Nikon SLR Cameras

Why doesn't my Nikkor 35mm AF-S lens autofocus?

Angelo L
Angelo L

I just got a new 35mm f/1.8 G Nikkor lens and I've already slapped it onto my D3100.It works nicely, except for one thing - the autofocus doesn't work.

Supposedly it's an AF-S lens, so it has an SWM, like Canon's USM or Sigma's HSM. This piece of tech should allow for overriding the focus when in AF mode by just twisting the focusing ring as if you were focusing manually.

But the problem is, there's nothing for me to override, since the camera won't focus so I have to focus it manually. This is the same in both modes, AF or manual.

The camera body knows it's in AF mode (called M/A mode on the lens) since it flashes the AF assist light. But that's all it ever does. It just doesn't autofocus.

I mean, the focus doesn't move at all. The focus only changes when I change it manually. I've read the manual for the lens (which is only long because it's in 12 languages, 5 pages for each language, and doesn't help me whatsoever) and for the camera (with which I haven't found anything about manual focus override or the SWM tech).

I've tried messing around with the AF-L button but it didn't really change anything. The lens manual says something about an AF-ON button, which I can only assume is the same as the AE-L/AF-L button.

Is there anything I can do to try to fix it, or do I have to call Nikon or go to the one and only Nikon service center in my country (which isn't even owned by Nikon)?

Added (1). Also, my 18-55 VR lens focuses just as it should. And the AF assist lamp only lights up when it should, not all the time with my 35mm.

Guest
Guest

You got a faulty one. Take it back to where you bought it. If your sure it's a g series and not a d series that is.

Guest
Guest

Exchange the lens, the autofocus motor is supposed to be in the lens for the D3100, so try a exchange, otherwise the autofocus motor may be in the body and you are in for a repair bill if this is the case

It's also advisable to try a lens with known work autofocus and this one

*I have researched this and I do recall reading in-body autofocus a while back and now, there's little info online about this*

Guest
Guest

It does seem that you may have a fault with the lens. Here is a link that will give you all the information about your lens.

http://www.dpreview.com/..._1p8g_n15/

Guest
Guest

The lens should of course auto-focus on a D3100 since this lens has a built it motor, while the D3100 does not have a motor built in the body. Try to put another lens (with built in motor) on the D3100 to ensure that it's not the body that is malfunctioning. If other auto-focus lenses work, then you should change the 35mm 1.8 for a new one.