non-cpu lenses

Discussion in 'Nikon' started by leo_grillo, Dec 19, 2009.

  1. I have my D700 set up for light, fast work. 50mm, 85mm primes. Last night I needed a 24mm and I remembered that I had one in the old film kit. So for the first time I found myself using the non-cpu program.
    But ... I can't find it in any manual on any Nikon Dslr, in any third-party book, or in any posts here ... how to "de-select" the "non-cpu" choice when the cpu lenses go back on!
    Moreover, my "info" screen still says "non-cpu" when I put on the newer lens again. Anyone know this one??
  2. Hmm. Was this an AI or AIS mount lens?
  3. ShunCheung

    ShunCheung Administrator

    When you mount a lens with CPU back onto the D700, the camera should detect the CPU immediately and automatically. If that doesn't happen, could you try cleaning the electronic contacts around the lens mount, on both the body and the lens?
    Are you having the same problem with multiple lenses with CPU?
  4. AI-s ... but it's the camera program that is the issue.
  5. Leo, I'm sorry.
    The reason you can't select this is because a properly working camera always knows when you've gone back to using a CPU lens. The only way it wouldn't know that you've switched back is if the camera got damaged by the manual focus lens.
    I think that's why Matt was asking if it was Ai or Ai-S, becase a "pre-AI" lens can damage the lens mount of a modern camera. If you tell us the serial number of the 24, I can check if it's "safe".
  6. Thanks Joseph,
    #222289 -- I think it's a bug in the firmware that there is no way to cancel this. If it were automatic, I'd expect the info screen to reflect that. But it still says "non-cpu" lens, though the newer lens works fine.
  7. Shun, it is all working fine, but the INFO screen still says "non-cpu" -- though the cpu lens works fine. Bothers me that there is a contradiction --and nobody has ever stated how to cancel the manual non-cpu selection.
  8. ShunCheung

    ShunCheung Administrator

    Leo, I actually tested all of that on my D700 just now, mounting my 35mm/f1.4 AI-S and then an AF lens on it. My D700 has no such problem.
    Again, there is no way to explicitly cancel the manual non-CPU lens selection because the camera should automatically cancel it when you mount another lens with CPU back on.
  9. Shun, thanks ... the lens appears to cancel when the CPU lens is returned. But if I hit the info screen on the back of the camera, it still says "non-cpu" in the SHOOT menu line, though it's registering the settings from the CPU lens.
  10. PS: I had been scrolling to a non-programmed file number, like "#9" instead of #1-3 where my non-cpu data resides. I did this "in case" but I shouldn't have to go to an empty slot. That got me looking for an answer. In all the manuals from all the cameras that have this feature, none say a thing about what happens when you put a CPU lens back on.
  11. That's because it (the manual) doesn't need to say what it does when you put a CPU lens back on. The camera should simply go back to acting like it has a CPU lens mounted.
  12. Have you tried to do a reset to the camera? If not, reset it, then shut it off and then start it one more time with the right lens mounted.
  13. Matt, it's everybody's user book too. Everything seems to be working fine -- just a missing piece of the puzzle. Thank you guys,
  14. There is nothing to worry about. "Non-CPU" in this context means that next time you attach a lens without CPU, it is identified with the data you already have entered. There is no "reset" as such and nothing to worry about. Any AF/AFS/AFI/Ai-P lens will override whatever the non-CPU lens menu contains. It's a virtually fool-proof system. If you have only a single lens without CPU, the camera will always be set correctly once you put it back on the camera. If you have several non-CPU lenses, then you have to select the slot to be used.
  15. I use non CPU lenses on my Fuji S-1 Pro DSLR which is based on Nikon N60 film camera. It only works on Manual and there is no metering. I bracket and go from there, or use a handheld meter or the Histogram.
  16. Shun, it is all working fine, but the INFO screen still says "non-cpu" -- though the cpu lens works fine. Bothers me that there is a contradiction --and nobody has ever stated how to cancel the manual non-cpu selection.
    Here's what I think may be confusing you. The INFO shows that you have assigned the Function button to non-CPU lens settings. It doesn't mean that the non-CPU lens setting is still in play, just what the FUNC is set to do. You can reassign the FUNC to something else and thus INFO would then show whatever that was instead of non-CPU.
    I hope my explanation is not too confusing on top of the original confusion!
  17. Martha, thanks! That is exactly what happened!
    I don't use the info screen much -- this camera is for one purpose and today I doubled it for something else. It just blew my mind that there was no explanation anywhere -- even about it being automatic. Glad I remembered these boards -- there are no answers anywhere else! Thanks again!

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