Tamron 35-70 f/3.5 17A Adaptall-2 Disassembly and Fungus Cleaning
This article is not detailed instructions for disassembly and cleaning of the lens, but only my experience in solving a particular problem — cleaning fungus in the third element on the side of the aperture. I hope it will help those who will need to solve a similar problem.
I bought this lens cheaply because there was a fungus. And I wanted to clean it.
To do this, it was necessary to disassemble the lens. The fungus was small, and consider exactly what element was difficult. I was 100% sure that it is on the second element and became apart from the front.
Tamron 35-70 f/3.5 17A Adaptall-2 optical design. The green color shows the place where the fungus.
Tamron 35-70 f/3.5 17A Disassembling Procedure
I took the lens spanner wrench, insert it into the special notch on the front of the barrel, and started to unscrew the nut counterclockwise.
Red arrows show the position where to insert the spanner wrench
After I nut unscrewed, I began to pull the first lens fungus elements, and it was not under a second. That’s how all the inside of the lens is deceptive. It turns out that the fungus was the third lens on the side of the aperture, but to get there, I had to disassemble the lens differently.
I had access to the third element, which structurally is in the middle of the lens. Pulling the lens on the backside, too, would not avail. The lens had to be dismantled in the middle.
I began to look carefully, at least some hint of how it can be disassembled and found. Under the rubberized ring was a small notch.
The red arrow shows the location of the insert the spanner wrench
I put the thin end of the spanner wrench and began to rotate counterclockwise. Nut succumbed rotation, and thus I can easily make out the lens into two halves.
Dismantled lens. The arrow indicates the lens. which needed to be cleaned
Next, clean the lens is not too difficult. I did not pull it out of the barrel; it was not necessary. At first, I smeared it with saliva and waited 5 minutes. Saliva dissolves perfectly chitin – the material that makes up the majority of fungus.
The lens came to me from Texas. It is a pity that he did not photograph fungus; I want to get rid of it quickly.
Next, after I carefully removed the element with saliva, I rubbed it special cloth, dropping it a modicum of special lens-cleaning fluid.
Further, the lens was assembled the opposite way. When installing the helicoid in the thread, you must see to it that he was exactly where he was pulled out; otherwise, you can remove it and lose focus to infinity, and the scale will not accurately show the focusing distance.
All this work took me a little more than an hour. But if all know in advance how and what to disassemble, we can handle it much faster.
Also, watch, review and sample photos of Tamron 35-70 mm f/ 3.5 Adaptall-2 model 17A