For the last few days I have been working with my Nikon Series E 1:1.8 lens. Today I noticed that the shutter speed had gone from 1/40s to 1/50s. This was on my Nikon D70 and I did not do anything different. I do not believe I could do anything different since the lens can only be used on Manual. The Shutter Speed automatically defaulted to 1/40s. The only adjustments I can make is with the f/stop ring. Same weather as yesterday, sunny and bright. For example I used it most the day yesterday, adjusting f/stops and the shutter speed never left 1/40s.
Thanks for any assistance offered.
Antonio