I received the Tomioka Yashinon today and have been giving it a run through.
Of interest - unlike other Tomiokas it seems, the Yashinon is an 8-blader, like the Porst. Its also unique to some others by virtue of a factory sliced rear element, shaped like a 5/6 full moon. This is to make room for an auto aperture pin on a camera body not designed to house that large of a rear element by the looks of things.
Also, while the aperture ring is marked 1.2, 1.4, 2, 2.8, 4... there are actually unmarked incremental stop all the way through to 16, so one can dial in 1.7, 2.4, 3.5... (presumably) if desired. The Porst on the other hand has no half stops and goes straight from 1.2 to 2. This Yashinon, like the Porst, uses a 55m filter thread, where the later Tomiokas use a 58.
Leaves me to wonder if the optics were the same across all models of Tomioka 55s over time.
With all these 50's here, curiousity starts to take hold. I had a mini shoot-out between the Porst 55, Yashinon 55, Voigt 58 and Super-Tak 50, just for the heck of it. I shot a tennis ball with each lens at wide open, f2 and f4 using minimum focus distances.
My notes:
- it was possible to note the 1.2s had shallower depth of field and more diffusion of contrast (and thus lower contrast) while wide open. The 1.2s and VL to a certain extent appeared to render a soft focus sort of effect at this aperture, with both 1.2's, its as though there was no distinct point of focus, just a mild graduation from more
oof to less. That is not to say details are not visible, just that they appear diffused.
- the VL58 can focus as closely as the Tak (.45m) while being 8mm longer. This sets the Nokton apart from the pack in several ways. a) Its has a higher magnification factor than the others (1:5.75, not sure of the rest but over 6 for sure) b) It appeared to render
oof as dramatically as the 1.2s at minimum focus distances with this closer focus ability, and with a similar amont of diffusion as well. c) VLs
DoF was narrowed vs the Tak at 1.4 under these conditions - correspondingly, it was tricker to hit focus correctly, also similar to the 1.2s.
- The 55's at .6m (ish) and Tak at .45m all had apparenty identical maginification given thier focal lengths.
- The Voigtlander and Tak were sharpest wide open. Even with more diffusion at its closer focus range at 1.4, the VL was offering a clear focus point unlike the 1.2s, though the Tak appeared sharper over a wider depth. As a result, the Tak also appeared less dramatic than the rest
oof-wise, wide open and was well contrasted and detailed at 1.4. Depending on your intended use, the Tak might be best of the four for certain applications where a gentle diffusion of detail at 1.4 was not called for. It would seem to be a good choice for 3D type shots where the point of focus is clearly defined against the background.
- At all stops, it would be splitting hairs to call the Porst or Yashinon sharper. They render virtually identically in all but
oof areas it seems. It was my sense that the Porst is more sensitive to making light rings in its bokeh, where the Yashinon is perhaps less animated in this way, appearing more gentle/soft in
oof. More testing will be done.
- At f4, everybody had a respectably sharp rendition. Surprisingly, the Nokton had the most apparent bokeh at f4 among the bunch. Again, being closer to the object would affect this, but it was interesting to see. It was also the sharpest, but there's not much in it by this aperture.
- Mecahnically, there are some clear differences to note. The Voigtlander, and indeed all the modern Cosina lenses I have, have done away with something all the old lenses have over their skins - grub screws that keep the correct tension on parts, holding them in place. This 'cleaning up' is a welcome development. The modern lenses feel more refined and well thought out, less left to chance and more robust. Nothing rattles or creaks, etc.
Overall, I was a bit surprised. The 1.2s are pretty decent, the Tak showed a useful character differing from the rest and the VL had tricks up its sleeve. For all the times in the past I'd passed on one of these older 1.2s because of their reputations as soft performers, they've turned out to be pretty decent performance wise after 1.2. Yet, its because of their characteristic rendering at 1.2 that I've finally bought them as a bokeh brush.
It seems at least in a close focus test, you should choose your wide aperture lens based on what its doing for you personally at wide aperture, because once they're stopped down, the lines between all these 50's blurs... err, sharpens to where it would take a computer measuring pixels to tell the difference.
