This is one of the second generation of bellows macro lenses for the Olympus OM system and was first produced around 1980. Like the other second-generation lenses, this one has an automatic diaphragm and a focusing helicoid to assist fine focusing. Olympus was the first manufacturer to introduce high-magnification macro lenses with automatic diaphragms.
The lens is designed for magnifications between 4.2× and 16×. It has the standard OM bayonet, and when used with the Telescopic Auto Tube 65–116, the available magnifications range from 6.8× to 9.5×. When used with the Auto Bellows, the available magnifications range from 5.3× to 13.6×; the Double Cable Release is needed to close the diaphragm. It can also be used with the Auto Extension Tubes.
The short working distance (18–20 mm) can make it difficult to light the subject, and so the front part of lens is tapered and stepped to help prevent the lens from blocking the light.
It has a 49mm filter mount set back from the front of the lens (so you cannot use it for filters) that is used for the special screw-in lens cap, and to which you can attach the T10 Ring Flash 1 and the mounting ring for the T-28 Macro Flash 1. The T8 Ring Flash 2 is not suitable, because of the short working distance of this lens.
This lens was introduced around 1980 and replaced the Zuiko Macro 20mm f/3.5 lens, which was slower, had a manual diaphragm, and had an RMS screw thread instead of the standard OM bayonet.
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Lowest magnification | ×5.3 | Subject area | ?×? mm | Working distance | 20 mm |
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Highest magnification | ×13.5 | Subject area | ?×? mm | Working distance | 18 mm |
Lowest magnification | ×6.3 | Subject area | ?×? mm | Working distance | 19 mm |
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Highest magnification | ×9.2 | Subject area | ?×? mm | Working distance | 18 mm |
A Lieberkühn Reflector and a Mirror Housing were made to fit this lens.
Self-adhesive labels were provided with the T Power Control 1 to stick onto a Calculator Panel to provide readings for manual flash with the T10 Ring Flash 1 and T28 Macro Single Flash 1.
The Macro Flash Shoe Ring screws into the 49 mm filter mount, and takes the heads of the T28 Macro Twin Flash 1 or the T28 Macro Single Flash 1.
See also: Close-up and Macro Photography – Bellows Macro Lenses
When the Zuiko Auto-Macro 20mm f/2 is mounted on the Auto Bellows attached to a digital body, the only ways to close down the iris diaphragm are to use the cable release socket or the stop down lever on the lens mount of the bellows. When it is mounted on the Telescopic Auto Tube, OM/EOS and OM/Four Thirds adapters change the automatic diaphragm to manual click stops.
The following tables are based on those in the instruction leaflet, with adjustments for different sensor sizes (smaller sensors reduce the field of view) and for any additional extension needed to allow the release lever on the rear of the Auto Bellows to clear an overhanging pentaprism or flash.
36×24 mm sensor, with 7 mm extension tube between bellows and OM/EOS adapter
Magnification | 6.0 | 7.0 | 8.0 | 9.0 | 10.0 | 11.0 | 12.0 | 13.0 |
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Subject area (mm) | 6.0 × 4.0 | 5.1 × 3.4 | 4.5 × 3.0 | 4 × 2.7 | 3.6 × 2.4 | 3.3 × 2.2 | 3.0 × 2.0 | 2.7 × 1.8 |
Bellows scale* (mm) | 76 | 96 | 116 | 136 | 156 | 176 | 196 | 216 |
Lens to subject distance (mm) | 20 | 19 | 19 | 19 | 18 | 18 | 18 | 18 |
22.2×14.8 mm APS-C sensor, with 14 mm extension tube between bellows and OM/EOS adapter
Magnification | 6.0 | 7.0 | 8.0 | 9.0 | 10.0 | 11.0 | 12.0 | 13.0 |
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Subject area (mm) | 3.7 × 2.5 | 3.2 × 2.1 | 2.8 × 1.85 | 2.5 × 1.6 | 2.2 × 1.5 | 2.0 × 1.3 | 1.85 × 1.2 | 1.7 × 1.1 |
Bellows scale* (mm) | 69 | 89 | 109 | 129 | 149 | 169 | 189 | 209 |
Lens to subject distance (mm) | 20 | 19 | 19 | 19 | 18 | 18 | 18 | 18 |
17.3×13.0 mm Four-Thirds sensor, with no extension tube between bellows and OM/Four Thirds adapter
Magnification | 6.0 | 7.0 | 8.0 | 9.0 | 10.0 | 11.0 | 12.0 | 13.0 |
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Subject area (mm) | 2.9 × 2.2 | 2.5 × 1.9 | 2.2 × 1.6 | 1.9 × 1.4 | 1.7 × 1.3 | 1.6 × 1.2 | 1.4 × 1.1 | 1.3 × 1.0 |
Bellows scale* (mm) | 83 | 103 | 123 | 143 | 163 | 183 | 203 | 223 |
Lens to subject distance (mm) | 20 | 19 | 19 | 19 | 18 | 18 | 18 | 18 |
17.3×13.0 mm Four-Thirds sensor, with 7 mm extension tube between bellows and OM/Four Thirds adapter
Magnification | 6.0 | 7.0 | 8.0 | 9.0 | 10.0 | 11.0 | 12.0 | 13.0 |
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Subject area (mm) | 2.9 × 2.2 | 2.5 × 1.9 | 2.2 × 1.6 | 1.9 × 1.4 | 1.7 × 1.3 | 1.6 × 1.2 | 1.4 × 1.1 | 1.3 × 1.0 |
Bellows scale* (mm) | 76 | 96 | 116 | 136 | 156 | 176 | 196 | 216 |
Lens to subject distance (mm) | 20 | 19 | 19 | 19 | 18 | 18 | 18 | 18 |
* The bellows scale should be read at the rear of the body mount, with the lens mount positioned at the front end of the rail.
(Cameras such as Canon EOS 40D)
Magnification | 7.0 | 8.0 | 9.0 | 10.0 |
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Subject area (mm) | 3.2 × 2.1 | 2.8 × 1.85 | 2.5 × 1.6 | 2.2 × 1.5 |
Tube length (mm) | 70 | 90 | 110 | 116 + helicoid |
Lens to subject distance (mm) | 19 | 19 | 19 | 18 |
(Cameras such as Olympus E-series and Micro Four Thirds)
Magnification | 7.0 | 8.0 | 9.0 | 10.0 |
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Subject area (mm) | 2.5 × 1.9 | 2.2 × 1.6 | 1.9 × 1.4 | 1.7 × 1.3 |
Tube length (mm) | 70 | 90 | 110 | 116 + helicoid |
Lens to subject distance (mm) | 19 | 19 | 19 | 18 |
Reproduced with permission from the copyright owner, Olympus Optical Co., Ltd
ZUIKO AUTO-MACRO 20mm 1:2
These macro lenses feature the world’s first automatic diaphragm operation for high magnification works in conjunction with the OM System macrophoto units.
• Combinations
Varimagni Finder or Dioptric Correction Lens 1 + Eyecup 1 |
OM-2N or OM-1N |
Focusing Screen 1-4 or Focusing Screen 1-11 or Focusing Screen 1-12 |
Auto Extension Tube 14 or Auto Extension Tube 25 or Telescopic Auto Extension Tube 65~116 or Auto Bellows or Macrophotographic Equipment PMT-35 |
Macro 20mm F2 |
•Specifications
Focal length | 20 mm |
Angle of view | 9° (at high magnification) |
Optical construction | 6 elements in 4 groups,multi-coated |
Diaphragm operation | Automatic |
F/stop range | 2 ~ 16 |
Minimum field size | Max. 5.7 × 8.6mm (4.2×) Min. 1.8 × 2.6mm (13.6×) |
Focusing | With Auto Extension Tube 15, 25, 65 ~ 116 or Auto Bellows |
Fine-focusing | With direct helicoid built into lens |
Length | 46mm (1.8 in.) |
Maximum diam. | 60mm (2.4 in.) |
Weight | 170g (6.0 oz.) |
• Care and storage
• With Auto Bellows
Subject Area Covered (mm) | 6.5 × 4.4 | 6 × 4 | 5.5 × 3.7 | 5.1 × 3.4 | 4.5 × 3.0 | 4 × 2.7 | 3.6 × 2.4 | 3.3 × 2.2 | 3.0 × 2.0 | 2.7 × 1.8 | ||
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Magnification | 5.5 | 6.0 | 6.5 | 7.0 | 8.0 | 9.0 | 10.0 | 11.0 | 12.0 | 13.0 | ||
Scale (mm) | 68 | 73 | 83 | 93 | 103 | 123 | 143 | 163 | 183 | 203 | 223 | 231 |
Distance from lens to subject (cm) | 2.0 | 2.0 | 2.0 | 1.9 | 1.9 | 1.9 | 1.9 | 1.8 | 1.8 | 1.8 | 1.8 | 1.8 |
• With Telescopic Auto Extension Tube 65 ~ 116
Subject Area Covered (mm) | 5.1 × 3.4 | 4.5 × 3.0 | 4 × 2.7 | 3.6 × 2.4 | |
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Magnification | 7.0 | 8.0 | 9.0 | 10.0 | |
Tube length (mm) | 65 | 70 | 90 | 110 | 116 + helicoid |
Distance from lens to subject (cm) | 1.9 | 1.9 | 1.9 | 1.8 |
• With Auto Extension Tube 14
Subject Area Covered (mm) | 9 × 6 | 8 × 5.3 |
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Magnification | 4.0 | 4.5 |
Tube length (mm) | 14 | 14 + helicoid |
Distance from lens to subject (cm) | 2.1 | 2.1 |
• With Auto Extension Tube 25
Subject Area Covered (mm) | 8 × 5.3 | 7.2 × 4.8 |
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Magnification | 4.5 | 5 |
Tube length (mm) | 25 | 25 + helicoid |
Distance from lens to subject (cm) | 2.0 | 2.0 |
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Created 18th May 2001 — Updated 16th April 2023
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