Lens review: Chiyoda Kogaku Chiyoko Super Rokkor 1:2 f=5cm C (Minolta) Japan LTM/LSM/m39

MSR5020exterr77

Chiyoko Super Rokkor 1:2.0 f=5cm (Minolta) Japan LTM parameters:

Name engraved on lens Chiyoko Super Rokkor 1:2 f=5cm C
f[mm] 50
A max [1/f] 2
A min[1/f] 22
Number of blades 10
Lens design [el.] 7
Lens design [gr.] 6
Filter thread Ø front(rear)[mm] 40.5 or 43
closefocus[m] 1
Max. diameter[mm]
Lengh min/max [mm]
Weight[g] 260

Additional information:

  • This lens was introduced in 1954 with new Minolta 35 Model II camera
  • Collectors know at least 5 editions of this lens with different combinations of: filter threads (40.5 – 43mm), different min F (16 – 22), typed or not red “C” letter, serial numbers ranges (Much thanks to Andrea Aprà for details)
  • The reviewed lens was released at the end of 1955 or, even more chances, in early 1956 (serial is 1302648, filter thread 43mm, f/max 22, red ‘C’ is presented)
  • This lens arrived directly from Japan

 

Lens exterior:

(Please, forgive me the dust on the lens, I never have the patience to clean objects for close-up photo sessions)

 


Lens code name – Amira アーミラ

Amira (Āmira) is a half-demon/half-angel. She is accused for stealing the God Key and is being hunted by humans, gods and demons alike.

 


Resolution – close distance:

Test description: target is a 10×15 cm picture (printed, glossy photo paper), fixed on the wall by scotch. Distance is 1.8m. Camera Sony A7II (24mpx, full frame) was fixed on the tripod and managed remotely with computer display as a viewfinder. All groups of shots were repeated 9 times for every target position on all apertures from fully opened up to F16, ISO-100, WB – same for all shots. SteadyShot – OFF. Focus was manually corrected for each shot. After all needed shots have been taken for one target position – I moved the target to the next place.

test_scene_view300x200

Main idea – to exclude the field curvature affect on so close distance.

Of course, I can’t be absolutely accurate, but so many repeats of shots – 4 for corners, 2 for long side, 2 for short side are giving me insurance that test results are correct.

Finally, pictures were converted from ARW-files in Capture One with default settings, cropped for 300×200 px elements, combined into diagrams and exported into JPEG-files.

Scene preview:

Minolta5020LTM_scene_preview

Original target image (printed in horizontal orientation on 10cm X 15cm glossy photo paper)

Amira_15

Test results (selected version, easy to compare – 4 positions):

Minolta5020LTM_SHORT

Test results (full version – all 9 positions):

Minolta5020LTM_FULL


Resolution – long distance:

Test description: Camera Sony A7II (24mpx, full frame) was fixed on the tripod and managed remotely with computer display as a viewfinder. Targets (buildings) were fixed by gravity power on the distances in more than 200 meters. All shots have been taken with apertures from fully opened up to F16. ISO-100. Shutter Speed – depends on light (camera A-mode), WB – fixed and the same for all shots. SteadyShot – OFF. Focus was manually corrected for each shot to exclude focus-shift affect.

Finally, pictures were converted from ARW-files in Capture One with default settings, were cropped for 300×200 px elements, combined into diagrams and exported into JPEG-files.

Scene preview:

MSR5020long_dist_F5_6_preview

Test results:

Minolta5020LTM_LONGDIST


Vignetting:

(frames scaled – 300×200)

Minolta5020LTM_Vignetting


Geometric distortion:

(frame scaled 1200×800)

MSR5020_geometr_DSC04867


Coma aberrations:

(100% crops – 300×200)

Minolta5020LTM_coma_aberr_


Chromatic aberrations:

(100% crops – 300×200)

Minolta5020LTM_chrome_aberr_


Close distance bokeh:

Test conditions: lens was focused on to minimal distance 1m, plants were fixed in 3m distance from camera in front of the window with bright light from outside.

(frame scaled 1200×800, bokeh covers the frame partially)

MSR5020_bokeh_close_3crops


Long distance bokeh:

Test conditions: lens was focused on half distance on the scale 2m, houses were fixed in infinity distance on the ground.

(frame scaled 1200×800)

Minolta5020LTM_bokeh_far_4crops


Light dots bokeh:

Test conditions: lens was focused on to minimal distance 1m, diodes were fixed in 3m distance at the dark background.

Note: a lot of similar tests with another 50mm lenses for same or close conditions are presented on the site, so you can compare easily. Please, read other articles.

(frame scaled 1200×800)

MSR5020_dots_close_4crops


Light dots long distance bokeh:

Test conditions: lens was focused on to minimal distance 1m, lights were fixed in more than 200m. Such scenes can’t be meet often, so this is demonstration of extreme conditions. In most cases of real life photography the blur level will be less.

(frame scaled 1200×800)

MSR5020_dots_far


Another resources with tests and reviews:


My overall conclusion about the Chiyoda Kogaku Chiyoko Super Rokkor 1:2 f=5cm C:

AvatarPlankMSR5020

This lens can make masterpiece from any photo independently of photographer skills. Just one thing: photographer should forget about sharpness and should remember about  aberrations – technical IQ is really not so good as we expected for today. Not everyday lens, but it would be good to have it in the bag for occasional photos which are required unusual drawing of the scene. It can’t be recommend for all  because it’s too specific. Looks like a toy which can transform owner into famous photographer, but in very rare cases, so better to don’t hope for this. Feel free to take photo at wide opened, because closing for 1-2 stops won’t help to get the sharpness over the full frame. Close it at least to F8 for landscapes, but, to be honestly, better to change it for another lens. Don’t forget to get a lens-hood. Can be recommend to anyone who aspires to add expressive bokeh to their photos – in this case Chiyoko looks as very good choice.


 

This lens took part in the battles:

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