Nikon D3000 autofocus problems
I have had my D3000 for about two years and I have never came across this problem. I can't take a photo when I'm in any mode besides guide or when I press the AE-L/AF-L button but the photos come out blurry. I have reset my camera and my shooting options but it still won't focus. My focus mode IS on autofocus. I have the original 18-55 mm lens the camera come with and I would like to know if this is a problem I can fix or if I should take it to a shop.
Recently I had a problem with my photos where the bottom half would be black, I figured out it was a mirror problem and I fixed it. Now my autofocus won't work, could these problems be related and can I fix the autofocus problem in a small amount of time?
My Canon camera has problems if I delete or alter anything on the memory card. This seems to be a common enough problem that I've heard people say you should NEVER use a camera's delete function.
Possibly a timing issue, since deleting files can cause at least some new files to be fragmented.
After you upload your images to your computer, delete EVERYTHING (also empty the trash if using a MAC) on the memory card before using it again.
Try this, along with temporarily taking out the camera's battery.
It may or may not make a difference in your case, but it is pretty easy to do, so I'd certainly try it.
You seem to have two different problems
Focus problem:
* Make sure that the focusing point in the cameras viewfinder is placed on the place you want to be in focus.
* Make sure that the AE-L/AF-L button is set to lock the auto-focus of the lens when pushed (look on page 135 of your user manual). The setting may have to be changed in your cameras menu
* Make sure that when you say blurry, you mean out of focus. Blur is caused by either camera of subject movement during the exposure if the shutter speed not set high enough.
Bottom half of your image being black.
This is caused when using your flash and using a shutter speed higher than the flash sync speed of 1/200th second. When using flash, it is important to use either the manual or shutter priority mode and keep the shutter speed set at 1/200th or lower
If you try all the above solutions and your camera is still not working correctly, you may need to send it to Nikon or repair (best option) or to a local repair shop.