoto lens is excellently corrected.
The feature of the telephoto type is to enable to make the overall length of the lens shorter than its focal length owing to the function of the rear-group concave lens. On the other hand, it has a drawback of generating a pincushion type distortion. In this lens, therefore, the structure of the rear group is made of two elements, concave and convex and this pincushion type distortion is cancelled out by the function of the last convex lens.
Further, this telephoto type has another feature of capability of correction aberrations by composing each lens with a thin lens, and it may be another feature of this lens that its size and weight is reduced in comparison to the former "Nikkor Auto". The effort paid by the designer of the lens barrel must have contributed very much to the down-sizing of the lens.
"Nikkor Auto" has a character of coloring the fringe of rear defocus in yellowish green and front defocus in reddish purple by influence of the residual chromatic aberration. The residual chromatic aberration influences not only to the focused plane but also to the front and rear defocused images.
On the other hand, the coloring of the fringe of defocus with "AI Nikkor ED" and "AI AF Nikkor ED" is very little and the defocused images appear smooth. With "AI Nikkor ED", the defocus linked from the focused plane to the front defocus appears hard, and with "AI AF Nikkor ED" the rear defocus just behind the focused plane appears hard. Images taken by these lenses are so alike that sometimes we cannot know the one from the other.
Specification
Nikon AF 180mm/F2.8 ED-IF D
| Groups / Elements: | 6 / 8 |
| Max / Min F/stop: | 2.8 / 22 |
| Closest Marked Focus Distance: | 1.5m (5 ft) |
| Max Reproduction Ratio: | 1/6.6 |
| Filter Attachment Size: | 72 mm |