Other/Uncategorized CHIYODA KOGAKU (MINOLTA) 5cm f1.8 Super Rokkor LTM fitting

Other Screw mount bodies/lenses
Can somebody info regarding how many aperture blades there are on:

- Super Rokkor 50mm f/2
- Super Rokkor 50mm f/1.8
- Super Rokkor 50mm f/2.8

Thanks.
 
i have this lens (50mm F1.8) I absolutely ADORE it on my M5 and M8. I like it more than my pre-ASPH Summilux 50mm.

a pic on my M5:

4.jpg


another:

leica_m8_and_m5.jpg


here are some of the photos i've taken with it and my M8:
http://500px.com/photo/20902003
http://500px.com/photo/20832819
http://500px.com/photo/20408747
 
Recently I read somewhere hinted that Chiyoko 50/1.8 is a copy of Leica 50/2 Summar. It doesn't explain further which Summar. I know there are collapsible and rigid body Summar.

Perhaps somebody can explain the optical design of those lenses and maybe point out if there is any similarity in design principle. Thanks.
 
Super Rokkor 50mm f1.8 - optical design

Super Rokkor 50mm f1.8 - optical design

The Super Rokkor 50mm f1.8 lens has a 6-element, 5-group Planar-type design. Compared to the Zeiss Planar, the first cemented group in the Super Rokkor is split. See the attached scans, which include the cover from the Japanese-language book.

This configuration, with wide variations in geometries, was used by other lens makers for fast 50's and short teles. Six-element, 5-group Plane-types with a split second cemented pair were also common (Fujinon 50mm f2, for example). I don't know who came up with these Planar variations first, but I'm sure the idea to do so occurred to many. When it comes optical designs, it's usually safe to assume Carl Zeiss did it first.

Cheers,

David
 

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Thanks David for the valuable information.

I wonder how many unit of the Rokkor 50/1.8 were actually produced. AFAIK it was only made during 1956-1957 in small number.
 
I recently acquired one Rokkor 50/1.8 with SN: 1300422. It has metric scale, f/ stop to 22.

One thing I noticed first of all is very fast transition between in-focus and out-of-focus area. Sharpness is high.

Lens coating has golden brown tint, rather similar to Canon 50/1.4.
 
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