You point your new digital single lens reflex camera (dSLR) at your subject.
You gently squeeze the shutter release. The camera locks in the focus, takes a meter reading and then waits. You see the perfect moment, you squeeze the shutter release the rest of the way, the camera takes a final meter reading, the mirror flips up, the shutter opens, light hits the sensor, time passes, the shutter closes, the mirror returns to the down position, the camera “develops” the image into a jpg. Done. Let’s check the display and see what we got…
Many people I know have been stepping up to a dSLR, or have decided to learn how their point and shoot or super-zoom hybrid cameras actually work. Why? To take better pictures. To take pictures that are in focus and that are properly exposed.
Camera manuals from the manufacturers are ridiculous. For example, find the ISO control on your camera, look up ISO in your manual, and you'll see something like... “This control is used to adjust ISO. You can set the ISO from 100 to 6400. To lower ISO, turn counter clockwise, to raise ISO, turn clockwise.” Well that explains it all perfectly, right? Wrong!
Books on photography abound. They will teach you everything you want to know and more about exposure, color balance, ISO, etc. But they are big and long and really, do you need or want to know how a sensor is designed, how it is made, and how it works? Maybe. But to be able to quickly get using your camera with great results, knowing a bit about how and why you got great results, and to be able to repeat great results - for this, these books are too much.