Minolta M-Rokkor 40mm Fungus: Common Issue?

[TommyPlouffe]

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It came to my attention that there seems to be a fair amount of 40mm f2 M-Rokkor lenses that have fungus. (I know that the same goes for their 28mm & 90mm M-Mount lenses.)

Is this constant from beginning to end of the production of the two versions of this lens, or is it specific to some production batches?

Thanks.

Edited July 17, 2019 by TommyPlouffe

[g2van]

Fungus is not rare for older lenses. Perhaps it affects Minolta more because of the high humidity in Japan. More common is white spots. 

My copy is perfectly fine. There are a lot of good copies around, just be careful when buying. Use the flashlight test to be sure. The first copy I bought was very nice outside but there was the problem of white spots and had to be returned. 

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[lct]

Never heard of white spots in any of the two versions of the M-Rokkor 40/2, only in the M-Rokkor 28/2.8 so far but none of those lenses are especially prone to fungus and neither is the M-Rokkor 90/4 in my book. It's just that those lenses can come from Japan or other high humidity countries as suggested by g2van above. +1 about the flashlight test.

[Alberti]

I have the very hazy 28mm. I accept it. It is picturesque; like in churches. It looks as if a Hasselblad with a Schneider lens is used. (And it has that mid-frame quality too when there is no back- light).

However - two years ago, in the M-Rokkor 40mm I got white haze spots on the inside of the back lens element too. In this lens it is not acceptable. I have so many very good pictures in all circumstances. Even with the sun in the frame. It's so good wide open even into the edges, it beats many other lenses. The problems might come because I always put this -remember it is small - lens in my trouser pocket. That is a place where it can get humid  . .

But maybe it got jealous because I bought a 35mm Summicron V4

I should send it off for CLA quickly (>Will Van Maanen) , because I think the spots are increasing. In pictures I can now see a halo on white areas.

I'll add a picture. (24mm in macro mode .. 🙂

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more vague:

Edited April 20, 2022 by Alberti

[grahamc]

If it can give anyone confidence I have 2x 40mm Rokkors and no fungus issues with either .

I have the 28:2.8 which I specifically bought due to no white spots. i believe the famous white spots on this lens to be something other than fungus (probably explained more in earlier replies on this thread..sorry I'm busy right now to read in detail) .  According to my research if certain of these famous lenses were sent back to Minolta then they were fixed and the white spots won't return. Equally if a copy doesn't have it yet after these 40 years then 'shouldn't' get it. I'm not sure which one of these applies to mine but it is fine and you can find them (at a premium) if you are patient . 

When I bought my second copy of the 40:2 (amazing lens and cheap local purchase so impossible to ignore) the seller had a 'spotted' version of the 28 they threw in for free very generously and yes it isn't pretty.  I am yet to test it for images but will probably take the mount off and mount it to one of the 40s.  This is because the 28mm brings up 35mm frame lines on Leica M, but the 40mm will bring up 50mm framelines.

So when I use the mount from the 28mm I will have one 40:2 for my Minolta CLE (original mount and activating 40mm CLE framelines) and one for Leica M (mount from 28 activating 35mm Leica M framelines). 

(There is another way to activate 35 framelines on an M which is to file off a small part of the 40:2 Rokkor mount - instructions on internet if you search for it).

Sorry for writing so much but I love this lens would recommend it to anyone and would possibly be my only lens if I had to choose 
 

 

Edited April 20, 2022 by grahamc

[grahamc]

3 hours ago, Alberti said:

I have the very hazy 28mm. I accept it. It is picturesque; like in churches. It looks as if a Hasselblad with a Schneider lens is used. (And it has that mid-frame quality too when there is no back- light).

However - two years ago, in the M-Rokkor 40mm I got white haze spots on the inside of the back lens element too. In this lens it is not acceptable. I have so many very good pictures in all circumstances. Even with the sun in the frame. It's so good wide open even into the edges, it beats many other lenses. The problems might come because I always put this -remember it is small - lens in my trouser pocket. That is a place where it can get humid  . .

But maybe it got jealous because I bought a 35mm Summicron V4

I should send it off for CLA quickly (>Will Van Maanen) , because I think the spots are increasing. In pictures I can now see a halo on white areas.

I'll add a picture. (24mm in macro mode .. 🙂

 

more vague:

 

Sorry to hear about the 40 Alberti ! 

[lct]

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Indeed fungus may appear on the glass itself whereas schneideritis may apppear on black paint used to reduce internal reflections in the lens. Fungus can be a problem on any lens. Schneideritis can be a problem on the Rokkor 28/2.8, not 40/2.

Edited April 20, 2022 by lct