I am using a Nikon D5000 with a 50mm f/1.4 with autofocus. When I try to use manual mode (or aperture priority, or shutter priority), my AF assist beam does not light, which makes it hard for my camera to auto focus. Ocassionally, there is enough light for me to switch over to manual focus but a lot of the time there is not enough light for me to even be able to do that. It does light when I am in several of the auto modes (but not all) but I really don't want to be stuck shooting in auto modes in low-light situations.

So basically, my question is... is there a setting that I am missing? Why does my AF assist beam not light up when I am in any of the priority modes?

  • \$\begingroup\$ Please mark the answer that worked for you as "accepted answer" by checking the check box next to the vote up/down selection. If you would like to comment on the fact that it worked for you, that would make sense in the comments to that question, and not as a new "answer" as it is right now. I have flagged the moderator to help you with this. \$\endgroup\$
    – dpollitt
    Commented Jan 9, 2012 at 17:07

3 Answers 3


The D5000 has a quite specific set of requirements for using the AF assist illuminator outside of the pre-defined scene modes.

  • The lens has to be in autofocus mode (obviously).
  • The autofocus mode must be set to single (AF-S) or using AF-S in AF-A mode.
  • The autofocus area mode must be set to Auto, or if it's set to any of the other modes (Single point, Dynamic or 3D tracking), the centre focus point must be selected.

And of course, the illuminator has to be turned on in the menu system, which is option a2 in the Custom Setting Menu (it's on by default, but it's worth checking).

  • \$\begingroup\$ Just to be extra clear. The illuminator is only useful if the camera con focus on where its pointing, that is why these requirements are there. \$\endgroup\$
    – Itai
    Commented Jan 6, 2012 at 17:27
  • \$\begingroup\$ Thanks, had the same issue with my Nikon D3100 and think it uses the same requirements. Good to know been going nuts trying to figure out why it wasn't firing. \$\endgroup\$
    – Joe Solano
    Commented Jan 10, 2012 at 2:33
  • 2
    \$\begingroup\$ It's all in the manual :) \$\endgroup\$ Commented Jan 10, 2012 at 8:33
  • \$\begingroup\$ thanks been tryin to figure this out myself for a while now...will try it and let u know. \$\endgroup\$
    – user19492
    Commented Apr 21, 2013 at 19:29

Note that the illumination works differently in live view than normal through the eyepiece view. If you think it is not working make sure to check the stuff answered above, but also try it out of live view.

  • 1
    \$\begingroup\$ Interesting. I don't have a D5000 to try it with, but I'm curious. How is it different? \$\endgroup\$
    – mattdm
    Commented Sep 27, 2012 at 20:57
  • \$\begingroup\$ @mattdm, it is different in that it doesn't work in live-view. I just checked on a D5100 and being in live-view disables this. Not 100% sure as I haven't confirmed this from the manual but intuitively it makes sense since live view uses contrast-detection. \$\endgroup\$
    – Unapiedra
    Commented Jun 14, 2014 at 17:45

I had the same problem with my D800. The first thing I did when I got my D800 was to turn off the beep sound and the focus illumination. But 4 months later, having cranked up auto ISO to H2.0, I wanted to test the noise levels of the D800 in very poorly lit situations but focusing wasn't spot on. When I decided to turn on the auto-illumination, it failed to work and I thought of sending in the camera as I thought the lamp was fused or something.

Having tried this solution, it works 100%

  1. Option a8 must be turned on in setup menu
  2. Lens must be between 24-200mm
  3. Focus point must be in the centre

The D800's illuminator will trigger in any mode, even manual.


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