Jupiter-21A, a nice gem

Time for some more vintage Russian lenses. The Jupiter-21A from KMZ, a quite rare 200/4 Sonnar design as opposed to the common Jupter 21M version.

Some time ago I acquired a very cheap Jupiter-21M with a tiny bubble in the massive front glass and broken A/M switch. Nothing that affected the IQ at all, but when a Jupiter 21A surfaced for peanuts, I grabbed it and sold the 21M. Why?
The 21M is a quite large and heavy lens. It is nevertheless very beautiful, with perfect proportions and lovely IQ, very sharp and silky smooth OOF rendering with almost gaussian bokeh highlights. The 21A came out in 1968 and the 21M in 1973, but they share the same optical design and the older one is fitted into a smaller and lighter body that also incorporates the preferred pre set aperture operation.

Here you have them side by side before I parted with one of them:

Jupiter-21A and Jupiter 21M

The 21M weighs in at 1 kg and the 21A at 750g. Both has built in retractable lens hoods and are most common with M42 mount. The common 21M version can easily be had in mint condition for less than 40 Euros on the bay and must be one of the absolutely best price/performance vintage bargains one can make. It is still in production and sells as new for 100 Euros or so. As earlier stated, the IQ is very good and it has very good control over CA or PF as compared to the competitors from the same era (Carl Zeiss Jena, Pentacon, Asahi Pentax, etc). The Jupiter is a good alternative to the legendary Carl Zeiss Jena Sonnar 180/2.8 or 200/2.8 due to IQ, weight, MFD, cost and less mechanical iris breakdowns, it is of course slower at wide open though.

Warning: Although multi coated and equipped with a sun hood, the jupiter is not very good against the light in some angles. Especially not the 21M version. This is due to internal reflections inside the lens barrel.

Tweak: The 21M has a large flat piece of metal close to the mount that can reflect light straight onto the sensor, which washes out all contrast in the image. It can be painted matte black, or glue some black velour fabric onto it to improve the performance.

Now some images, as usual wide open or thereabout. First out is a portrait of a dog named Ketchup.

Jupiter-21A, Ketchup.

Then we take a look at the clock.

Jupiter-21A, what time is it?

Beautiful greens and bokeh.

This lens is quite handy for walk around photography when a little bit more reach is wanted.

Jupiter-21A, pavement

Now let's check out the distance capability.

Jupiter-21A with stacked TCs, critically sharp moon shot.

The lens is also critically sharp at infinity. Although used with stacked low budget TCs (tele converters) the dimples of the moon has very good definition, even viewed in original resolution. I have tried to do this again some times. I'm very thorough with using a stable tripod, mirror lock up and remote trigger, but is never seem to get this good again. Perhaps the atmospheric disturbances were very low that lucky night.