Nikkor 1.4 AF loose screw problem.

Discussion in 'Nikon' started by luis_dudamel, May 30, 2016.

  1. Hello to all.
    I just got as a gift from my uncle, a 50mm 1.4AF (The older version).
    One thing, is the blades stop at f/8. The dial even goes all the way to f/16 just it won't close more than f/8. Is this too bad to fix? I can live with it, i wanna use it in 1.4 anyways.
    It's in pretty good condition, and when i was handling it, it accidentally fell from my lap. Nothing broke (i guess), just the tiny screw that rotates (the focus system) was out of the lens. I just put it back in, and the lens is fine, the screw just sometimes falls out the lens.

    I can live with this, but, is it in some way going to damage my camera body? What can i do before taking it to a technician?
    Just noticed, on Live View, it has problems focusing. It just stops focusing and I can hear the motor trying to do the focus, but it just won't do it.
  2. That screw is the drive for the auto focus (this lens having no motor in it, and requiring the motor in the camera to do the job). It certainly should not fall out, and it's pretty sure it's broken if it does. When you manually focus the lens, you should see that screw turning.
    You could probably still use it as a manual focus lens if you leave out the broken part, but I'd worry still a little that something else is loose inside and preventing the aperture from working correctly.
  3. It does work on manual and AF. It just worries me, that being loose can damage some camera mechanism.
  4. Luis, you're not listening.
    in your initial statement you say it's not working, then you say it is?

    You really need to pass from denial to actually getting the lens serviced by somebody.
    "Little screws" are often quite important and shouldn't "fall off".
  5. You are right.
    It's going to service, then.
    Thanks :)
  6. I doubt it will damage the camera if you remove the loose screw to insure that nothing jams. At that point there will be no AF connection at all with the camera. I think I'd switch to MF to prevent the motor from vainly trying to achieve focus. As for the aperture, I don't think it should damage anything, but if you're locking the aperture ring to use the camera's controls, it will not give proper exposure if the camera thinks it's setting any aperture smaller than F8.
    That's all assuming that something inside the lens does not shift or drift and cause something else to jam. I don't think that will hurt the camera, but it might hurt the lens even more.
    I don't think it should damage the camera, but I think it will be frustrating to use.
  7. Luis; Try looking at They sell online repair manuals that one can buy and download in pdf form for Nikon and different other brands of lens, and they have a low res sample of the lens exploded schematic on each lens page. I didn't see your lens listed, but you could look at the ones for the AF 28mm f2.8 and the AF 35mm f2 lens because they are of the same design as your AF 50mm f1.4.
    Also. If you do a Google search for Nikon Lens Schematic, you'll find a higher res version of the AF 28mm f2.8 lens to help guide you if you want to attempt a repair yourself. I have repaired many of my lenses over the years with and without these schematics. Hint. Take pictures of every phase of the disassembly to guide you in the reassembly. That's if you want go that rout.
  8. Given that the aperture blades also don't close properly, and that there should be a fork inside the lens to hold the "screwdriver" coupling in place; I'd say the lens has been subject to amateur dismantling. If the aperture lever isn't re-assembled in the correct position then it can give the symptom of not stopping the iris blades down fully.
    In short the lens needs to be taken to a competent repairer to be stripped and re-assembled correctly.

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