Archived posting to the Leica Users Group, 2000/10/16

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Subject: Re: [Leica] Jupiter lens 'tests'
From: Dante A Stella <dante@umich.edu>
Date: Mon, 16 Oct 2000 07:57:45 -0400
References: <005a01c03754$7516e870$4d02a8c0@neurosoft.lan>

Looking at a couple of 20x30 sections, it is interesting that the
Jupiter-3 and its Japanese equivalent, the Canon/Serenar 50/1.5, which
has 13-16 blades (I am losing count), both exhibit an odd "donut-bokeh"
with certain specular highlights (e.g. waxy leaves on trees that are in
front of the plane of focus). It is interesting because the 1936 50/1.5
Sonnar does not exhibit this.  Maybe the Opton Sonnar does.  I would
guess that this difference is attributable to the coatings.  If I can
get my scanner hooked up again (damn SCSI to USB connections), I can
email you parts of the prints.  The coatings don't seem to add much to
the on-axis performance of this lens, like you said because there are
few air-glass surfaces.  I think in practical terms the contrast
difference on a sunny day is 1/2 grade.

As for the astigmatism, there is little - there is a lot more in the
50/2 Jupiter-8, which likes to make teardrops at down to about f/4.

The 50/1.5 is a good performer if your  other choice is shelling out
megabucks for a Summilux or other 50/1.2 lens.  But the Jupiter-3 has
some practical shortcomings that make life interesting

- -- extensive use of aluminum, including a lens barrel that deforms
easily and binds
- -- collimation via a raw aluminum disc, which is subject to compression
- -- lack of click stops, meaning that you have to periodically check the
aperture ring
- -- extremely soft lens coatings (is a Jupiter-3 free of scratches when
it leaves the factory?!)
- -- finish that seems to scratch up very handily
- -- filter threads are not quite today's 40.5mm size.

Careful handling can overcome these problems, but they are all things to
look for in buying a new one.

The Canon version of the Sonnar has a brass barrel and click stops (to
f/16, not f/22 like the Jupiter), suffers from a similar fragility of
its coatings, and sometimes is seen with blistered chrome.  The extra
sharpness, I think, justifies its price, which is now around $250.  This
is in part because the Jupiter-3 is getting (relatively) expensive,
hitting $150 and up on some popular auction sites.


"Stanislaw B.A. Stawowy" wrote:

> Hello!
>
> Thank you for these tests. Indeed, Russian
> lenses have very pleasant unsharphess (contradiction?)
>
> Jupiter 3 have many aperture blades, this may make
> good out-of-focus-lights reproduction (bokeh?
> Does anyone believe in bokeh? ), also design is
> somewhat symmetrical - look at drawing of Sonnar 1.5/50,
> this may help to make this design considerably rectilinear.
> One more - Jupiter have only six air-to-glass surfaces.
> If we add also that all surfaces are coated or multicoated
> (true? Marc, help please..), we have a design which has
> remarkable contrast and is resistant to flare. Even if
> flare appears, this is only one-two spot, even pleasant.
> Bad point of this design is single, strongly curved front
> element, making Jupiter 3 prone to astigmatism. I haven't
> tested Juipiter 3 for this, but, judging by my photos
> ( www.geocities.com/Stanislaw_Stawowy - I promise to add
> more photos as fast as I will have some time - now I am
> too much absorbed by working with Alastair on FOM2 website),
> astignatism is minimal.
>
> Please, whoever have something to add, write this.
> I am currently looking for people' opinion about Russian
> lenses and will finally put some compilation of this
> on my website (of course asking for rights to publish first :-)
>
>                                             St6.
>
>                                 St.
>                      (Stanislaw B.A. Stawowy)

Replies: Reply from "Dan Post" <dpost@triad.rr.com> (Re: [Leica] Jupiter lens 'tests')
In reply to: Message from "Stanislaw B.A. Stawowy" <watteau@krakow.neurosoft.net> (Re: [Leica] Jupiter lens 'tests')