Jupiter 3

[Lear]

Hi all,

I just got a jupiter 3 from a friend, the lens feels solid and smooth, chrome, dont know the year. (if tis the first 2 digits of SN than its 73)

Looks goos and seems to funtion well cant try it yet, but there are 2 things that bother me:

1. Focusing goes about 0.3mm past infinity mark on the focusing ring, should I worry?
2. F stop index is 2mm to the right in reference to de 1.5 mark and I can still see the blades (so I would think it does not open all the way) or its normal to see them a few mm even wide open?

So....... any manual to take this lens apart to I can get the indexes on spot?

What quality shold I expect?

Thanks

 

[back alley]

diego, do a search as there is much info here on this lens.
brian sweeney has taken them apart etc. and others have experience with them also.

joe

 

[Lear]

I just found Brians Post on this lens, most informative 😀

 

[Sonnar Brian]

You should be able to turn the aperture ring until the blades are all the way open and out of sight. I suspect it will be past your mark. Every time you adjust the J3 focus, the lens screws in/out differently and rests at a different point. Once you have found the correct focus, you have to undo the aperture ring and tap out new holes to get the index to line up. That is IF the set screws survice, They tend to blow out when you attempt to remove them, or crack when you tighten them back up. I used double sided tape to hold it back on one of mine, the one made from left over "broken" parts.

 

[Lear]

actually I cant get the blades to go in all te way. There is a screw in kind of a chanel that tops leaving about 1.5mm of blades showing. I will try exposure on fil before opening it up to see if its right or not.

 

[Sonnar Brian]

I have not seen that happen before, I've gome through 7 J-3's in the last 3 months.

The aperture ring has three set screws. Once those are out (and hopefully do not break), the aperture ring unscrews.

 

[Lear]

Playing around with the lens, trying to thread it in diferent points, I got the one that matches the index mark, and guess what, it goes from the 1.5 line and tops at the 22 line. So I guess that is fine. If I have the same luck with the focusing I consider myself lucky on this one.

thanks for your pointers Brian.

 

[Paul Connet]

actually I cant get the blades to go in all te way. There is a screw in kind of a chanel that tops leaving about 1.5mm of blades showing. I will try exposure on fil before opening it up to see if its right or not.

I have two J3's at hand, and on both, the aperture blades can still be seen when fully open to f1.5. The blades do form a complete circle but are visible if you shine a flashlite in from the front. You will do yourself a favor by shooting first to see if you have a problem.

Regards, Paul C.