Jupiter 8 reassembly question

[dreilly]

Hi All,
I'm cutting my lens tinkering teeth on an old silver Jupiter 8. And I made a mistake, loosing track of where exactly the focusing ring threads down. Any which way it ends with the red mark at infinity...but on one thread it goes a bit below 1 Meter the other way, and the next nearest thread I could find stops the red mark at 1.2 meters.

Can someone educate me here? Which should it be?

thanks!
doug

 

[wlewisiii]

Bit below 1 meter on the black one on my Canon IV.

Hope this helps,

William

 

[reagan]

Without having it in front of me, .......? But normally the arrow should stop just below the 1 meter mark. How far? Good question. I have two older J8s ('50s), one stops just a hair past 1m, the other goes quite a bit further below 1m. Both seem to work fine. A third I have, a 63 model, stops somewhere in between the other two. It too seems to be working fine.

Someone else here might be able to give us specs on "exactly how far below 1m" it should stop. Good luck. I really like the J8s!!

 

[dreilly]

Thanks, can anyone else check their J-8 and see where it ends?

 

[dreilly]

Oops, you beat me too it. That's three for below the 1 meter mark...okay, there's only one option in that range that I can find. Thanks all, again.

doug

 

[peterc]

I have the black J8. At closest focus (looking down on the lens mounted on the camera) the 1m mark is just to the right of the 2.8 DOF line.

Peter

 

[dreilly]

Hmm, mine's much farther than that...out between the 8 and 11 line.

 

[wlewisiii]

Mine is as Peters - 1 meter just barely to the right of the 2.8 mark.

William

 

[peterc]

Mine is as Peters - 1 meter just barely to the right of the 2.8 mark.

Guess that means ours are correctly adjusted ... or the guy who checks them was equally drunk.

Peter

 

[Kim Coxon]

Hi,
The black J8's are a very different construction from the silver ones. Because of the way they are put together, there may well be slightly different places where they stop. The important thing is to get the infinity right. As long as this is correct, I wouldn't worry about the other end, the difference is small.

Regards
Kim

I have the black J8. At closest focus (looking down on the lens mounted on the camera) the 1m mark is just to the right of the 2.8 DOF line.

Peter

 

[reagan]

Okay, compared to the DOF markings... BTW, dreilly, mine are all silver (or "white") jupiters. The 1m mark on the '55 is way over just past f11... the '56 is a hair past the center arrow and the '63 is dead nuts on f5.6. See? That's what I like about FSUs ~ consistency.
And yeah, mine all stop right on infinity.

 

[dreilly]

Thanks, I did a little testing at infinity and mine is where it should be...yeah, pretty consistent stuff. But fun to work on, too!

Thanks everyone!