Nikkor-H 18cm f2.5 question

[henryr]

I bought a Nikkor 18cm lens about 15 years ago. The glass is very nice, and everything works smoothly. However, when I got it, the depth of field collar was missing its two screws. Looking into the empty screw holes, there seems nothing for them to engage. What do these screws do and are some internal parts missing?

Thanks,
Henry Rancourt

 

[Sonnar Brian]

I am guessing that someone had a Tab on the ring to help stop it down. I checked two books on Nikon Rangefinder equipment- they do not show in the pictures.

IF a tab were placed on the ring, the user would be able to "feel" by position what F-Stop was in use.

On my 25cm F4 Nikkor-Q: "Long ago" someone modified the aperture ring and barrel with "Bumps" in it to "feel" the F-Stop setting.

 

[henryr]

Thanks, you got it right. Turns out the 18cm f2.5 had a small metal piece under the aperture ring that was held in place with the two screws. The purpose was, as you say, to feel what f stop was being used by topping the aperture collar from going past the selected f stop setting. Any ideas where I could get the metal piece would be greatly appreciated.

 

[henryr]

Does anyone know where I could get the screws, for the aperture ring, for my Nikkor-h 18cm lens? If I could get the screws, I could make the small block that they attach to.