Fungus

[GRHazelton]

I posted this in the Bronica group with so far no response, so I'll try a broader audience

I just scored a plain prism finder for my Bronica S2a.

But ... While the exterior cosmetics are excellent, there is apparent fungus and some dirt inside the finder. I am torn between returning it or, given the difficulty of finding the prism, keeping it. Would the sunshine treatment I've seen suggested for lenses be of help? How difficult is it to disassemble (and reassemble) the unit?

The possible fungus is out of focus in viewing, so it may be on a surface of the prism.

 

[Fixcinater]

The sunshine would only halt growth, not eliminate the obstruction.

 

[tony lockerbie]

As the fixinater says, the sunshine will just stop the fungus, which is no bad thing. Most likely it has already etched the glass or coating so cleaning will only reduce it somewhat. I would be just inclined to give it a good dose of UV and then learn to live with it as it won't affect your images.

 

[Sirius Glass]

If I was you, I would return the camera and have it exchanged for another. Let the seller deal with the remediation. You bought the camera to use and to enjoy it, not to start a new career dealing with a problem that is not of your making.

 

[Poisson Du Jour]

Dismantle the prism and treat it the way Zeiss deals with fungus. I used their method to go hammer and tongs at fungus inside my ancient Pentax 67 right-angle finder. All I have now is faint etching on the prism block and an internal lens element where the fungus once was.

http://www.zeiss.co.za/camera-lenses/en_za/website/service/fungus_on_lenses.html

 

[John Koehrer]

Because it's hard to find, I'd clean it.
The good thing is Prisms like this are easy to take apart. Do your best not to have extra parts
when you're done.

The Zeiss instructions are pretty much what I've done with fungus infested glass in the past
and only once have I seen etched glass. Like they say though, dry storage is the best preventative.