QuestionBoot sale Super Takumar 35mm... with a cobweb inside. Hopeless?

Picked up a Super Takumar 35mm f/3.5 at the Sunday boot sale up on the racecourse for £8 this morning (the chap wanted a tenner, but I had a bacon roll in one hand and I think he took pity on me). Held it up to the light in the car park and there's what looks like a little cobweb, sort of feathery, in among the middle elements.

My dad always said fungus was the end of a lens, but my dad also said decimal currency would never catch on... so what do I know? Is this salvageable at home with a spanner wrench and some patience, or is it a send-away job, or is it a paperweight now? And will it spread to my 50 1.4 if they share a bag? It'll go on the Spotmatic either way, assuming it lives. Do lenses have feelings? Asking for a friend.

Feathery and in the middle is fungus, almost certainly. On an £8 lens... honestly, if it hasn't etched the coatings it'll come off. Takumars are about the friendliest lenses ever made to take apart, the front group usually unscrews with a rubber jar opener before you even need the spanner. Diluted hydrogen peroxide with a drop of ammonia on a cotton bud, wipe from the centre out, then a proper lens cleaner after.

If it has etched, you'll get a lens with a touch less contrast into the light that still takes perfectly good pictures. On HP5 you'll never see it. My own 50 1.4 came with a faint etch mark on the rear element from a previous owner, and I've printed from it at 10x8 a dozen times and nobody's ever spotted it, including me, and I know where it is.

Keep it away from the 50 until it's sorted, and chuck some silica gel sachets in the bag either way. Damp bags and cupboards are how it started in the first place. Don't go wiping it with anything off the kitchen shelf before you've got the right stuff, mind... that's how people turn a cleanable lens into a scratched one. Just saying

Pal, it's an eight quid lens. Have a go yourself. Worst case you learn how a Takumar comes apart, which is worth more than £8 of anybody's money. I took apart my first lens at about fifteen with a butter knife and a lot of swearing. It never worked again. The second one did. That's how you learn, pal, nobody's born knowing which way the retaining ring goes

Or bin it and buy one without fungus for £30. Life's short, Pete.

mfrost said:

Or bin it

I'm afraid I couldn't possibly... it's been looking at me from the kitchen table all morning. Spanner wrench ordered. If I end up with a pile of tiny screws and regret, you'll be the first to know

Once it's clean, leave it in a sunny window with both caps off for a few days. UV kills what's left, or at least stops it. Old trick, works. We used to do it with Nikkors in the 80s, there was a fellow at the camera club who swore by a week on the dashboard of his Buick. Wouldn't recommend the Buick part.

Report from the kitchen table: front group came apart with the jar opener as promised, fungus came off with the peroxide, and there's a faint mark left on one surface if you shine a torch through it. Ran a roll of HP5 through it on the seafront last weekend and honestly I can't see it in the prints. Lucy was right, I learned more than £8 worth. Also lost one screw, which the cat now owns.