I got a few of those plastic "Cosina" 35-70mm f3.5-4.8 zoom lenses 'free' with some cameras. Actually both came on FM-10 bodies.
Anyway, they are not bad lenses. Clear optics sometimes are more important than lens design. Some of my old pre-AI lenses are not all that clear in the optic department (after cleaning).
So I thougt it would be nice to have one of these lense on my Nikon F. Of course the lens works fine in stop down mode. However, I find I can't turn the shutter speed knob while my right hand has the aperture preview button down. Reaching over with my left hand covers the illumination of the shutter speed readout. That problem gave me the idea of adding the aperture coupling prongs to one of these inexpensive "Cosina" lenses.
I could find very little information about adding meter prongs to Nikon AI lenses which don't already have the prongs. For example what is the pitch and diameter of the screw thread? I guess I have to figure it all out.
As many of you know there are already dimples to mark where the screws holes need to be on many lenses.
Anyway, they are not bad lenses. Clear optics sometimes are more important than lens design. Some of my old pre-AI lenses are not all that clear in the optic department (after cleaning).
So I thougt it would be nice to have one of these lense on my Nikon F. Of course the lens works fine in stop down mode. However, I find I can't turn the shutter speed knob while my right hand has the aperture preview button down. Reaching over with my left hand covers the illumination of the shutter speed readout. That problem gave me the idea of adding the aperture coupling prongs to one of these inexpensive "Cosina" lenses.
I could find very little information about adding meter prongs to Nikon AI lenses which don't already have the prongs. For example what is the pitch and diameter of the screw thread? I guess I have to figure it all out.
As many of you know there are already dimples to mark where the screws holes need to be on many lenses.
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