How do I get a "known good" J-9 for M-mount?

[tofagerl]

Aaaaaand wikipedia... 🙂

 

[stevebrot]

The lens registration distance is the same.

It's the internal helicals which are slightly different...

The lens registration is not quite the same, at least not based on public specification. FSU registration is 1mm deeper than Leica. Fortunately it is possible to shim to make up the difference for use on non-FSU cameras. Strangely, there are plenty of reports of users that have had no issues on their non-FSU cameras and are using the FSU lenses without modification.

Unfortunately, there are also numerous reports that some lenses when properly shimmed and collimated at infinity are no longer properly coupled at closer distances and vice-versa when used on non-FSU cameras. Variance from Leica standard in the pitch of the focus helicoid has been proposed as the possible reason. I suspect that is why FSU LTM cameras have provision for adjustment of the rangefinder cam at 1m distance.

I have both a Jupiter-8 and Jupiter-12 (no J-9) and have had good luck with both lenses on my Zorki 4K and FED-2. I recently got a Canon P and am finishing the initial test roll on the camera with these two lenses. I have my fingers crossed that they will work without modification. 😉 One can only hope, right?


Steve

 

[Roger Hicks]

There are at least three separate questions here:

Your expectations

The seller's expectatons (which may be higher or lower than yours)

The maximum quality of which a 75-year-old design is capable.

Cheers,

R.

 

[Sonnar Brian]

I currently have three J-9's, two from the 1950s and one from 1975. Sold a fourth, also from the 70s. The 1970s lenses are soft by comparison with the 1958 lens shown here. But, they make good portrait lenses. They are much lighter than the Nikkor and Canon 85's, much lighter than my 90mm Summicron.