Jupiter-9 F/2,0-85mm versus Leica Summarit F/2,5-75mm

[jc031699]

Just wanted to add that the original (pre-war and war-time) Sonnar 85/2 has similar flare. I found that one of the differences between the versions that flared a lot and those that flared a little was the presence (less flare) or absence (more flare) of a rifling like texture in the rear barrel that engages with the Contax bayonet.

It seems to me that the image circle of both the Jupiter-9 and the Sonnar 85 is much larger than required - causing a lot of extra light to bounce around inside the camera and optical system. For example both lenses can be used on the Fuji GFX (close to 645) with no vignette

To further reduce the flare you could consider gluing in some soft light-absorbent material such as blackened linen or similar. I've done this and had decent results.

Terrific insight, thank you. The adhesive flocking did help a lot.

 

[jc031699]

A few of my points to the respected community -
Jupiter 9 often has flare with loss of contrast, this is mainly due to poor blackening of the inside of the housing at the back of the lens (or the paint has simply peeled off over time)
By changing (increasing or decreasing) the distance between the last lens and the penultimate one, you can increase the sharpness in the near field (up to 3-5 meters) of focusing.

Would this remove the ability to focus to infinity? How is the modification done?

 

[Brambling]

Would this remove the ability to focus to infinity? How is the modification done?

Oh no!
In your case, consider this a bad recommendation.
I remember - it was a very complicated option (I got the lens as a set of parts), and I couldn't repeat it on other Jupiter 9s.
In general, in my opinion, any changes and repairs should be reversible, with the ability to return to the original position, with preliminary and final tests and checks.
And if the lens is too expensive for you, then all repairs and replacements should be done by specialists.
I will be very glad if my words push you to the right decision, whatever it may be.)

 

[Brambling]

I beg you - point me with your finger, please, where on the site were different options for blackening different surfaces discussed?

 

[jc031699]

I beg you - point me with your finger, please, where on the site were different options for blackening different surfaces discussed?

Just in my original post up above in this same thread. And Brian mentioned blackening the surfaces helping with his flare on the Triotar 85/4.