Originally posted by nikuyakun
Thanks for the advice guys.
I recently tried to clean a Penatx SMC A 50mm 1.7 lens and it was a disaster.
I am too impatient and mechanically inept to attemt another repair job on any lens.
Far too many small screws and tiny springs.
Bear in mind that a Takumar does not have auto aperture on an A-lens, so the complicated springs and things will not be present. As long as the diaphragm is working well, you will probably have little to do with any of the mechanical bits.
I took apart a very old Super-Tak 28/3.5 to clean the fungus and it was not too difficult once I got the name plate to move. Actually that was the main problem. The lens was pristine and older than my 46 years (I am far from pristine...) and the name plate was a real pain to move. After I got it to move I could get most of the lens elements out to clean.
A couple of tips.
- Get the right tools. If you improvise then you are bound to scratch something.
- Take photos as you proceed. It makes it easier when you reassemble the lens.
- Decide a protocol of which way up a lens element is and stick to it. Place the elements on a clean surface (lens cloths) as you remove them, in order and the right way up. Some elements look symmetrical, but are you really sure?
- If an element has black paint on its edges be careful not to scratch it off. A Sharpie can be used for a reasonable repair for a scratch, but it is not as good as the matt black paint you've scratched off.
- Do the disassembly in a 'box', ie something with edges so that small screws that fall out don't end up on the floor and lost.
- Do it in a place with lots of light and if you are anywhere near my age, get a desk light with a magnifying glass.
- If you get near disassembly anything with a dente do the disassembly in a plastic bag, or better, don't do it at all. Too many times I have heard a ball bearing ping across the room and I have spent literally hours on my hands and knees scanning the floor with a magnet looking for the tiny ball and spring. (You find *lots* of old staples that way!)
Finally (and don't shout at me for saying this) although both lenses are very good, they are also rather cheap. It may be better just to buy them used and fungus-free off someone else. But with that in mind, perhaps you may be persuaded to learn the art of lens cleaning with the knowledge that it won't matter too much if you fail to re-assemble the lens.
Richard