FAQ FAQ  Forum Search   Events   Register Register  Login Login

Opening and cleaning AF 50mm f1.7

Author
Spaha View Drop Down
Newbie
Newbie

Joined: 19 April 2023
Country: Bosnia Hercegovina
Status: Offline
Posts: 3
Post Options Post Options   Quote Spaha Quote  Post ReplyReply Direct Link To This Post Topic: Opening and cleaning AF 50mm f1.7
    Posted: 19 April 2023 at 14:39
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.
 



Back to Top
QuietOC View Drop Down
Senior Member
Senior Member

Joined: 28 February 2015
Country: United States
Location: Michigan
Status: Offline
Posts: 3681
Post Options Post Options   Quote QuietOC Quote  Post ReplyReply Direct Link To This Post Posted: 19 April 2023 at 15:05
I would try cleaning the outside first. That looks like fluid contamination--maybe with a solvent?

How much do you time do you want to spend on a $20 lens?

I have taken one of these somewhat apart before, but I don't remember much about it. I have two of the later versions right now. The internal construction is quite a bit different on that version.
Sony A7RIV LA-EA5
Pentax Q7 5-15 15-45/2.8 8.5/1.9 11.5/9
Back to Top
Basil View Drop Down
Senior Member
Senior Member

Joined: 03 December 2009
Country: United States
Location: Minnesota
Status: Offline
Posts: 2745
Post Options Post Options   Quote Basil Quote  Post ReplyReply Direct Link To This Post Posted: 19 April 2023 at 15:06
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.
To see is to enjoy. To see beyond is to rejoice.

A77Mark II; A6600; A99; various film bodies and an ever-changing collection of lenses
Back to Top
Spaha View Drop Down
Newbie
Newbie

Joined: 19 April 2023
Country: Bosnia Hercegovina
Status: Offline
Posts: 3
Post Options Post Options   Quote Spaha Quote  Post ReplyReply Direct Link To This Post Posted: 19 April 2023 at 16:08
I havent tried to clean it outside yet, I am extra careful with the lenses. At least trying to be.

This line could be the coating, it's difficult to tell wether it's outside or inside the glass.

Timing is not a problem to me. If I could fix it, good, if not, I'll buy another one.

Other spots are inside the lens and I think these could be easily removed, but when looking from the rear, they appear somehow as a drop of water or oil.

I will try to open lens and will use hydrogen peroxide.

Now I forgot to tell, I bought this lens from USA and used dropshipping service. The lens has been at least 3 weeks in the warehouse, and plus week more until I got it at my adress.

Could that create problems like these? I just got today 50mm micro lens directly from Japan, and it's almost in mint condition. If this could be a problem, so I would just try to buy lenses where seller can ship directly to my address.

Here are the more picture I tried to take of the lense.





Basil thanks for the link, it'll be helpful a lot.

Back to Top
amrep View Drop Down
Senior Member
Senior Member

Joined: 02 February 2015
Country: Norway
Status: Offline
Posts: 316
Post Options Post Options   Quote amrep Quote  Post ReplyReply Direct Link To This Post Posted: 19 April 2023 at 17:32
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.
Back to Top
Spaha View Drop Down
Newbie
Newbie

Joined: 19 April 2023
Country: Bosnia Hercegovina
Status: Offline
Posts: 3
Post Options Post Options   Quote Spaha Quote  Post ReplyReply Direct Link To This Post Posted: 19 April 2023 at 18:00
I saw some videos on cleaning fungus and most of them used hydrogen peroxide. I may try then with isopropyl alcohol then.

Looking at the pictures, it looks prety much difficult to open it.

I just don't want it to spread further. That's all.


About the lens, I kinda suspect that the seller have switched lenses, because what I saw on the pictures was pretty much clear lense, and now it's totaly opposite as you can see.

Anyway, thanks for the reply muchachos. Helped a lot. Will keep you updated later once I got time and tools to open it.
 



Back to Top
Dyxum main page >  Forum Home > Equipment forums > Lens Talk > A-mount lenses

Forum Jump Forum Permissions View Drop Down



This page was generated in 0.047 seconds.

Monitor calibration strip

Dyxum.com - Home of the alpha system photographer

In memory of Cameron Hill - brettania

Feel free to contact us if needed.