Optical Formula for Yashinon DX 1.4

ts1000

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Decided to remove fungus for Yashinon-DX 1.4 (Serial 541191xx)
After putting it back together, the infinity focus is wrong (seems like center is in focus, but the outside circle is just a blur).
Therefore, I am thinking I put one of the lens elements in an opposite way (although it seems impossible to be wrong as the surfaces do not fit otherwise).

Wanted to ask if anybody knows the optical formula / chart for the lens elements for this lens, so that I can check and redo my assembly if necessary.
 

Donald Qualls

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Spacing between groups being significantly wrong could do that too...
 

ic-racer

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Nice lens. Not easy to find. Take care of it. I believe the two rear-most elements are similar but could be accidentally interchanged.
 

dynachrome

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If I remember the time line there was the DX, the DS and the DS-M. I have all of those f/1.4 models, two of the DS-Ms. The DS-M has improved coating and was the final series of Yashica M42 lenses. I don't really care for the Yashica M42 cameras but I like some of their M42 lenses. The standard lenses without an A/M switch are no problem on Spotmatics and Mamiya DTL cameras. They can even be used in stop down metering mode with the Auto XTL/Auto X1000 with the Mamiya P adapter. They are not as useful even with adapters on Minolta and Canon manual focus cameras.
 
OP
OP

ts1000

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@ic-racer, @Donald Qualls thank you! I had a spacing ring before the 2nd to last element, it should have been before the last element.
Now getting infinity focus.

This is not the sharpest lens at infinity (at least in my brief testing today), so will host it on my Vivitar 250/SL for the 'middle age' portraits duty with Ilford HP5+.
This duty however, will not exhibit all the great qualities of this lens, particular its ability for nuanced and neutral color reproduction.
I need slide film for that, which I do not do yet.

thank you again!
 
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Donald Qualls

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Glad you got it straightened out. Anything f/1.4 is probably worth keeping working...
 
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