occhicone98
Newbie
i just go my first screw mount camera, a IIIb with a summar lense. the appeture ring goes from f2 to f4.5 then it stops - it doesnt feel strange - it goes smoothly over those stops...then it stops as if it were at 12.5... i wonder if I am missing something (the way I was missing the slow speed dial...until i read an explanation of its use somewhere on this forum...
) or is someone has another idea...has exerienced this... thanks!
) or is someone has another idea...has exerienced this... thanks!John Shriver
Well-known
The tolerances on the entire aperture mechanism of the Summar are really tight. It absolutely depends on a bit of grease to operate without binding. So it may be binding for lack of lube.
However, it is possible that is was assembled wrong. The slotted ring has two screw holes in the side, that slide past two slots around the barrel. If someone lined it up wrong, the screws into the holes (which connect to the aperture ring) would hit the ends of the slots. You still wouldn't be able to open wider than 2.0, of course, since the blades would stop you.
Any Summar is old enough to deserve a proper CLA. So long as the front glass isn't scoured with scratches, send it off the DAG or Sherry Krauter, and you will get back a much better lens. That old lubricant is almost certainly now a haze on the internal glass surfaces. Some of the derision thrown at the Summar is really just the result of folks using dirty ones.
However, it is possible that is was assembled wrong. The slotted ring has two screw holes in the side, that slide past two slots around the barrel. If someone lined it up wrong, the screws into the holes (which connect to the aperture ring) would hit the ends of the slots. You still wouldn't be able to open wider than 2.0, of course, since the blades would stop you.
Any Summar is old enough to deserve a proper CLA. So long as the front glass isn't scoured with scratches, send it off the DAG or Sherry Krauter, and you will get back a much better lens. That old lubricant is almost certainly now a haze on the internal glass surfaces. Some of the derision thrown at the Summar is really just the result of folks using dirty ones.