Tamron 20AB has a fungus heart?

V�sen · Joined: 06 Sep 2011 Posts: 38

Hi,,

I recently acquired a Tamron 20AB from ebay. The seller has 100% feedback and wrote " Have very little traces of use. Optics clean without mold and mildew. " in the auction.

At first I was inclined to agree, then I spotted what looked like a strand of hair in the lens (that had no effect on images taken however), and finally I shone an LED light through it and now I don't think it's a strand of hair anymore (but I'm not sure what it is).

Close-up of that strand:

Behind front element:

It's exterior is great, and so does the functionality seem to be. It's rather soft and aberrationy at f/3,5, but closer to f/5 it's great.

Lloydy · Expire: 2022-01-01

I would say the strand is a hair, and if it is behind the front element it will be easy to remove. But the other marks look like fungus. Possibly still cleanable at that stage, but that's not the point, it was sold as a clean lens and it isn't.

Attila · Expire: 2021-11-18

Starter fungus , cleanable well.

V�sen · Joined: 06 Sep 2011 Posts: 38

Thanks for your replies.

The round splotches appear on several elements and even if they are just starting to spread I'm afraid I'm not terribly handy with taking lenses apart, plus I've yet to see a service manual for this lens.

I have contacted the seller about a return and we'll see what sort of a reply I get, if I get one.

This lens is very handy but it looks a bit thin on my A77. The 26A appears a little bit thicker, judging by the diameters given by adaptall2.org.

V�sen · Joined: 06 Sep 2011 Posts: 38

Hello again.

I returned the 20AB and bought a 20A on the bay.

"THE LENS GLASS IS CLEAR AND BRIGHT, WITH NO SCRATCHES, BLEMISHES OR FUNGUS "

What's this then? Victim of a bad cleaning session? (View from the front. Stuff is on a middle element; does not appear in images at f/8 from what I can tell)

The lens smells faintly of men's cologne.

Attila · Expire: 2021-11-18

V�sen · Joined: 06 Sep 2011 Posts: 38

Ah. It doesn't look like dust to me, so I will assume it's traces from a botched cleaning attempt.

The lens handles fantastically and 70-150 is a very useful range on APS-C. I find one click down, as per the lens f/4, sharp enough for general use. It's a little odd that you push to zoom out and pull to zoom in but I have no other push-pull zoom so it takes no getting used to. I've also ordered an adapter for the NEX to see how it works on it compared to on the A77.

At the lens' f/4 (I say "the lens'" because adaptall2.org reports about a review saying this lens' f/3,5 is closer to f/4. What I mean is one click down), unsharpened:

Now if it would just stop smelling like it was about to put on the jean jacket and go out cruising in an old Desoto it'd be almost perfect.

Attila · Expire: 2021-11-18

Good lens fore sure I had in past also, enjoy!

V�sen · Joined: 06 Sep 2011 Posts: 38

I will

One final note: It isn't very well balanced on my NEX-3. I have to hold a wrist bent most of the time and it's slightly awkward. The adapter for it is also significantly longer than the one for Alpha mount. It works very well on the A77 however. I may be a bit biased however as the only other lenses I've used with the NEX-3 are small M39s and the Sigma 19mm.

Lloydy · Expire: 2022-01-01

With a big lens on the NEX treat it as a camera on the back of the lens and not as a lens on the front of a camera, hold the lens and balance it with the camera. If you are used to a DSLR or a SLR it's a bit alien. It works for me. Wink