Jupiter-8 Lens

[john341]

Does anyone know what is the significance and/or rarity of the J8 52mm lsm lens? The focal length is hardly significant however was this lens designed with a particular camera in mind? Little things like this intrigue me...

 

[blazejs]

As far as I know all Jupiters 8 are 52 mm. However there's 50/2 engraved. Does your have 52/2 engraving?

Link: http://www.ussrphoto.com/Wiki/default.asp?WikiCatID=26&ParentID=2&ContentID=335&Item=Jupiter%2D8+50%2F2+Chrome

 

[ronnies]

I believe the original Zeiss lens which the Jupiter 8 is a copy of was designed for the Contax rangefinders.

Ronnie

 

[ZorkiKat]

I don't think that there is really lens marked "50mm" which really has a true FL of 50mm. The FL value engraved on lens ID rings is almost always a rounded figure.

 

[john341]

52/2

52/2

As far as I know all Jupiters 8 are 52 mm. However there's 50/2 engraved. Does your have 52/2 engraving?
Yes, this one from the 1950s is engraved F2 52. It is unusual as my other four or so Jupiters are engraved 50/2. I think later Jupiter M for the Kiev went to 52mm as did the Helios...I thought that maybe this one had been built for a particular camera...interesting.
Thanks for your thoughts

 

[Sonnar Brian]

I've seen lenses for the Lab engraved with the true focal length rather than the rounded one. A Wollensak Raptar for CRT's engraved "51mm". For technical use having the real focal length is important.

If it is an older 1950s J-8, the typical marking would be "5cm". Engraving it 52mm is somewhat rare, perhaps special order or "Cherry Picked" for technical work.

All speculation on my part, based on old lenses around the lab.

 

[dee]

I believe that most early lenses were longer than 50mm because it was easier to design - some would be marked 50mm when it became a normal length ... it became a nominal length .
Two , later , 1979 / 80 Jupiter 8 m lenses are marked 53 mm whereas the earlier J 8s are 5cm .

 

[Rui Morais de Sousa]

Hi,
I also own two Jupiter 8 lenses.
One in LTM from 1956 (in a Zorki 3C, also from 56) that says 5cm, and one in Kiev mount Jupiter 8M from 1980 (in a camera from same year) that says 2/53 (without specific metric unities, beig of course mm...).
By the way: does anyone knows the difference between J8 and J8M? My J8 from 56 is also coated. You can see it clearly in the color and it has the symbol that means so...So I think that should not be the difference.
Cheers,
Rui
AL-MOST-LY PHOTOGRAPHY

 

[ItsReallyDarren]

Hi,
I also own two Jupiter 8 lenses.
One in LTM from 1956 (in a Zorki 3C, also from 56) that says 5cm, and one in Kiev mount Jupiter 8M from 1980 (in a camera from same year) that says 2/53 (without specific metric unities, beig of course mm...).
By the way: does anyone knows the difference between J8 and J8M? My J8 from 56 is also coated. You can see it clearly in the color and it has the symbol that means so...So I think that should not be the difference.
Cheers,
Rui
AL-MOST-LY PHOTOGRAPHY

To the best of my knoweledge the J8-M was a slightly reworked version that gave click stops on the aperture barrel. Not sure about the optical formula.

 

[brachal]

To the best of my knoweledge the J8-M was a slightly reworked version that gave click stops on the aperture barrel. Not sure about the optical formula.

The 8-M introduced click stops. I believe the optical formula was simplified, with two cemented elements being replaced by a single element.

 

[Rui Morais de Sousa]

Thank you for your replies, and I think that you are correct about the click stops:my Kiev J8M has click stops! (It reminds me of the old Nikkors with full stops, no half stops...).
Cheers,
Rui

 

[Sonnar Brian]

The diameter of the optics is slightly bigger on the J-8M. I tried to swap elements once with an older lens. Did not work out.

 

[john341]

J-8 5cm or 5.2

J-8 5cm or 5.2

Now that was an interesting comment..when I receive this lens I will measure its diameter-I've looked at all my J8s and they are 5cm..thanks for comments. My next job is to clean-up and lube a j3 which has a rough focus ring...cheers from Oz

 

[Sonnar Brian]

The J-3 should be an easy job.

http://pentax-manuals.com/repairs/j3service.pdf

 

[john341]

Easy for some

Easy for some

The J-3 should be an easy job.

http://pentax-manuals.com/repairs/j3service.pdf

Thanks..I have this document, but I would ask, when the screws from the focus ring are removed, oes the ring slip or screw off? Probably a stupid question but I haven't pulled one apart before/Thanks in advance

 

[Sonnar Brian]

That is a GOOD question.

The Focus ring pulls straight off on the J-3, except perhaps the very earliest ones.

This design is, in my opinion, and improvement over the Wartime CZJ Sonnars in LTM. On the German lenses, and early FSU lenses, the focus helical has to be removed from the mount before the ring can be slipped off toward the REAR of the lens. The J-3 changed it so the Focus Ring slides off to the front of the lens.

 

[john341]

J3

J3

Thank you again-I feel more confident approaching this job now. Looking forward to a smooth focus!