AI-S Nikkor 400 2.8 IF-ED - hard/stiff aperture ring

[Imagelover]

Dear members of Nikongear.net. I have an AI-S Nikkor 400mm f2.8 IF-ED back from the mid eighties with a hard/stiff aperture ring. Do you have any suggestions which lubricant/oil/grease to use to make it easier and smoother to turn? Your advice is greatly appreciated! Thanks! Any experiences using this lens are welcome too.

[Birna Rørslett]

The aperture ring might collect an unlikely amount of dirt and grime over the years. Thus remove it -- carefully -- and gentle clean it.

The 400/2.8 is very heavy and requires a stable tripod in order to deliver best results.

[Imagelover]

Thanks for your advice, Birna! I have the Gitzo GT5533LS with the FLM Ball Head CB-58 FT II for the purpose. The Tripod/Ball Head is also usable for my AI-S 300 2.0 IF-ED lens. I will try to remove the aperture ring and do what said. Thanks again!

[Birna Rørslett]

Please note that *only* JIS screwdrivers should be used. You stand a real risk of stripping the bayonet screw heads otherwise.

[Imagelover]

Thanks again, Birna! I'll try to get the right one asking for it in a local affair.

[Erik Lund]

These heavy lenses are prone to getting aperture ring damage,,,


The shear weight makes any impact to the aperture ring with something hard, a potential of bending the ring, making it tight/rough, so examine the edge, along the F-mount for impact damage.


JIS: EU shop,,, 




https://www.micro-tools.de/en/Screwdrivers/Kits/JIS-Type/58-0319.html

[Imagelover]

Thanks for advice and information, Erik! I'll try to fint a set tomorrow.

[Birna Rørslett]

I can recommend Microtools. Bought several sets of JIS drivers there over the years.

[Imagelover]

Thanks, Birna!

[Zang]

I did buy Micro Tools JIS screwdrivers based on recommendation here and when they are OK, they are a bit too thin and not robust enough. I ended up stripped one of the bayonet mount screws. I would suggest buying something stronger.

[Birna Rørslett]

You need to find a perfect match for the driver to the actual screw head. Then stripping risk is minimised. Also, use a quick back-and-forth movement combined with downwards pressure once the screwdriver engages the head to get the screw loose.

AIS lenses tend not to have screws as reluctant of removal as those of the older generation(s).

[Zang]

I did exactly the same way. The problem was the screwdrivers from the link were a bit small and delicate.

[CS]

You need to find a perfect match for the driver to the actual screw head. Then stripping risk is minimised.

Best case scenario, although not always possible, is to take the screw head (in this case the lens) to the tool source to check for  good match, before you buy tool. Or, try to talk to repair facility to see exactly what tool, and exact brand name, they use. Must be a gajillion different screw heads, and finding the correct tool one needs can be frustrating. I prefer Allen head screws, but unfortunately not many manufacturers accommodate their use.

[pluton]

I did exactly the same way. The problem was the screwdrivers from the link were a bit small and delicate.

JIS-compatible screwdrivers are available in all imaginable configurations:  Longer, shorter, thin or thick handle, thin or thicker shaft, etc.  Thicker, substantial handle diameters are usually better(especially for Nikon mount screws), unless the accompanying thicker shaft cannot get past an interfering obstruction or through a access hole.  It's good to have a variety of these tools on hand.
Carl's suggestion to match the screwdriver tip to the screw is, of course, the ideal procedure...if you can buy the drivers locally.

[Zang]

The screw heads matched perfectly, just the screw drivers were too delicate. The set was the only available from Micro Tools where I ordered. Jis screwdrivers' availability is next to none here.