>I found out that pictures taken by my camera are >totally/almost in black when I use the manual setting. I took >the pictures under bright fluorescent light in a room at >shuttle speed of 200 and ISO 100. The camera works perfectly >if it is under auto setting. > >I may have messed up some features. Any idea where to begin >with?
I think that the first thing to do is to pay attention to the camera. In Auto mode, make a photo then review it and make a mental note of the exposure: shutter speed (S), aperture (A), ISO, exposure compensation (eV). Switch to M (manual) mode, set the camera to exactly the same settings as the shot made in Auto mode. Focus on the same point on the subject and at the same focal length/zoom setting while standing in the same spot. Take the same photo, then compare the two. Most of the time they'll be identical or very similar (aws long as the light doesn't change between shots.
Then experiment by increasing or decreasing the Aperture by a couple of stops. Take the same shot and compare to observe the differences. Then change the shutter speed, take the same shot and do another comparison. Repeat the process changing ISO and then changing eV settings. If you get confused, simply set the D7000 to Auto mode or P mode again to make another shot and note the exposure settings.
Rely on the camera's excellent built-in meter to provide the information you need to then tweak manual exposure to your liking. Do this sort of thing for a few weeks and you'll soon begin to get an intuitive sense of which settings work best in a wide range of lighting and for a wide range of subjects.