+ Reply to Thread
Page 2 of 2 FirstFirst 12
Results 11 to 17 of 17
  1. #11
    Senior Member

    Re: Probably stupid question about AI-s lens and D7100

    Thanks Love Nikon. That is exactly what I was asking. Unfortunately it appears that my aperture ring does not
    change the aperture.


    › See More: Probably stupid question about AI-s lens and D7100



  2. #12
    Senior Member
    aroy's Avatar

    Re: Probably stupid question about AI-s lens and D7100

    Quote Originally Posted by ffergie View Post
    Thanks Love Nikon. That is exactly what I was asking. Unfortunately it appears that my aperture ring does not
    change the aperture.
    OK. Here is how most of the Nikon lenses with mechanical aperture work
    . The aperture ring moves a "lever" (aperture lever) inside the lens.
    . There is a "feeler" lever on the lens back. In normal position it keeps the aperture fully open. Moving it will change the aperture opening. It will move till it reaches the aperture "lever" inside the lens. That closes the aperture to the value set by the aperture ring on the lens.
    . There is a corresponding feeler on the camera body, which moves the feeler on the lens
    . In older manual cameras, the body feeler would just move the lens feeler, and it stops when it reaches the aperture "lever" in the lens. So the aperture is stopped down to the value set by the aperture ring.
    . In modern cameras, the body feeler movement is controlled by the body, and it moves to what ever aperture is set by the body, provided the lens has a CPU, other wise (as in case of AIS lenses with no CPU) you set the aperture on the lens and the body just closes the aperture to what ever is set on the lens.

    Now if you mount AIS lens on a modern body, the aperture is at its maximum (fully open). It is only when you shoot that the aperture stops down to the value set by the aperture ring.
    D300, D3300
    105F2.8 AIS, 70-300 G, 50F1.8 AF, 16-85G ED VR, 18-55DX VRII, AFS DX 35mm F1.8
    2 x SB-800

  3. #13
    Senior Member

    Re: Probably stupid question about AI-s lens and D7100

    Thanks for the reply, aroy. But I should still be able to see the aperture move when I have the lens of camera and rotate the aperture ring, correct? The aperture is not stuck as it opens and closes when I move the lever on the camera side of the lens but there is no movement when I turn the aperture ring, regardless. Thanks

  4. #14
    Senior Member
    nzswift's Avatar

    Re: Probably stupid question about AI-s lens and D7100

    Off camera an AIS lens aperture should vary as the aperture dial is turned from wide to tiny. If yours isn't doing this there is something strange happening.

  5. #15
    Senior Member
    aroy's Avatar

    Re: Probably stupid question about AI-s lens and D7100

    Quote Originally Posted by ffergie View Post
    Thanks for the reply, aroy. But I should still be able to see the aperture move when I have the lens of camera and rotate the aperture ring, correct? The aperture is not stuck as it opens and closes when I move the lever on the camera side of the lens but there is no movement when I turn the aperture ring, regardless. Thanks
    As I had explained, moving the aperture ring moves the internal lever only. Here is what you can do to check whether the aperture is set, with the lens off the camera

    1. Set the aperture to max, say F/22. Look into the lens from back. The aperture is wide open. Now push the aperture feeler lever full. The aperture will have closed to F/22.

    2. Set the aperture to F/8. Look into the lens from back. The aperture is wide open. Now push the aperture feeler lever full. The aperture will have closed to F/8, which is wider than F/22.

    3. Set the aperture to min, say F/2.8. Look into the lens from back. The aperture is wide open. Now push the aperture feeler lever full. The aperture will remain wide open.

    So you have verified that the aperture changes with the aperture ring (but only when the shot is fired). The reason for this behavious is as follows

    . Initially the aperture would change instantaneously when you used the aperture ring.
    . This meant that though you got DOF preview always, at higher F stops the image would be pretty dark, so most of us would focus at aperture fully open and then stop it down for shots. In the heat of the moment that step was often forgotten, resulting in blown shots (that was in full manual era), and you realised it only when the film was developed.
    . So camera manufacturers came up with what some called "Auto Aperture". The lens would remain wide open (for ease of focusing), and when you fired the shutter, the aperture would change to that set by the aperture ring. In this case you always had a method of getting the DOF preview, where the aperture would close to the set value.
    D300, D3300
    105F2.8 AIS, 70-300 G, 50F1.8 AF, 16-85G ED VR, 18-55DX VRII, AFS DX 35mm F1.8
    2 x SB-800

  6. #16
    Senior Member

    Re: Probably stupid question about AI-s lens and D7100

    Thanks, that is what I suspected. The lens has luckily been able to be returned.

  7. #17
    Senior Member
    WayneF's Avatar

    Re: Probably stupid question about AI-s lens and D7100

    Quote Originally Posted by ffergie View Post
    Sorry if this is a dumb question but I have browsed the groups and cannot find the answer to this.
    I have a D7100 and I bought a Nikon AI-s 105mm f/4 lens and PN-11 to experiment with macro photography.
    When the lens is off the camera and I turn the aperture ring, the aperture opening does not change but when
    I put the lens on the camera and turn the aperture ring, the camera display changes to match the lens
    aperture setting.
    My question: is there a sure way to find out if the lens is working as it should? I thought that the aperture
    should be seen to physically change if I turn the aperture ring while it is off camera.
    Thanks in advance
    This is entirely normal. The lens is always wide open, to make the image be brighter in the viewfinder, and to help the camera to focus. Only when you press the shutter button for the actual picture does the lens stop down to the selected aperture, just for the duration of the shutter exposure.

    You can press the Depth of Field Preview button (next to the lens, below the shutter button) to cause it to stop down for preview purposes.





Quick Reply Quick Reply

If you are already a member, please login above before posting.

Posting Permissions

  • You may post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
  •