Originally posted by Viernes I'm buying an (obviously) used 135 3,5 to feed my Spotmatic.
What's the best way I can make sure the lens is in good shape? I mean, besides scratches an stuff like that.
Thank you all!,
Regards,
Viernes
Take along a small torch and look into the lens from both ends for any crud, mould (filaments, numerous specks or large splotches) and delamination (fuzzy hazy multicoloured areas).
Check the operation of the aperture ring: should be smooth and click "solidly" into detents (there may not be an intermediate detent betweeen the first and second and the penultimate and last settings).
Set the lens to "auto", the apertue to the smallest opening, and push in the aperture operating pin at the mount end of the lens. The aperture blades should work smoothly and evenly (producing a regular hexagon/pentagon, whatever) and spring back quickly when the pin is released.
Operate the focusing ring: the helicoid should operate smoothly -all the way- in either direction.
If possible, put the lens to a suitable camera body (one of their's will do) and check the infinity focus.
Does the mount operate smoothly (no damaged threads)?
Check the filter ring for dings/crossed threads.
Check the front element for dings and scratches (hold so the light reflects back at you -use the torch). The rear element in this lens (the 135) is deeply recessed, so unlikely to be damaged. (Dirt/dust on rear/front elements and/or the filter -if any- can give a false impresion, so remove the filter and clean the lens first)
Look for signs that the lens has been dropped (gouges/dings in the metal work).
The exterior of this lens will be all metal (no rubber) all through, so no problem with derioration/wear of rubber grips, but there may be wear/dings to the finish, which can often be remedied by the judicious use of a felt tipped marking pen.
Check that the Auto/Manual lever operates.
This lens originally came with a front (metal, slip on) and a rear (plastic, screw on) cap, a metal (screw on) custom lens hood and a hard leatherette case. If available, these are a plus. (Ask)