There are only A and M settings, no A/M. but I just noticed that Nikon website has mentioned three focus modes for this lens: Auto, Manual and Manual/Auto

I'm confused if this is only a typo or is it safe to manually focus with this lens when the lens is in Auto mode?

  • \$\begingroup\$ This is an interesting observation! Are there any lenses that are not safe to manual focus while in auto mode? That seems like a critical design flaw... \$\endgroup\$
    – Drew
    Commented Feb 3, 2013 at 0:04
  • 2
    \$\begingroup\$ @AndrewHeath Yes. It can damage the AF motor for most non-USM lenses. (Many Pentax lenses have a "quick-shift clutch mechanism to avoid this.) \$\endgroup\$
    – mattdm
    Commented Feb 3, 2013 at 0:09
  • \$\begingroup\$ In case of Nikon, in addition to the old AF lenses which do not have a motor, also some cheap AF-S lenses (AF-S is the equivalent of USM) are not safe to MF when in AF mode. These basically are the kit lenses: 18-55, 55-200 and 55-300. \$\endgroup\$
    – Marco Mp
    Commented Feb 3, 2013 at 8:37

2 Answers 2


Page 15 of the manual answers the question:

Manual focusing is possible even when the lens A-M mode switch is set to A.

Mind you, the camera should be in AF-S mode and then you use the ring to fine tune, which isn't a full-range manual adjust, it's for tuning the AF result.

  • \$\begingroup\$ Which manual are you referring to? \$\endgroup\$
    – Omne
    Commented Feb 3, 2013 at 13:29
  • \$\begingroup\$ OK, I've found similar answer in page 315 of the camera's manual. it also mentions that we should not use the focus ring when the camera is focusing. \$\endgroup\$
    – Omne
    Commented Feb 3, 2013 at 13:37
  • 2
    \$\begingroup\$ Yes, you should not use it when focusing, or in AF-C (continuous) mode. Only AF-S (single) mode as John pointed out. This is only meant to be used after you've done a half-shutter press and AF-S has focused the lens. Only then can you adjust focus and then fully depress the shutter release button. \$\endgroup\$
    – MikeW
    Commented Feb 3, 2013 at 17:29

According to the information below, I am led to believe that it is not safe. However the lens manual trumps anything, so if the manual says it's ok, I'd have to assume it's ok.

Nikon terminology is confusing. There are two similar sounding modes:

  • A/M, which is autofocus with manual override (the one you want), and
  • M/A, which apparently is the ability to switch between A and M with little or no lag

The 18-105mm does not have A/M mode, which is the one which allows for manual override. It may have M/A mode, as the specification seems to indicate. This is not the same thing as the A/M switch you see on other lenses.

According to this thread, Nikon support have indicated that while you can manually override focus when in A mode on the 18-105mm, you should not do this regularly.

...there is an amount of movement on the focus ring to allow you to also focus, however this should not be done on a regular basis


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