Archived posting to the Leica Users Group, 2000/10/16
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]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)