Nikon D3100 won't initially focus?
Whenever I try to take a picture, it won't focus. I tried auto and manual focus- neither work. But whenever I look at the photo in the photo library, it's perfectly focused. How do I fix this?
Btw: please help me soon because I'm visiting the Mediterranean for about 2 weeks and I want to be able to take photos easily.
If the photo is focused, then your camera is obviously focusing. Look through the viewfinder and turn the little wheel right next to the viewfinder until things come into focus. Then read the instructions that came with your camera.
I guess we first have to ask if you have the following setup on your camera
* You have placed one of the focus points in the subject that needs to be in focus
* You have the auto-focus on the camera set to either single or continuous focus mode. Page 38
* You have the lens focus switch in either the "A" or "M/A" position.
* You are NOT attempting to use the camera as a P&S camera by using the live view feature on the camera, but are using the cameras viewfinder.
This is how you should be holding the camera to assure that you get sharp images, showing NO blur caused by camera movement. Page 25. Holding a camera at arm's length can only add to problems when it comes to getting good, sharp photos.
You are correct to iron out issues you have using a fully adjustable camera long before your trip.
Just owning such a camera does NOT guarantee that you will be producing brilliant images right out of the box
You have to 1) have the basic understanding of how photography works, balancing ISO, shutter speed, and lens aperture and 2) how to use the controls on the camera. This applies to ANY fully adjustable camera, Nikon, Pentax, Canon, Sony, etc.
Here is a link to help you with using the ISO, shutter speed and lens aperture to produce excellent exposures.
http://camerasim.com/apps/camera-simulator/
And here is a link to help you with your composition, tools to make your images more compelling.
http://photoinf.com/General/Robert_Berdan/Composition_and_the_Elements_of_Visual_Design.htm
Obviously try again
To add to Hondo's reply, look at page 22 in your manual. It will tell you how to adjust your diopter control. The diopter control allows you to adjust the viewfinder focus to your eyes.
Try adjusting the diopter to make sure that what the camera sees as focused is what you see as focused too. Read the manual on how to go about it.