Is this fungus inside my Focotar 40mm enlarging lens?

logan2z · Saturday at 2:57 PM

I haven't used the lens for several years and just pulled it out today to find this:

I live in a dry climate (San Francisco Bay Area, away from the coast) so I'm surprised to see what appears to be fungus inside the lens.

Could it possibly be something else?

BMbikerider · Saturday at 3:17 PM

It could be but.....Fungus can take a few forms. One looks like a demented spiders web or forked lightening flashes, usually from the edges but it can appear almost anywhere. Another version is a general misting of the lens with swirling or streaking marks like a badly cleaned lens using a slightly greasy cloth. These look like dust particles, but to be sure only a strip down by a lens technician will tell accurately. Anecdotal chit chat usually gives all descriptions of possibilities (including mine) I am sure there are manifestations around I have never come across.

Oddly the subject of fungus inside my Nikon 35/70 AFD lens (the swirling type of fungus) knocks the contrast right off if I am using it on my D800, but used with colour or B&W film on my F2a there is little or no difference to results from a spotless lens.

Don_ih · Saturday at 3:23 PM

Looks more like paint flecks.

logan2z · Saturday at 6:15 PM

Don_ih said:
Looks more like paint flecks.

Hmm, you might be right. I wonder if some of the black paint from inside the lens has flaked off.

MattKing · Saturday at 6:18 PM

logan2z said:
Hmm, you might be right. I wonder if some of the black paint from inside the lens has flaked off.

aka Schneideritis?
https://www.photrio.com/forum/threads/what-is-schneideritis.18363/

Don_ih · 2025-08-24T05:12:41-0400

logan2z said:
Hmm, you might be right. I wonder if some of the black paint from inside the lens has flaked off.

It's usually pretty simple to get an enlarging lens apart to see what's inside. For now, though, there's a chance that those little specks won't make any difference in use.

Sirius Glass · 2025-08-24T13:39:26-0400

I think it is lens debris. If it does not affect printing, leave it as it is. Otherwise fix it yourself or send it to be repaired.

logan2z · 2025-08-24T16:02:12-0400

Sirius Glass said:
I think it is lens debris. If it does not affect printing, leave it as it is. Otherwise fix it yourself or send it to be repaired.

I can see the effects of the debris when printing.

I was planning to sell the lens since I no longer use it (or the Leica v35 enlarger I bought it for), but I’ll have it repaired before doing so.

Don_ih · 2025-08-24T19:29:00-0400

logan2z said:
I was planning to sell the lens since I no longer use it (or the Leica v35 enlarger I bought it for), but I’ll have it repaired before doing so.

I doubt you can sell it for enough to recover the cost of getting it fixed.

logan2z · 2025-08-24T20:35:54-0400

Don_ih said:
I doubt you can sell it for enough to recover the cost of getting it fixed.

I got an estimate to have it fixed and it's actually not too bad. I'll get it fixed and then decide what to do with it. I may just hang onto it in case I ever put the v35 back into use again.

BMbikerider · 2025-08-25T04:49:21-0400

logan2z said:
I can see the effects of the debris when printing.

It may be some other problem because the specs of whatever they are will be so far out of focus when printing, to be of any significance. The contrast may be down a little, but the defined specs themselves will not be visible

koraks · 2025-08-25T04:53:20-0400

MattKing said:
aka Schneideritis?
https://www.photrio.com/forum/threads/what-is-schneideritis.18363/

In my experience, Schneideritis generally does not involve bits of paint actually coming loose and starting to bounce around between lens groups. It's really limited to basically air bubbles between lens elements and the barrel.

logan2z said:
I can see the effects of the debris when printing.

At small apertures I can see how these might show up. I'd also expect that disassembling the lens and cleaning out the stuff takes less than half an hour. It's the kind of job I'd personally do myself.

Is this fungus inside my Focotar 40mm enlarging lens?

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Is this fungus inside my Focotar 40mm enlarging lens?

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