Opening and cleaning AF 50mm f1.7

Greetings to everyone,

For a long of period of time I wanted to buy myself a film camera. Before I was looking in the wrong places and at the wrong cameras which were really really expensive (read Leica cameras) so I thought this is not for me.

In the begining of this year I decided to go deep dive again in my research and Minolta stood out, I really liked what they did before. And fast forward, here I am, with Minolta 7000i, 7xi, Sony A300, couple of lenses, more on the way, so you can guess, gear accusition syndrome got me too.

Anyway, I found this 50mm f1.7 for a nice price on ebay, about 20USD, everything looked fine, no fungus, dust, scratches, anything. So I order it and got it last week and it came in this state (I'll poste the picture).

So my question is, what happened here, is this fungus? Is it cleanable? When looking from the front side you can see all of that, but looking from the rear, not so much. I saw one video on YT where on guy opens similar 50mm f1.4. But on that video I saw that front element glass are kind glued? And I think this may be just between those two glasses.

Anyway, it does not affect images at all, but it's really hard for me to look at this, and tempted to open it. What are your suggestions? Is there possibility to open that two front glasses? Anyone done something similar before?



Thanks in advance.

Welcome to Dyxum. You will find a guide to repairing a Minolta 50mm lens
here

I can't tell from the pictures if it in the coating or if it is separation between the elements. You will find out when you take it apart. It's a good lens to practice repairs on.

It doesn't look like fungus, so hydrogen peroxide may be to hash and not the most appropriate treatment. It could be marks from solvent or some oily or greasy stuff, difficult to judge by pictures. Heptane (typically used for cleaning stained clothes or remove adhesives) are most efficient for cleaning grease residues, but dish soap and alcohol may also work.

If the "stained" coating is inside a sealed lens group (see the last two images at the pganzel page in the link you got), I would not try to fix it. It may not have any substantial effect on images (as you said).

I don't think storing and shipping is the main cause of these spots, I guess there was some contamination prior to that, but it look like it has spread (high temperature??).

Fungus is a common problem in old lenses from Japan, but most Japanese sellers states the condition very honestly.