<p>Hello! Thanks for all your answers! <br>
It is, in fact, a manual Nikon Lens Series E, 35mm/f 2.5. The weird thing is that, even though the lens is manual, the camera used to recognize it and now it doesn't. I made a few more trials with other lenses and the photometer works, so I guess the problem would definitely be with the lens. <br>
I also tried the 35mm lens on my digital Nikon and it recognizes the change of aperture from f 0 (?) till f 7, instead of f 22. <br>
What would you say? Is that worse to get fixed? </p>
<p>Thanks again!</p>