I bought a vintage Tokina 70-210mm F3.5 lens few weeks back. It was great for the money (~30eur) but now the aperture doesn't work right, while disconnected from the body (D3300) it works fine, though I first need to move the aperture lever. When I put it on the body aperture either moves from like 3.5 to 5.6 or is stuck at single aperture (not always the same). I didn't try to disassemble it, didn't drop it, it just stopped working right after I put it on the body. I used this lens for at least a few weeks and it worked fine. Do I have to do something with the aperture lever (I tried putting it in different positions before mounting)? I tried my kit 18-55mm on body and it worked fine so I don't think it's my body (though these are VERY different lenses). I can provide pictures/video if needed (with my crappy phone). Thanks for any help!