Leica Jupiter-9 85/2, Contax/Kiev mount with Amedeo Adapter

[Brian]

I fine tuned the focal length by moving the rear group in closer to the front elements, and then set the main shim for use with the Amedeo Adapter. Focus is good close-up and wide-open across most of the range.

Wide-open at 1.15m, on the M8.

Join to see EXIF info for this image (if available)

 

[VINCETAN]

Very cool. I just purchased a Black J-9 in LTM mount. Can't wait to try it.

BTW, is the image cropped?

 

[Brian]

This is one the M8, using 16-Bit Raw mode. No Cropping, full-image, Reduced to 1024 length via Lightroom. The 85mm FL works out well on the M8.

 

[VINCETAN]

I just got my J-9 black in LTM mount.

 

[Brian]

You will not have to worry about focus with the mirrorless camera. If you ever get an RF- the Black version has a secondary shim for the rear group, makes it easier to shorten the focal length.

 

[carlb]

Nice lens! (Prairie dogs must have been thinking envious thoughts about it.)

 

[VINCETAN]

Straight off the camera, the color is not what I was hoping for. A little tweak in LR5 really helps. For $150, not too bad. I will probably sell this and a few others when I find a 75mm apo

 

[carlb]

Ah, gotchya.

 

[Corkey69]

Brian,

How much do you think the shim on a ltm J9 needs to be reduced to improve performance on the M9 (yes, I know I will have to do the main shim too).

I have a nice example and would like to put it back into use - any advice you can offer would be most welcome

Regards
John Neal

 

[Brian]

John- some rough measurements of the focal length of the front group and of the rear group, required changing in spacing to match the Leica standard: was ~3mm. The "lens maker's formula" applies, the front section of a Sonnar is "about" 2.5x times the focal length of the finished lens; the rear group of a Sonnar is about the same focal length as the finished lens. Spacing between the front and rear group sets the focal length of the finished product. I managed "2mm ~ 2.5mm" by removing the rear shim and polishing down as far as possible. The main shim has to be reduced by "about" the same amount to keep the rear element in position.

and John, great to see you here!

 

[Corkey69]

Brian,

Thanks - my example has a fairly thick shim - say about 2.5mm and I already tried swapping that out with a 1mm replacement to good effect. Maybe I could go even thinner or remove it entirely? I found the shim was exactly the same diameter dimensions as one removed from a J3, which was handy.

I don't have a M240 for live view, but Icould try it on the XE-1 I guess, otherwise it is trial and error on the MM.

Brian, thanks for the welcome - I'm glad to be here

 

[Brian]

Each lens is going to be slightly different- but if you can get away with removing the shim entirely AND be able to screw the optics module far enough into the focus mount to get to infinity- I would try that.

 

[Corkey69]

Brian,

Guess what I'm going to be doing over the holiday?

Thanks for the advice