[Helios 44-2] Is this fungus?

Fandyus · Joined: 12 Apr 2020 Posts: 108 Location: Czechia

A family friend just gifted me an old Zenit that I think his father used to own. The camera's shutter is stuck but the lens was near mint, I already tested it and it is perfectly centered and only shows some mild cosmetic signs of wear. The serial number is 81351584. There are however, some weird fibers inside.

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Anyone know if this is fungus? Thanks.

calvin83 · Joined: 12 Apr 2009 Posts: 7574 Location: Hong Kong

I think so.

Zamo · Joined: 08 Feb 2019 Posts: 168

Looks like it. And it is very easy to disassemble and clean, if you dare doing that.

Fandyus · Joined: 12 Apr 2020 Posts: 108 Location: Czechia

Fandyus · Joined: 12 Apr 2020 Posts: 108 Location: Czechia

Dejan · Joined: 05 Jan 2021 Posts: 149 Location: Belgrade, Serbia

I've been cleaning Helios 44-2 lenses a few times and I've never encountered issues with the centering. The lens' construction is so simple that it's very easy to put the elements back in place. As long as you make sure the glass is in its proper place (and nothing is reversed) I've no doubt that everything will be OK. There aren't many parts inside so it should be easy to remember what goes where (and there are many fine tutorials to help). As for the chemicals, I'd start with the least aggressive one (sometimes even something like Fairy can be enough) and see what happens. I'd also wipe the inside of the lens with alcohol to prevent the fungus from coming back.

Lloydy · Expire: 2022-01-01

It's a simple and robust lens. Fungus like that is usually easy to clean, I've used cold cream - the stuff people use to remove make up - with success. It has no strong solvents or chemicals and seems to dissolve the fungus. Just paste it on, let it soak for 15 minutes or so, and wash it off with dish soap and water.

Zamo · Joined: 08 Feb 2019 Posts: 168

Looks thin and probably comes out easily. I have used commercial (not too concentrated, that is) hydrogen peroxide and the fungus dissolves in 1-2 minutes. And, as said, you cannot decenter the glasses, they have their location where they fit tightly.

cbass · Joined: 27 Jul 2019 Posts: 450

So for those knowledgeable on the subject I have some questions.

So how do lenses get decentered? Is it largely a product of the manufacturing process and thus usually you can't correct it?

Also, what is the purpose of a collimator?

I have read the following on another forum:

visualopsins · Expire: 2025-04-11

https://garyseronik.com/a-beginners-guide-to-collimation/

Mechanical construction, how elements are held in position, determines if decolimination can occur -- most modern lenses have precision-ground edges and mounts which prevent misalignment

Glued elements separated, on regluing can become decentered.

Aspheric elements are no different from non-aspheric; the radial differences do not cause decentering as those are along another axis.

Inaccuracies in curvature of elements require radial alignment to achieve colimination.

cbass · Joined: 27 Jul 2019 Posts: 450

It looks like even on a Helios lens collimation can make a difference and there is some room for optical alignment.

This guy took what he knew to be a factory assembled Helios from 724 lp/mm to 769 lp/mm but he spent some time and had special equipment. Later in the thread he tries to do better aligning a MIR 35mm than the factory, but after 3 hours falls short.