[Leica] New Jupiter arrives

[dlridings at gmail.com (Daniel Ridings)]

On 8/24/05, pswango@att.net <pswango@att.net> wrote:
>  Hoping for the best, though I have been warned about uneven QC on this 
> model.
>  We'll see.  Anyway, it only cost $20 plus shipping.

I hope it works out, Phil.

Quality control can be many things. My limited exerience (half-a-dozen
lenses) has been that the glass is just fine. But there are shims in
the lens body to gauge how far the lens is from the film plane
(Contax/Kiev's are not as solidly built as IIIc, IIIf, and later
Leicas, where the body is one piece). So the body thickness could vary
a bit. To counter this, the shims in the lenses could be thinner or
thicker accordiningly.

And ... as Dante Stella has demonstrated, the dimensions were never
the same as Leica, not even in the Zorkis and other screw-mounts, to
start with.

It appears that the factory just threw in a shim. Sometimes it will be
too thick, sometimes too thin. This will cause focus to fall a little
in front or a little in back of what you think you are focusing on.

The Jupiter-8's seem to be consistently wrong, if they are wrong, so
once you've figured it out, you just adjust the rangefinder image
slightly to push the lens further away or closer to the film plane.
It's usually just a tad.

But if it is off, it can result in slightly out of focus, soft images.
But, as I said, this doesn't necessarily mean anything is wrong with
the glass. Just the dimensions.

So take some close-up shots at wide-aperture to see where the focus is
falling. Mine is just ever so slightly off (slightly behind). So I
focus and then move the focus ring a slight tad closer. Actually, it's
so close that beyond 1 meter, I don't usually bother with it. At two
meters the little depth of field as f2.0 is enough to compensate.

Now Jupiters-12's .. that's another story. They can be pretty far off.
Don't ask me why.

Enjoy! I hope it works out for you.

Daniel