Cameras do not see the world as we do. They just use one f/stop per photo, therefore the result may be an overexposed or underexposed photo. Our eyes can perceive a scene that contains bright highlights and dark shadows as well. A good example is the night sky with the full Moon.
We are able to see easily the Moon, stars and the landscape. If we set the camera to shoot the same scene and adjust it to have a proper exposure of the Moon, the landscape will be dark. If we adjust the camera for the landscape, the Moon will look like a flash of light. The technique used extensively to overcome this barrier is HDR photography.
The idea is to combine shots taken at different exposures, trying to create a more natural view of the scene. This shot is a multi second exposure with a dslr camera on a telescope equipped with an equatorial mount. It shows the crescent Moon (the brightest part) and the rest of the Moon which is fainter. We are able to see the faint part because of the sunlight that hits the Earth and bounces back to the Moon.
This is why these shots are commonly referred to as 'earth shine' photos. This is a one shot image. It is not HDR or a composition of many photos. The only process includes saturation, contrast and sharpening adjustments. The technique I used can be described as 'waiting for the right cloud!'. The particular cloud covered just enough of the Moon's surface for just enough time to block the bright part, therefore the light that the camera recorded was relatively even.
Camera Model Canon EOS DIGITAL REBEL XTi, SW ED 80 telescope + barlow 2x, Shooting Date/Time 13/1/2013 19:32, Tv( Shutter Speed ) 10 sec, Av( Aperture Value ) 15.0, ISO Speed 400