How easy is it to remove fungus?

Hi guys,

Is it an easy job to take a (manual) lens apart, clean it and then re-build it? Is it just a case of having a few jewellers screw drivers, or is there more to it than that?

(PS. Still waiting for my K20d from Warehouse Express)

Thanks, James

In addition to the screwdrivers (and use good quality ones, not the cheapo ones you get in general purpose tool kits) you'll probably - depending on the lens in question - need some sort of ring wrench. You can sometimes improvise with things like rubber bungs from the ends of walking sticks etc.

As for removing fungus, there are some good tips here on different methods to try, although if it's etched into the glass itself then there's probably little you can do.

Good luck!

Thanks, thinking of getting a second hand lens off ebay with some fungas in it just to "give it a go" removing it!

Does anyone know if fungus grows on the metal insides as well as on the glass? Just trying to get my head around which bits may need cleaning. I like a challenge, and may give this a go. I have access to hydrogen peroxide where I work, so that is helpful

Fungus can grow anywhere inside the lens. What you should not do is keep an affected lens with any others. Fungus propagates using microscopic spores and when conditions are right, they flourish and can easily spread to other equipment. When they grow on the glass, their excretions can corrode the coatings to a point that affects the image.

If you don't know what you are doing, I'd leave well alone.

Sometimes these fungal spores can be between two lenses that are part of a group. If that group is glued together, and they often are, the lens is bin fodder. Even if you get the group apart, it's not likely you'll have the equipment to put it back together again.

I partially dismantled a SMCP-A 50mm lens once to repair a stuck aperture ring. Nothing like as complicated as that which you are contemplating. Believe me when I say it's not a procedure I intend to repeat. I did fix it, but it was a nightmare.

Leave lens cleaning to the experts. If they fail, it's probably for a good reason. You will probably fail due to lack of knowledge and/or tools and you'd have ruined a potentially recoverable lens.

I have to say that I fundamentally disagree with this statement - sorry!

Nobody knows what they're doing the first time they try something - we all make mistakes and we learn from them, for many (like me) that's actually the fun part!

If you can bag an old lens off eBay for a couple of quid then there's really nothing to lose - if you can fix it then you've got a lens for a bargain price, if you can't then the small amount you've paid in cash can be offset against the lesson you learn (hey, education costs! ).

If the lens in question was something of high value like an FA*200 Macro then I'd agree that the cleaning would be best left to experts, but if it's something like an old Helios 44M (for example) I'd say go for it - you never know unless you try!

I do concur that the fungus could be anywhere, although from experience (I've bought a lot of fungus ridden lenses at knock-down prices over the years) it's usually on the edge of a glass element. If it's got between a cemented pair of elements then I'd say forget it - trying to seperate them to get at the fungus will be nigh on impossible. I've been lucky in so far that I've more often had lenses where the fungus has been on a single element and therefore relatively easy to get at. Your mileage may vary...

A couple of tips:

While you disassemble the lens you'll probably find it helpful to take photos as you go along - referring back to them is a great way of not ending up with "spare parts" when you've put it all back together again.

Also, work over a smooth surface with a big lip (I use a cake tin) because small parts have a habit of appearing and disappearing as you move along. Most lenses will contain at least one tiny ball bearing (for the aperture ring click stops) which I guarantee will make a bid for freedom by heading for the nearest carpeted area - never to be seen again.

Good luck anyway!

I agree with Hefty, if the lens is worth peanuts then you have nothing to loose and a lot to gain.

I would add though that not all lenses are created equal. Pentax and other Japanese lens makers tend to build complex lenses with many interlocking tiny pieces, not really intended to be taken apart and put back together again.

East German and Russian designs tend to be simpler and built more with the idea in mind that they may need to be taken apart, fixed and re-assembled.

I took the aperture off my Zeiss Jena Flektogon, cleaned it up and put the lens back together with relative ease. I looked into doing the same for an old Takumar 135 which has the same problem and concluded that I didn't stand an earthly.

So if you're going to buy a lens as a project, maybe a Russian or East German one would be a good place to start.

Ahhhhhhh, that explains a LOT

You are not alone I promise you! I'm a regular customer here.

You can usually get away with packets in 1mm and 1.5mm sizes, I've yet to come across a lens that doesn't use either one or the other.

I can't remember who, but someone on the forum put me onto Simply Bearings here in the UK http://tinyurl.com/6orgs8. I can recommend them.

While on the the subject of lens repair, does anyone have a source for replacement the so called 'Jesus' springs(the small springs that can be found behind the lens contact points)?

Steve

what size are they? (having never had the guts to try dismantling a lens with electrical contacts, I've not seen one!)

Can't remember the exact size, I have it noted somewhere. From memory approx 5mm long, 2mm diameter. They sit behind the contacts on the lens mount, are easily damaged and much easier to lose then the indent balls.

Steve

You could try smallparts.com or alternatively give your local locksmith a ring - those tiny springs are their bread and butter.