I battled this problem yesterday and it's very frustrating.
I don't get why while in single point, I have to press the ok button to select the centre focal point for the light to come on. I can be the judge of whether the focus was achieved or not but without it coming on, no focus will be achieved and I just stand there stupidly not being able to take the shot.

I really hope Nikon fixes this PROBLEM in a future firmware update.

studio460 said:
Wait a sec.! Couldn't I use the SU-800's IR illuminator to perform a simple AF-assist function? I mean, I wouldn't be "commanding" any other flash units (nor would I be firing the built-in flash, obviously). Does this work?

Or, for that matter, what about the one on your SC-29? Does it light up with no flash attached?

jonnyapple said:
. . . The higher-end speedlights (SB-600, SB-700, 800, 900) have an AF assist light that works better than the camera's built-in one if you like to use flash.

Yes, I have both an SB-800 and an SC-29, both of which have great, built-in IR illuminators. But, I'm often shooting in very low light, with neither my SB-800 or SC-29 attached, and it's difficult to auto-focus.

I wish there was a separate, Nikon IR illuminator-only product which looked/worked just like an SC-29 (without the cable), that you could attach to your hot-shoe, and became activated when half-depressing your shutter release. I know that Sony (or someone else, not Nikon) made an IR illuminator in the past, but you would have to keep it turned on all the time.

Wait a sec.! Couldn't I use the SU-800's IR illuminator to perform a simple AF-assist function? I mean, I wouldn't be "commanding" any other flash units (nor would I be firing the built-in flash, obviously). Does this work?

P.S. I've been dying to buy one of these (for the actual "commanding" capability for which it was designed) for as long as I can remember, but never got around to ordering one--this is an excellent "excuse" to get one now!

go to menu - custom settings and choose whether the built in AF assist illuminator lights to assist the focus operation when lighting is poor. you get to choose what auto focus modes it will be on and what modes it will be off.

This is explained in page 210 of he manual that came with the camera, section a7.

I am not saying that people do not read the manual, and Tamkon has stated that de does not have one,but I have found that the D7000 is a sofisticated camera and a lot of the problems that people have been having can be cured by reading the manual.

Using a camera for the last 150 years does not mean that you do not have to read the manual, it helps.

Let he without sins pelt the first stone....

The 50mm 1.8 doesn't block it from any of the frame that's visible with that on, but the only place you really need it is in the center of the frame where that central AF sensor is. The higher-end speedlights (SB-600, SB-700, 800, 900) have an AF assist light that works better than the camera's built-in one if you like to use flash.
Welcome to the forum, PH and pbull.

jonnyapple said:
If it's a shadow that covers the left half of the image, it's probably the shadow of the lens/hood. That's normal and you might be able to fix it if you take the lens hood off (and you might not).

Jonnyapple... Yes it's that shadow... Thank you, at least now I know that it's normal... Less taking the hood off lessens the shadow, but I just like what you said it doesn't really disappear... Thank you

...will it happen to other lenses or there is a lens where it will not obstruct the light? Thank you again

Is the motor drive set to continuous? It's in the manual. You can't use the motor drive other than single. Also AF has to be set to single servo. D300s auto illumination is poo poo'd too. There are specific criteria that must be met for it to work. RTFM, I remembered to after grappling with my own AF assist issues just last weekend. The manual has specific instructions that do work. Later, with my SB-900 I was able to take pictures in total darkness, but before making the camera auto focus changes, even the AF assist on the flash did not come on.

If it's a shadow that covers the left half of the image, it's probably the shadow of the lens/hood. That's normal and you might be able to fix it if you take the lens hood off (and you might not).

Hi... Just bought my d7000.. And I'm having a problem with it's Af illuminator using my nikkor 18-105mm lens, whenever it's activated, a shadow is shown through the viewfinder, but it doesn't affect the picture. It just bothers me because I'm wondering if it's a factory defect or it's just a typical occurrence with certain lens. I also don't have other lenses to try. Needs help... Thank you

This will probably 'erk some people. ;)

Page 301 (At least on the online pdf) in your user's manual.

http://www.nikonusa.com/pdf/manuals/noprint/D7000_ENnoprint.pdf

I seriously doubt anything is broken. Probably just a combination of settings.

Weird.

I thought my D7000's AF light was "broken" as well. I only just tested it a few days ago at Disneyland. I usually have my AF light off, since it's distracting to my subjects, but in the pitch black of the park at night, I turned it on. No light. Unfortunately, I'm always shooting in single-point AF, not-in-the-center point, in AF-S mode. So, I guess that's the answer--it simply doesn't "work" in that mode! Thanks for pointing that out!

@fisherman10 oh great mate!! thanks alot.. its fully working now.. again.. thanks a lot to everyone who tried to help :)

@tamkond

change to M,A,S,P mode, press and hold the button at the af switch, turn your thumb dial and it'll change between af-a, af-s and af-c.

also make sure to turn your pointer dial while the af button is pressed to change it to auto multi point selection or if it is single point, make sure to press the ok button to select the centre focal point.

this will make the af assist light come on when light levels are low.

@VaBan i tried what you suggested.. and it didnt worked.. i think its the AF-C thats stopping it from lighting up.. everytime i switch to M,A,S,P mode the AF changes to AF-C and when i switch to any other modes except MASP.. it changes back to AF-A.. what could be the issue? and how to resolve it?

I'm not sure about d7000 but my d90 will not light up if there is enough light, if i not using the center auto focus point and if i'm in AF-C.
Try to set the camera in manual mode, the focus point in the center and AF-S and put your hand in front of the lens. this should work...
sorry for my English...

@TaoTeJared i do know that it will light up if needed.. i just did a few test.. swapped lens with my D3100 and the AF assist light went on.. it narrowed down the problem to the D7000.. the AF assist light doesn't light whenever i use M,A,S,P.. but worked fine with the other presets.. again i tried using an af-s nikkor 18-55 vr and still it doesn't light up whenever i use MASP.. i have AF single servo on, AF area in normal mode, and AF assist light on... the AF mode indicator changes to AF-C when i turn the mode dial to MASP and changes to AF-A when i turn to other modes.. and thats when the AF assist light lights up.. what do i need to be able to use the AF assist light when using the MASP modes? i didn't encounter this problem with my D3100

set your AF points to auto or use the middle point.

TamKonD7000 said:
i haven't read my camera manual cause it's in japanese language..

You can down load an English version from Nikon.

If it is needed it will use it - if not, it won't. Also depending on what program mode you set your dial to it may or may not light. I'm guessing you have the AF assist light turned off in the settings menu. Look in the AF setting bank of menu items.

whats up guys.. i'm new to this forum and i just got my d7000 and a tamron af 18-270 lens.. ok now my problem is the AF assist light is not working.. i noticed it just a while ago and thought that maybe the tamron lens isn't compatible with the AF assist light.. so i tried using my nikkor af-s 55-300 but still the light doesn't go on.. i reseted every settings but still it doesn't work.. what could be the problem? i haven't read my camera manual cause it's in japanese language..

thanks in advance guys \m/