[ZombieArmy]

I want to make it clear that I'm not complaining about the seller for this lens, I took the risk. It was labeled as "for parts" and was completely untested, it was sold by a person who didn't know a thing about lenses. I took the risk for the low price of 20 bucks and I'm not here to be upset about that.

What I do want to talk about however is what I should do with the lens? The lens in question is the A 70-210 manual zoom.

Here are some sample shots from the lens itself most at 70mm, but I think 1 at 210mm. All of these are out of camera raws at iso 200.

Here is a 100% crop from a photo:


And here are some links to the full rez photos:

https://puu.sh/vi2jp/f5eb89b75a.jpg

https://puu.sh/vi2j3/abf6247b24.jpg

https://puu.sh/vi2iQ/8c81d0b8b1.jpg

https://puu.sh/vi2jb/3b125fd4fe.jpg

https://puu.sh/vi2jA/3dc4beaf27.jpg

https://puu.sh/vi2j1/d78e374e02.jpg

Here is a pic of the fungus itself, sorry it's not the best but I have a hard time photographing this stuff:





Now I have a few questions.

1. Is the fungus going to keep growing or is it dead?
2. Is it worth repairing this lens? Or would I be better off flipping it when I have money to get a more mint copy?
3. Is this typical IQ from this lens? I think it looks good but I thought I'd ask.

Thanks for the help.

[Fenwoodian]

For a $20 lens, I would not spend any money to have it professionally CLAed.

If you can take apart the lens yourself and clean it, might be worth a try. Might be a good learning experience for you. Lots of great YouTube videos on repairing lenses and even a few on getting rid of fungus in lenses.

If you don't have the requisite tools (spanner wrench, jewelers screwdrivers, etc, etc) to take this lens apart yourself (and you don't care to purchase them) then your best bet would be to give this lens the old "UV from the sun treatment.

Open the aperture as wide as it will go. Put aluminum foil over the rear of the lens, put the lens outside on sunny days with the front element pointing towards the sun (every few hours you will need to re-aim the lens to keep it aimed at the sun). Do this for a few days and it should stop the fungus in its' tracks.

To prevent it from coming back, repeat this UV sun treatment every year, AND keep a desicant next to the lens to keep it dry.

[ZombieArmy]

For a $20 lens, I would not spend any money to have it professionally CLAed.

If you can take apart the lens yourself and clean it, might be worth a try. Might be a good learning experience for you. Lots of great YouTube videos on repairing lenses and even a few on getting rid of fungus in lenses.

If you don't have the requisite tools (spanner wrench, jewelers screwdrivers, etc, etc) to take this lens apart yourself (and you don't care to purchase them) then your best bet would be to give this lens the old "UV from the sun treatment.

Open the aperture as wide as it will go. Put aluminum foil over the rear of the lens, put the lens outside on sunny days with the front element pointing towards the sun (every few hours you will need to re-aim the lens to keep it aimed at the sun). Do this for a few days and it should stop the fungus in its' tracks.

To prevent it from coming back, repeat this UV sun treatment every year, AND keep a desicant next to the lens to keep it dry.

I kind of live in an apartment and putting it outside will just result in it getting smashed or stolen

I wouldn't mind taking a whack at repairing it but I simply can't afford the tools right now.

[kchamber4]

I am looking for some experts to weigh in on this, but I'm not sure this is fungus as much as it is pitting of the coatings or even just very dirty and scratched. I thought fungus appeared more as a string instead of dots. I had a lens similar and after cleaning the front and back lenses with lens cleaner, over 80% of the pits / spots where gone. I haven't seen any come back either.

[ZombieArmy]

I am looking for some experts to weigh in on this, but I'm not sure this is fungus as much as it is pitting of the coatings or even just very dirty and scratched. I thought fungus appeared more as a string instead of dots. I had a lens similar and after cleaning the front and back lenses with lens cleaner, over 80% of the pits / spots where gone. I haven't seen any come back either.

https://puu.sh/vi2xL/e03ea48478.jpg

There is a link to the full rez. There is some "stringiness" in there. It's not severe but it is there. I'm sure some of it is extremely bad dust too.
But it's most certainly inside the lens, the outside is clean.

[Fenwoodian]

For a $20 lens, it certainly takes some nice photos. Just another example of how a lens with plenty of crud/defects in it can still make pretty decent images.

[ZombieArmy]

No, no, no, no, no.

The "UV cure" treatment is hogwash. Any fungus you see in the lens is already dead, and UV does nothing to kill the spores. Simply keep the lens dry, and the fungus won't spread. It will be a banner day when this and the "Fungus jumps from lens to lens!" urban myths finally stop rearing their ugly heads.

Hey I'm glad you came around

I was wondering if you had any idea how hard it would be to clean this lens? Even if only for my own preferences of a lens being clean. I assume zooms must be much harder than primes?

[ZombieArmy]

I'd call this one moderately difficult. It's got 13 elements in 10 groups in it. The hardest ones to get to are the ones immediately adjacent the iris.

Here's an optical diagram:



As you can see, the first cell in the front remains stationary, as do the two in the rear, while the second two in the front float independently. The stationary ones are easy to get out, as the fornt ocmes out in one piece, and IIRC the rear cell is mounted to a tube that screws out entirely. The inner rear might or might not come out with it. Can't remember off the top of my head.

To get the floaters out, I think you have to you need to go in from the sides under the grip and remove the screw pegs holding them into their tracks on the helical. They are then removable from the front. Once you get the cells out, breaking them down to single groups if necessary is pretty self explanatory. You might need to dissolve some threadlocker to get them apart.

I think I'll give it a shot. I actually think I have the screwdriver bits needed to do it. What do you recommend to use for actually cleaning the elements?

[ZombieArmy]

If you disassemble the cells, warm soapy water. If the fungal colonies are stubborn, hydrogen peroxide sometimes works.

If you can't/don't want/don't need to disassemble cells, wiping them off with lighter fluid or acetone will usually do the trick. Use a lens cleaning tissue/kimwipe/etc.

So just some dawn and warm water huh? Sounds good to me!

[ZombieArmy]

Yep, just use your (clean) fingertips to softly scrub the surface with the soap. Rinse with cold water, then with distilled if you have it. Wipe off with lens tissue or microfibver and blow off any dust before putting it back in.

Anything I should look to not break when i'm opening the lens? I hear the A lenses are usually a bit more difficult.

[ZombieArmy]

If you take the tear mount off, be careful not to lose the little bits of the info contact.

Thanks I appreciate it!

[arnold]

The detent ball bearings are known for shooting out. Suggest pulling apart inside a clear plastic bag.