Super Yashinon 135mm issue

A few things to update... After opening the front block for cleaning, the question about elements/group is now half answered, and a bit of deception is discovered at the same time.

There are 2 spanner slots in the name ring, and that's where I inserted the 2 extended straight bits from the spanner to twist loose the front block as one piece. I got lucky that it happened the way I assumed it would, but in fact, that name ring has a very real purpose for holding in the single front element. To remove the entire block as one assembly, it does indeed work like the modern ML's... Turn the whole front section CCW, and everything comes out after about 10 turns. If the front element needs to be removed, it makes far more sense to remove the rear elements from the whole block, and then use the spanner on the front ring if further tear-down is required. I wasn't particularly worried about removing the front glass just to give it a light cleaning, so I left it in place.

The cemented group from the front block...


On the quandary of whether anything might be cemented in the front block... the answer is yes. The photo shows the 2nd and 3rd elements are cemented, with a rather thin convex element for #2. There's a clear line visible where they meet, and given that the lens was made long before UV cured cements were ever used, the tree sap balsam of this lens is the home to all the bubbly bits from the earlier shot. What looked like a thin solid field of fungus turned out to be a layer of haze that had a tentacle-blobbed edge on it, but was fairly easy to remove once everything was opened.

I don't have anything I can use for re-heating the cemented group to fix the bubbles, and this isn't a rare enough lens to warrant the cost of having it done. It doesn't seem like it's anywhere near the focus point at any distance I've tried so far, so although they look very odd, the bubbles will stay. I have no way of knowing if they've always been present, or if they've grown over time, but for now they don't seem to be an issue. I still don't know the makeup of the rear block, so investigating the elements/groups on the back side may have to wait for another day when I have some time to peek-n-poke around and get an idea on how the back half of the lens is assembled.

This is only one test sample, and it has had post work done (as have all the rest in the testbed gallery), but most are shot wide open, with a tad bit of softness on pixel peeping, but CA isn't bad and no distortion to speak of. Colors are overly saturated and contrast can be a bit much in the raw files, but color is pretty accurate. Resolution edge-to-edge looks as good as anything I've seen for a lens this old, and better than a few of the newer/modern versions. I intentionally left the hood off to see what it would show without one, and I'll try some new shots (and better composed, on better lit subjects) with the hood in place, now that everything is cleaned.



I still haven't shot the 'rear lens cap' yet, so that's next on the agenda.