The Koni-Omega 58mm/60mm Lenses (Yes, again!)

[JRG]

Mr. Google and I have checked the archives here and elsewhere regarding the wide-angle lens for the Koni-Omega RF system. To review quickly, there were two such lenses, a 60mm f/5.6 and a (later) 58mm f/5.6. The issue is whether these were in fact the same lens.

It's a popular belief that they were. Here's a sample RFF thread where the consensus seemed to arrive at that position. (And there are some interesting hypotheses as to why the designation was changed from 60mm to 58mm.)

http://www.rangefinderforum.com/forums/showthread.php?t=10841

Further, the article at Camerapedia says this: "There is a 58mm f/5.6 wide-angle lens. The actual focal length is 60mm but for various reasons is marked 58mm."

(http://www.camerapedia.org/wiki/Koni-Omega#List_of_lenses)


Now thanks to Mr. Butkus, there are complete user manuals available for most of the K-O cameras. Here's the manual for the early K-O Rapid cameras:

http://www.butkus.org/chinon/koni-omega/koni-omega_rapid/koni-omega_rapid.htm

And here's the manual for the later K-O M and Rapid M cameras:

http://www.butkus.org/chinon/koni-omega/koni-omega_system/koni-omega_system.htm

And finally, here's the manual for the Rapid 100/200 series:

http://www.butkus.org/chinon/rapid_omega_100-200/rapid_omega_100-200.htm

(Thanks, Mr. Butkus!)

On p.17 of the K-O Rapid manual (first Butkus link), you'll find lens diagrams and descriptions for the available lenses. In the M/Rapid M and 100/200 manuals (2nd and 3rd Butkus links), the same information appears on p. 21 of the file.

OK, here's the deal: The Rapid manual shows the lens diagram for the 60mm f/5.6: The design is six elements in four groups (6/4). The M/Rapid M and 100/200 manuals show the lens diagram for the 58mm f/5.6. The design is eight elements in four groups (8/4).

Both designs are of a symmetric type, but 8/4 is different enough from 6/4 to support the conclusion that the design was re-computed when the lens description changed from 60mm to 58mm. And in that case, the Camerapedia claim about the 58mm lens,

"... The actual focal length is 60mm but for various reasons is marked 58mm."

would seem to be wrong.

Thoughts?

 

[raid]

I sold my 58mm lens with finder many years ago, so for me this is academic.

 

[KoNickon]

Wow -- a great piece of sleuthing. I have the Hexanon version, and I think it's the 58mm (8 element) version, but I would have to confirm.

It would be very interesting to see a comparison between the 6 and 8 element versions.

 

[JRG]

Wow -- a great piece of sleuthing ...

Thanks, but all I did was stare at the owner's manual for a bit. 😉 (And there are other interesting tidbits to be found there, but I haven't yet finished my "sleuthing" on that front.)

But isn't it sort of puzzling that with all the discussion this issue has triggered, no one looked in the owner's manual?

 

[KoNickon]

I'm amazed no one noticed this before you -- which doesn't detract from your perceptiveness. (Of course, why someone would be looking at the two different owner's manuals is another story! But thank goodness for Mr. Butkus, indeed.

 

[Abbazz]

But isn't it sort of puzzling that with all the discussion this issue has triggered, no one looked in the owner's manual?

This reminds me of the pixel peepers on some forums endlessly arguing about the image quality of the Super-Takumar 135/3.5 without ever realizing that there are two distinct variations of this lens, the earlier with 5 elements (product number 43540) and the later with 4 elements (product number 43541).

Cheers!

Abbazz

 

[furcafe]

Everyone knows that real men, & you have to be a real man to lug around a Koni on a hot summer day, can't be bothered to read no stinkin' instruction manuals. 😛

But isn't it sort of puzzling that with all the discussion this issue has triggered, no one looked in the owner's manual?

 

[JRG]

Everyone knows that real men, & you have to be a real man to lug around a Koni on a hot summer day, can't be bothered to read no stinkin' instruction manuals. 😛

Yeah, I s'pose that might be it ... 🙄

 

[raid]

I wish I had kept the 58mm lens. It was a good lens.

 

[randy stewart]

Koi-Omega Wides

Koi-Omega Wides

I first got into K-O many years ago, buying the 60mm lens. This lens was not impressive, i.e., not critically sharp. I bought a 58mm, which is razor sharp. so much so that I suspect that my 60mm was also just a bad copy of the lens. The 60mm is a knock-off of the Angulon; the 58mm is based on the Super Angulon design. The sale values on the K-O bodies and lenses (except 135mm) are so low that I've kept my system rather than selling it off. Still good to go on a moment's notice.

 

[Tim Hicks]

KO 58mm

KO 58mm

I don't have a Koni Omega camera but a couple of years ago I bought a very reasonably priced 58mm that had no matching viewfinder (the reason it was cheap I guess) and then refitted it in a suitable Copal shutter. It now fits on my Baby Graphic and works very well. I later did the same with Mamiya Press 65mm too, similar one without its finder.