Photoshop and other software has two ways of representing images. They can be either bitmap or vector based. In fact Photoshop can have both types in one file so it’s extremely useful to know the difference between the two. Even though photographs are continuous tone images, they are in fact represented by row after row of tiny squares or pixels. Whereas paths are vector based and represented by mathematically prescribed lines.
Being able to select well, is almost as important to a digital photographer as being able to shoot well. A ‘big call’ I know, but much of the craft of seamless editing is based on the quality of the selections you make at the beginning of the process.
Most photographers move the sliders in Levels or reshape the line in Curves when wanting to adjust the brightness or contrast in their photos, but both features also contain a set of Eyedroppers which can be used to accurately place the tones in your photo.
Photoshop.com now works with your mobile phone. Okay, so we are not talking about the full version of the program being magically shrunk to fit on you cell phone, but the new free application available for iPhone, Windows Mobile, and Android based phones does bring Adobe's imaging credentials to the handheld device market.