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Mamiya Sekor A 200 mm f/2.8 APO Lens

Photos and text © 1997 - 2013 Carlo Kopp; Photographs produced using a  Mamiya M645/1000S, 645AFD or Nikon D90, film scans Noritsu QSS 1300 PPI / 6 MP; almost all images produced in acceptance test or validation shoots.



Sekor A 200 mm f/2.8 APO Lens Examples



The Sekor A 200 mm f/2.8 APO (apochromatic) is part of the final generation of Mamiya manual focus lenses, and was not replaced in the subsequent AF series of lenses for the 645AFD. This lens is considered by many photographers, including this author, to be one of the outstanding optical designs produced by Mamiya. The example I acquired used, in the United States some years ago, was later readjusted by Mamiya in Japan, and delivers centre sharpness of 120 lp/mm which is exceptional by any measure.

For comparison, the centre sharpness of this apochromat is essentially more than 50% greater than the sharpness of typical and very good Sekor C series primes, while the lens also delivers exceptionally high contrast. Peak sharpness on this example is observed at f/5.6 and f/8.0.

The
Sekor A 200 mm f/2.8 APO performs equally well on the 645AFD, as it does on Nikon DSLRs.



Sekor A 200 mm f/2.8 APO Lens mounted on a Nikon D90 with a Fotodiox Pro adaptor, April, 2011 (HS10 10 MP).



Sekor A 200 mm f/2.8 APO Lens mounted on a Mamiya 645AFD, October, 2010 (HS10 10 MP).

Sekor A 200 mm f/2.8 APO Lens / Legacy2Digital Adapter



A 2011 acquisition was a Fotodiox Mamiya/Nikon adaptor modified by Legacy2Digital in the US with a digital emulator chip, which presents the lens to the camera body as a Nikon device. It is preprogrammed to represent the 200 mm f/2.8 APO with the proper focal length and maximum aperture. This enables the full range of automated features in a Nikon body, in this instance a D90.

Sekor A 200 mm f/2.8 APO Lens Test Targets (D90 DX/APS-C)




Test target using the same 200 mm f/2.8  APO manual focus lens at f/5.6 mounted on a Nikon D90 at 220 ISO and 1/4000. Uncorrected 12.3 Megapixel original - the DX sensor crop factor produces similar effect to a single 2XN teleconverter [Click image to view full size].



Test target (above, below) using the same 200 mm f/2.8  APO manual focus lens with single Kenko M45 2XN teleconverter at f/4.0 mounted on a Nikon D90 at 800 ISO and 1/2000. Uncorrected  12.3 Megapixel originals. This configuration produces the same angular coverage as the lens with two stacked 2XN teleconverters. Handheld shot as the moment produced by the lens and teleconverter was judged to be great enough to damage the tripod clamp [Click image to view full size].



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Test target using the same 200 mm f/2.8  APO manual focus lens with two stacked 2XN teleconverters at f/4.0 mounted on a Nikon D90 at 800 ISO and 1/1600. Uncorrected  12.3 Megapixel original. This configuration produces the same angular coverage as the lens with three stacked 2XN teleconverters. Handheld shot as the moment produced by the lens and pair of teleconverters was judged to be great enough to damage the tripod clamp [Click image to view full size].

Sekor A 200 mm f/2.8 APO Lens Test Shots (D800 FX/FF)

Click to enlarge image

Palm tree test target using the 200 mm f/2.8  APO manual focus lens at f/5.6 mounted on a Nikon D800 at 2000 ISO and 1/5000, using the Legacy2Digital modified adaptor. 36 Megapixel original cropped and adjusted for exposure using Aperture 3, reduced to 1024 pixels width, and below, 1:1 1024^2 pixel crop [Click image to view 1:1 resolution].

Click to enlarge image

Click to enlarge image

Lemon tree test target using the 200 mm f/2.8  APO manual focus lens at f/5.6 mounted on a Nikon D800 at 2000 ISO and 1/5000, using the Legacy2Digital modified adaptor. 36 Megapixel original cropped and adjusted for exposure using Aperture 3, reduced to 1024 pixels width, and below, 1:1 1024^2 pixel crop [Click image to view 1:1 resolution].

Click to enlarge image

Click to enlarge image

Ceramic pig test target using the 200 mm f/2.8  APO manual focus lens at f/5.6 mounted on a Nikon D800 at 560 ISO and 1/8000, using the Legacy2Digital modified adaptor. 36 Megapixel original cropped and adjusted for exposure using Aperture 3, reduced to 1024 pixels width, and below, 1:1 1024^2 pixel crop [Click image to view 1:1 resolution].

Click to enlarge image

Click to enlarge image

Sage blossom test target using the 200 mm f/2.8  APO manual focus lens at f/5.6 mounted on a Nikon D800 at 1250 ISO and 1/5000, using the Legacy2Digital modified adaptor. 36 Megapixel original cropped and adjusted for exposure using Aperture 3, reduced to 1024 pixels width, and below, 1:1 1024^2 pixel crop [Click image to view 1:1 resolution].

Click to enlarge image

Click to enlarge image

Garden weed test target using the 200 mm f/2.8  APO manual focus lens at f/5.6 mounted on a Nikon D800 at 1250 ISO and 1/2000, using the Legacy2Digital modified adaptor. 36 Megapixel original cropped and adjusted for exposure using Aperture 3, reduced to 1024 pixels width, and below, 1:1 1024^2 pixel crop [Click image to view 1:1 resolution].

Click to enlarge image

Click to enlarge image

Click to enlarge image

Click to enlarge image

Domestic cat test target using the 200 mm f/2.8  APO manual focus lens at f/5.6 mounted on a Nikon D800 at 1250 ISO and 1/8000, using the Legacy2Digital modified adaptor. 36 Megapixel original cropped and adjusted for exposure using Aperture 3, reduced to 1024 pixels width, and below, 1:1 1024^2 pixel crop [Click image to view 1:1 resolution].

Click to enlarge image

Sekor A 200 mm f/2.8 APO Lens Test Shots (D90 DX/APS-C)



Feline test target using the same 200 mm f/2.8  APO manual focus lens at f/5.6 mounted on a Nikon D90 at 1100 ISO and 1/1600, using the Legacy2Digital modified adaptor. 12.3 Megapixel original cropped and adjusted for exposure using Aperture 3. Note the reflection in the left eye at 1:1 [Click image to view 1:1 resolution].


Test target (Grevillia Banksii) using the 200 mm f/2.8  APO manual focus lens mounted on a Nikon D90 at 640 ISO and 1/1600, using the Legacy2Digital modified adaptor. 12.3 Megapixel original cropped and adjusted using Aperture 3 [Click image to view 1:1 resolution].


Test target (Lemon blossom) using the 200 mm f/2.8  APO manual focus lens mounted on a Nikon D90 at 1600 ISO and 1/1000, using the Legacy2Digital modified adaptor. 12.3 Megapixel original cropped and adjusted using Aperture 3 [Click image to view 1:1 resolution].



Test target (Plum blossom) using the 200 mm f/2.8  APO manual focus lens mounted on a Nikon D90 at 400 ISO and 1/3200, using the Legacy2Digital modified adaptor. 12.3 Megapixel original cropped and adjusted using Aperture 3 [Click image to view 1:1 resolution].



Test target (Buttercup oxalis blossom) using the 200 mm f/2.8  APO manual focus lens mounted on a Nikon D90 at 1100 ISO and 1/1600, using the Legacy2Digital modified adaptor. 12.3 Megapixel original cropped and adjusted using Aperture 3 [Click image to view 1:1 resolution].


Test target (Sage blossom) using the 200 mm f/2.8  APO manual focus lens mounted on a Nikon D90 at 1600 ISO and 1/1600, using the Legacy2Digital modified adaptor. 12.3 Megapixel original cropped and adjusted using Aperture 3 [Click image to view 1:1 resolution].


Test target (Australian Magpie) using the 200 mm f/2.8  APO manual focus lens mounted on a Nikon D90 at 900 ISO and 1/1600, using the Legacy2Digital modified adaptor. 12.3 Megapixel original cropped and adjusted using Aperture 3 [Click image to view 1:1 resolution].



Test target (Spotted Turtle Dove) using the 200 mm f/2.8  APO manual focus lens mounted on a Nikon D90 at 800 ISO and 1/800, using the Legacy2Digital modified adaptor. 12.3 Megapixel original cropped and adjusted using Aperture 3 [Click image to view 1:1 resolution].

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Test target using the 200 mm f/2.8  APO manual focus lens at f/8.0 mounted on a Nikon D90 at 200 ISO and 1/1600. Uncorrected  12.3 Megapixel original. This configuration produces the same angular coverage as the lens with one 2XN teleconverter. Handheld shot from ~2.5 metres [Click image to view full size].



Test target using the 200 mm f/2.8  APO manual focus lens at f/4.0 mounted on a Nikon D90 at 250 ISO and 1/1000. Uncorrected  12.3 Megapixel original. This configuration produces the same angular coverage as the lens with one 2XN teleconverter. Handheld shot from ~2.5 metres [Click image to view full size].

x

Test target using the 200 mm f/2.8  APO manual focus lens at f/4.0 mounted on a Nikon D90 at 800 ISO and 1/400. Above, uncorrected  12.3 Megapixel original, below enhanced using Aperture 3. This configuration produces the same angular coverage as the lens with a 2XN teleconverter. Handheld shot as the moment produced by the lens was judged to be great enough to damage the tripod clamp [Click image to view full size].

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x

Above: Test target using the 200 mm f/2.8  APO manual focus lens at f/8.0 mounted on a Nikon D90 at 320 ISO and 1/500. Uncorrected  12.3 Megapixel original. This configuration produces the same angular coverage as the lens with one 2XN teleconverter. Handheld shot from ~2.5 metres [Click image to view full size]; below: 1:1 crop of same, note the ant at full size to the upper left of the lime fruit - the left antenna is distinguishable, but the eyes are not. Third image is enhanced using Aperture 3.



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Sekor A 200 mm f/2.8 APO Lens Test Shots (645AFD Film)


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Cat using the 200 mm f/2.8  APO manual focus lens at f/4.0, 645AFD, with Fuji Pro 160C. Below cropped 1:1. Scan is 1300 PPI.

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Rye Beach / Cape Shanck using a 200 mm f/2.8  APO manual focus lens at f/4.0, with Provia 100F. Below cropped 1:1. Scan is 1300 PPI.



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Rye Beach using a 200 mm f/2.8  APO manual focus lens at f/4.0, with Provia 100F. Below cropped 1:1. Scan is 1300 PPI.



Sekor A 200 mm f/2.8 APO Lens Test Targets (645AFD Film)



Test target using a 200 mm f/2.8  APO manual focus lens at f/2.8  in an 800 mm arrangement with two stacked 2xN teleconverters, with Fuji Pro 160C. Above is uncorrected original reduced from 1300 PPI scan, below same after correction for chromatic aberration using Photoshop.





1:1 crops of test target using a 200 mm f/2.8  APO manual focus lens at f/2.8  in an 800 mm arrangement with two stacked 2xN teleconverters, with Fuji Pro 160C. Above is uncorrected original at 1300 PPI scan resolution, below same after correction for chromatic aberration using Photoshop.




Photos and text © 1997 - 2013 Carlo Kopp



Computer Science, Engineering and Systems Publications List Information Warfare, Hypergames, Systems Research Ad Hoc Networking Research Computer Architecture Research - Password Capability Systems Industry Publications Industry Hardware Design Projects Interesting Papers Photo Galleries Biography Email Carlo GOTO Home
Artwork and text 1994 - 2010 Carlo Kopp; All rights reserved.
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