Zuiko

Zuiko (Japanese: ズイコー or 瑞光) is a brand of optical lenses[1] made by Olympus Corporation that was used up to and into the Four Thirds system era.

The engraving dropped the number of elements with the advent of multicoating, which occurred during the production of OM system lenses.

Ace, Pen-F, FTL, and early OM system lenses carry the letter prefix denoting the number of optical elements.

[9][10] It was a viewfinder camera using a 24×32mm frame size fitted with a fixed (non-interchangeable) 'Zuiko Coated' 40mm f/3.5 lens; that same lens was also used on the subsequent 35 III (released in 1949 and changed the frame size to the standard 24×36mm), IV (IV in 1949, IVa in 1953, and IVb in 1954), and V (Va and Vb, both in 1955).

[7]: 13  [11][12] A version of the Wide using the same lens was produced in 1957 with an integral uncoupled meter, branded the Wide-E.[7]: 14–15  [10] The Wide-E was sold in the United States as the Sears Tower 54.

[21] The Auto Eye of 1960 succeeded the older electro-set models and added full shutter-priority autoexposure using a non-interchangeable version of the D.Zuiko 45mm f/2.8 from the Ace.

[7]: 31–32 Also in 1962, Olympus released the S Electro Set (engraved with 'Olympus-S' on the top plate), which used the G.Zuiko 42mm f/1.8 lens from the original Auto.

[7]: 33  An updated version designated SC was released in 1963; it retained the 'Olympus-S' top plate engraving using the same lens but switched the meter technology from selenium cell to cadmium sulfide (CdS).

[7]: 34–35  The successor of the Olympus-S twins was the first of the two-letter 35 xx models, released in 1965; the Olympus 35 LE used a slightly faster G.Zuiko 42mm f/1.7 lens with similar double Gauss optical construction and prominently advertised the use of six transistors.

It was a scale/zone-focused camera based on the Pen EES[25] which featured a D.Zuiko 40mm f/2.8 Tessar-type lens, two automatically selected shutter speeds (1⁄40, which doubled as the manual flash sync speed, and 1⁄200) for aperture-priority autoexposure, or programmed autoexposure driven by the selenium cell meter.

[7]: 53  [22] In 1974, Olympus released the 35 ED, last of the 'economy' line, equipped with a slightly wider D.Zuiko 38mm f/2.8 lens, rangefinder focusing, and programmed autoexposure only.

[7]: 54  [15][26] In 1970, Olympus marketed the 35 RC as a mid-range compromise; although it was approximately the same size as the 35 EC using the same E.Zuiko 42mm f/2.8 lens, the 35 RC added more advanced features from the 35 SP including true rangefinder focusing and the option of either shutter-priority autoexposure or manual exposure control.

[7]: 48–49  [23][26] The 35 DC ("Deluxe Compact") of 1971 also offered rangefinder focusing of a faster F.Zuiko 40mm f/1.7 lens, but was limited to programmed autoexposure only.

[7]: 50–51  [16][27] Finally, in 1975, Olympus released the 35 RD, combining the faster F.Zuiko 40mm f/1.7 lens from the 35 DC with the shutter-priority autoexposure or manual exposure controls of the older 35 RC.

[7]: 55–56 Yoshihisa Maitani, who had joined Olympus in 1956, is credited as the father of the Pen half-frame camera line.

[7]: 75–76  The two Pen-EE and EE S models gained 'EL' (Easy Load) variants in 1966 with a new six-slot film take-up spool.

[7]: 68 Also in 1962, the more advanced Pen-D was released, featuring a significantly faster F.Zuiko 32mm f/1.9 lens and an uncoupled selenium meter, whose readings were manually transferred to set exposure.

[7]: 87 The Olympus Quickmatic EEM incorporated features from the Pen EM (motor-driven film advance) and Pen-EE (program autoexposure according to the selenium cell "electric eye") in a viewfinder camera using another Tessar variant, the D.Zuiko 36mm f/2.8.

[38][39] The 35 xx models were replaced in 1979 by the Olympus XA, which was comparable to the 35 RC and RD in function, but markedly smaller with a sliding lens cover.

")[45] and still seeing unsatisfactory results from the team, Maitani began to design a new compact camera himself, prioritizing size so that it could be carried everywhere.

[49] The four successive numbered models in the XA series (XA1, XA2, XA3, XA4) largely used the same black metal capless/capsule body design with slower lenses that were zone focused, with the exception of the fixed-focus XA1, which was similar in concept to the Pen EES and Trip 35.

The line of Zuiko Digital-branded lenses marketed for Four Thirds system digital single-lens reflex cameras consists of the following sets from least to most expensive, separated by marketing grade:[67][68] HG and SHG lenses include a focus distance scale.

All Zuiko Digital lenses are "true zooms" which do not shift the focus point through the focal length range.