The W Rokkor 21mm lenses are a series of three prime wide angle lenses produced by Minolta for Minolta SR-mount single lens reflex cameras. The first 21mm lens released was the W Rokkor-PI 21mm f/4.5 (1962), which featured a symmetrical design similar to the contemporary Zeiss Biogon. This was succeeded by the W Rokkor-QH 21mm f/4 (1963), with slightly improved speed and similar symmetric construction. The third and final 21mm lens was the MC W Rokkor-NL 21mm f/2.8 (1971), which featured a retrofocus design that did not require the reflex mirror to be locked up, allowing use of the built-in viewfinder.
.jpg) First (1962) version, W Rokkor-PI | |
| Maker | Minolta |
|---|---|
| Technical data | |
| Focal length | 21mm |
| Features | |
| Ultrasonic motor |  No |
| Macro capable | No |
| Physical | |
| Filter diameter | Integrated |
| Accessories | |
| Lens hood | Integrated Flower |
| Angle of view | |
| Diagonal | 92° |
| History | |
| Introduction | 1962 |
| Discontinuation | 1977 |
| Successor | W Rokkor 20mm f/2.8 |
Design and history
editMinolta updated the design several times during the course of production; the first two versions were symmetric designs which required the reflex mirror to be locked up, while the third version was a retrofocus design, followed by a cosmetic update in 1973.[1]
When the Rokkor-PI f/4.5 was introduced, it was advertised as "a product of much painstaking work and research by the company's technical staff", which Erhard Bertele called "a mockery" in retrospect, declaring it "[an imitation of the Biogon] with seemingly insignificant small changes to the original Bertele design".[2] The similarities in lens design between the Biogon and the Rokkor-PI f/4.5 have led to speculation the latter was discontinued in favor of the Rokkor-QH f/4 in response,[3] as the -QH shares a similar 8-element, 4-group design as the Nikkor-O 2.1cm f/4 (1959).[4] In 1964, the suggested retail price of the Rokkor-PI f/4.5, with accessory viewfinder and leather case, was US$209.50 (equivalent to $2,060 in 2023).[5] By 1968, the successor Rokkor-QH f/4 retailed at a lower price, US$159.50 (equivalent to $1,400 in 2023), with a dealer cost of US$95.70 (equivalent to $840 in 2023).[6]
The Rokkor-NL f/2.8, introduced in 1971, has three floating elements to compensate for focusing aberrations at close range.[7][8] It was replaced by the MD Rokkor 20mm f/2.8 lens (1977), which was more compact and lighter.[9]: 74
Model Spec
|
W Rokkor-PI 21mm f/4.5 | W Rokkor-QH 21mm f/4.0[10] | MC W Rokkor NL 21mm f/2.8[11]: IV-47 | MC W Rokkor(-X) NL 21mm f/2.8[12] | |
|---|---|---|---|---|---|
| Year | 1962 | 1963 | 1971 | 1973 | |
| Construction | Elements | 9 | 8 | 12 | |
| Groups | 5 | 4 | 9 | ||
| Aperture | f/4.5–16 | f/4.0–16 | f/2.8–16 | ||
| Min. focus | 0.9 m (35.4 in) | 0.25 m (9.8 in) | |||
| Metering features | Meter coupling (MC) tab |  No |
No
|
 Yes |
Yes
|
| Minimum diaphragm (MD) tab | No |
No
|
No |
No
| |
| Aperture lock | No |
No
|
No |
No
| |
| Dimensions | Diam. | 60 mm (2.4 in) | 75 mm (3.0 in) | ||
| Length | 20 mm (0.8 in) | 67 mm (2.6 in) | |||
| Weight | 170 g (6.0 oz) | 166 g (5.9 oz) | 510 g (18 oz) | ||
| Filter (mm) | 55 | 72 | |||
See also
editReferences
edit- ^ "Minolta SR Lens Index". minolta.eazypix.de. April 24, 2017. Retrieved 23 July 2024.
- ^ Bertele, Erhard (2019). Ludwig J. Bertele: A Pioneer of Geometric Optics. vdf Hochschulverlag AG an der ETH Zürich. p. 88. ISBN 978-3-7281-3956-6. Retrieved 24 July 2024.
- ^ keikato (September 14, 2022). "水曜日。京大のAL-2000が安く出ていた。W.ROKKOR-PI 21mm f4.5について。AiS 24mm f2 初期シリアルを発見して買った" [Wednesday. Kyoto University's AL-2000 was on sale for a low price. About the W.ROKKOR-PI 21mm f4.5. I found a low serial number of the AiS 24mm f2 and bought it.]. 今日を生きた証 (in Japanese). Retrieved 25 July 2024.
- ^ Sato, Haruo. "NIKKOR - The Thousand and One Nights No.1". Nikon Imaging. Retrieved 25 July 2024.
- ^ "Minolta Price Reference Guide" (PDF). Minolta Corp. August 31, 1964 – via Pacific Rim Camera, Reference Library.
- ^ "Price List: Minolta Photographic Equipment" (PDF). Minolta Corp. February 1968 – via Pacific Rim Camera, Reference Library.
- ^ "Minolta MC W.Rokkor-NL 21mm F/2.8". Lens-DB. Retrieved 24 July 2024.
- ^ Schwalberg, Bob (January 1961). "photokina '70: lenses" (PDF). Popular Photography. p. 84. Retrieved 24 July 2024.
The 21-mm MC W-Rokkor-NL f/2.8 has three floating elements in its front section that move about 2-mm when the lens is focused between infinity and 10 in. Probably the fastest lens of its focal length to date, this 21-mm f/2.8 has 12 elements, half of which are stated to be special rare-earth types.
- ^ Wolf, John C (1979). The Minolta Guide. Modern Camera Guide. Amphoto. ISBN 0-8174-2453-9. Retrieved 24 July 2024.
- ^ "The Minolta SR System: Rokkor Interchangeable Lenses" (PDF). Minolta. 1967. Retrieved 23 July 2024 – via Pacific Rim Camera, Reference Library.
- ^ Cooper, Joseph D. (1972). Minolta System Handbook (PDF). Amphoto – via Pacific Rim Camera, Reference Library.
- ^ "A guide to the Minolta SLR system of creative photography (SLR SYSX 603-H1)" (PDF). Minolta Camera Co., Ltd. March 1976 – via Vintage Camera Digest.
External links
edit- Lohmann, Dennis (2014). "Minolta SR Lens Test: W.ROKKOR-PI 21mm 1:4.5". minolta.eazypix.de.
- Gandy, Stephen (November 25, 2003). "Minolta 21/4 SRT Lens for Leica M". cameraquest.com.
- Bierner, Matt (June 26, 2016). "The Quest for the World's Ugliest Photo". MattBierner.com.
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