Nikon d3000 autofocus issue

The camera is what is known as 'damaged' or 'broken', and will need (expensive) professional repair.

Make sure the A-M switch on the lens is set to A for autofocus.

Also make sure the AE-L button is set to on (pg 144 of your manual) in your menu's otherwise the half-press of the shutter won't allow it to focus.

You did not say which camera body you are using, but you probably have three different auto-focus modes on you camera. You might be using the wrong one.

The modes are as follows:
AF-A Mode: Camera automatically selects single-servo autofocus when AF-A subject is stationary, continuous-servo autofocus when subject is moving. Shutter can only be released if camera is able to focus. AF-S Mode: For stationary subjects. Focus locks when shutter-release button AF-S is pressed halfway. Shutter can only be released when in-focus indicator is displayed.
AF-C Mode: For moving subjects. Camera focuses continuously while AF-C shutter-release button is pressed halfway. Photographs can be taken even when in-focus indicator is not displayed.

Vivitar makes lenses with a variety of mounts. Assuming the lens in question has a Nikon mount then it will fit perfectly well on a D3000. If the lens has a Canon mount, for example, then it will not fit at all.The lens is a manual focus lens, so autofocus will not work. You'll have to focus by yourself.The lens also lacks the electronics to communicate with the camera. You will have to shoot in the Manual exposure mode, setting the shutter speed and aperture yourself, without any help from the camera's light meter.

The Nikon D40 in Auto Focus mode will only allow the shutter to operate when the image is in focus. When looking through the viewfinder, the bottom edge provides information relative to what you are looking at. See the image below:



Item 2 is the focus indicator. It must be illuminated to allow the shutter to release. If it is not illuminated, the lens has not been able to determine the correct focus. This can happen when attempting to take a picture in low light conditions. Make sure that the front facing "focus assist lamp" on the camera (between the shutter release and lens) has not been blocked or disabled (Settings Menu # 09) and try again. Many times, you will see and or hear the lens "hunt" for proper focus - the lens will travel from one end of its focus range to the other trying to find focus. When it can't, it stops and prevents the shutter from releasing. You can get around this "unable to focus" issue by changing the position of the switch on the lens to "Manual Focus" mode, detailed below:

If a lens has an "A - M" switch, move it to "M" to manually focus. If the switch says "M/A - M " then leave on M/A (unless you're going to be taking several or more in manual mode), as these lenses may be focused manually at any time in either position. As soon as you tap the shutter button in M/A you return to autofocus.

More advanced lenses, like the 18-200mm, 70-300mm VR and 18-135mm, and any lens with an M/A position, may be focused manually at any time without moving any switches. Leave them in their A or A/M positions.

I hope this helps and good luck!

What do you have the ISO set to?

Fix your issue with these steps:
1. Try forcing the lens to rotate a fraction of a inch. This will sometimes help the problem. Or simply move the switch from M to A on the lens.
2. Try to switching to a single of the 11 auto focus points. Then try if there are specific points that are the problem.
3. If all auto focus points are fine, try updating the firmware or cleaning the sensors inside the camera behind the mirror. If a one or more points are out of order, also try cleaning the sensors behind the mirror.
4. Detatch the lens from the camera, by applying pressure on the release button and twisting the lens so it can be released. See picture
5. Set the camera selection wheel to manual (M), see picture
6. Turn the camera on, and start the liveView format. This will flip op the mirror inside the camera.
7. Take a dry can blower. Or if in lack, use an empty plastic bottle, without moisture inside, and use it to blow on the autofocus sensors.
They are located at the bottom under the mirror. NOTE Do not blow with your mouth, small amount of moisture will hit the CCD also located here.
8. Turn the camera off
9. Reattach the lens. Push the lens, white point to white point and turn the lens in place.
10. This worked for me, hope it also helped you ;)

For more solutions check Nikon D80 Manual

the nikkor 18-55 lence is no longer u can chage the ed lence into vr lence is upcomming with nikon d3000 mout the coast of the lens is 200$

Set the shooting mode to either Quick-response or Delayed-remote.

Look in the manual under "Shooting Modes."

try pointing the camera on an image which has texture or contrast. have better chances of finding a good image with that.