Baybers
Established
Hello all. I received this lens yesterday and while the optics are very good and the focus is smooth it was apparent the optical block was not sitting correctly in the helical. Upon removing the module I discovered a fabric like 'shim' twisted around the barrel. As is said in Australia 'a very dodgy' piece of work. I'm hoping someone can help with advice about constructing some shims or any other suggestions. Thank you in advance.
Attachments
The picture of the complete lens: is that with the homemade shim in place?
That looks "about right" for a jupiter-3. Put up a picture showing the aperture marks, if the numbers are screwing past the rim of the barrel- likely a problem. If the numbers and any part of the lines are showing, and the F1.5 is showing up at the index dot- someone went through trouble to adjust it but used a homemade shim.
I've made shims from the leg of an old tripod, cut with a pipe cutter and polished down.
Faster and easier: Paper, Kitchen foil, and Wire. I;ve used 1mm solid wire for coarse and braided wire for thin shims.
That looks "about right" for a jupiter-3. Put up a picture showing the aperture marks, if the numbers are screwing past the rim of the barrel- likely a problem. If the numbers and any part of the lines are showing, and the F1.5 is showing up at the index dot- someone went through trouble to adjust it but used a homemade shim.
I've made shims from the leg of an old tripod, cut with a pipe cutter and polished down.
Faster and easier: Paper, Kitchen foil, and Wire. I;ve used 1mm solid wire for coarse and braided wire for thin shims.
Baybers
Established
The homemade shim was in place in that photo and the aperture scale was on the opposite side to the dot. Here is the lens without shim, the optical block screwed in as far as it will go and the aperture wide open. It would seem it needs to go back at least a 3/4 turn.
Attachments
That was a real hack job with the shim!
At This point- try to assess focus at infinity if you have a mirrorless camera. Set the focus to the infinity mark and unscrew the lens until infinity is good. Figure each full turn is 0.5mm.
At This point- try to assess focus at infinity if you have a mirrorless camera. Set the focus to the infinity mark and unscrew the lens until infinity is good. Figure each full turn is 0.5mm.
Baybers
Established
Cheers Brian and many thanks, I've agreed with the seller to return the lens; I'm too nervous that there might be other issues and he was reluctant to meet the cost for a professional to undertake the repair here in Australia. As we talked over the past two days it became apparent he did not know much about what he was selling, or at least it sounded as such. All the best!
flavio81
Well-known
The shim was probably correcting a factory misadjustment, but then probably the mount loosened up.