Minolta W Rokkor 21mm lenses

Minolta W Rokkor 21mm

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

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.

Design and history

Minolta 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 2.1 cm 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 $2,120 in 2024). ^[5] By 1968, the successor Rokkor-QH f/4 retailed at a lower price, US$159.50(equivalent to $1,440 in 2024), with a dealer cost of US$95.70(equivalent to $870 in 2024). ^[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}

Minolta 21mm wide angle lenses for SR-mount

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

• List of Minolta SR-mount lenses

References

1. "Minolta SR Lens Index". minolta.eazypix.de. April 24, 2017. Retrieved 23 July 2024.
2. 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.
3. 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.
4. Sato, Haruo. "NIKKOR - The Thousand and One Nights No.1". Nikon Imaging. Retrieved 25 July 2024.
5. "Minolta Price Reference Guide" (PDF). Minolta Corp. August 31, 1964 – via Pacific Rim Camera, Reference Library.
6. "Price List: Minolta Photographic Equipment" (PDF). Minolta Corp. February 1968 – via Pacific Rim Camera, Reference Library.
7. "Minolta MC W.Rokkor-NL 21mm F/2.8". Lens-DB. Retrieved 24 July 2024.
8. 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.
9. Wolf, John C (1979). The Minolta Guide . Modern Camera Guide. Amphoto. ISBN   0-8174-2453-9 . Retrieved 24 July 2024.
10. "The Minolta SR System: Rokkor Interchangeable Lenses" (PDF). Minolta. 1967. Retrieved 23 July 2024– via Pacific Rim Camera, Reference Library.
11. Cooper, Joseph D. (1972). Minolta System Handbook (PDF). Amphoto – via Pacific Rim Camera, Reference Library.
12. "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

• 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.