Nikkor-H 300mm f4.5

[richardHaw]

https://richardhaw.com/2018/05/13/repair-nikkor-h-300mm-f4-5-auto/

really busy these days so I am not publishing much. I dont like using this lens much but somebody asked me to write this 

[Akira]

Good job, Rick, as always!

Actually I find this double tripod mount system much more sophisticated than the crude tripod collar.  If you attach an Arca-Swiss plate to each mount, switching the frame between the horizontal and vertical orientations much easier and more precise.  The center of the frame still remains unchanged just like a tripod collar.

[Roland Vink]

My AI 400/5.6 ED (not IF) has a built-in rotating tripod mount. The collar can be rotated to any angle which staying "on target", with click-stops at 90° so I can switch precisely between horizontal and vertical orientations if desired. The best of both worlds.
I think most telephotos with non-removable rotating tripod collars have this feature. Telephotos with removable tripod collars such as the AIS IF-ED lenses with clam-shell style collars, or AF lenses with slip-on collars don't have the click-stops.

[Asle F]

None of the non-removable collars I have access to – 300mm/4 AF, 300mm/2.8 AF-I and 70-200/2.8 AF-S – have click-stops.

[richardHaw]

Yes, the later one has a small ball-bearing for clicking 

damn this lens is heavy! I can use this to smash my noisy neighbors' door

[Øivind Tøien]

No signs of click stop on the fixed collar of my AF 300mm f/4 ED, and it has never been. There is only the dot for alignment.

The fixed collar on the PN-11 on the other hand does have click stops.

[FlyingO]

I've got 2 or 3 of these Nikkor-H 300mm f/4.5 lenses and one of them is optically just about flawless.. mechanically though I have a problem with that one:
The aperture blades do not respond to any aperture ring setting change or trying to get any movement out of the aperture blades at all via the lever at the base/mount of the lens - the auto lever. Could I be correct in my assumption that this problem could be due to a spring just being disconnected? Or is it more likely to be more involved than re-connecting a spring? Thank you to everyone/anyone who decides to offer an opinion or assistance of any kind! I plan on using Rick's article as a guide to getting to the darned aperture assembly. But would really like to hear of a shortcut..! - Mike

[richardHaw]

I've got 2 or 3 of these Nikkor-H 300mm f/4.5 lenses and one of them is optically just about flawless.. mechanically though I have a problem with that one:
The aperture blades do not respond to any aperture ring setting change or trying to get any movement out of the aperture blades at all via the lever at the base/mount of the lens - the auto lever. Could I be correct in my assumption that this problem could be due to a spring just being disconnected? Or is it more likely to be more involved than re-connecting a spring? Thank you to everyone/anyone who decides to offer an opinion or assistance of any kind! I plan on using Rick's article as a guide to getting to the darned aperture assembly. But would really like to hear of a shortcut..! - Mike

that happens sometimes. another cause is grease getting into the iris. i get this at time from lenses i got from the junk shops

[FlyingO]

Thank you. I guess I just assumed that even with a bit of grease or oil on the blades that there would be some reaction to trying to open and close the aperture. I will find out when I have it torn down I guess!

[richardHaw]

you can buy spare springs from model railroad shops 

make sure the tension is just about right. if its not enough it wont close evenly or properly if its too strong it will stress the camera.

[FlyingO]

Thank you! That's good to know. I would not have thought of model train stores as sources.