Using Manual Mode with a DSLR
One topic many photographers find confusing is how to work in manual mode on a digital SLR camera. Let's demystify it:
1. Turn the big knob on top of the camera to M.
2. Point the camera at your subject and press the shutter halfway down. You'll see in your viewfinder if the camera thinks you are underexposing or overexposing -- there's a little indicator that will let you know. (Your camera may have a little triangle, or a light or another indicator that tells you if it thinks you are over or under on your exposure.)
3. Your camera will either have two wheels -- one in front for your index finger and one on the back for your thumb -- or just a single wheel.
3a. If you have two wheels, turn one of them and notice if it is changing your shutter speed or aperture. Then turn the other. Now you know the two elements you are controlling in manual mode (you've already set your ISO setting).
3b. If you have one wheel on your camera, turn it and see if you are adjusting shutter speed or aperture. On most cameras, you then press and hold the "+/-" button (Canon) or the Exposure Compensation button "AE-L" (Nikon) and that will allow the wheel to adjust the other element. In other words, if you turn the wheel and it changes shutter speed, press the "+/-" button (Canon) or the Exposure Compensation button "AE-L" (Nikon) and now the wheel will adjust your aperture setting.
4. Adjust aperture or shutter speed until your camera's indicator is in the middle (or at zero).
5. Take the shot.
6. Then look on your viewscreen, and see if you've got it right.