Photography is a medium of formidable contradictions. It is both ridiculously easy and almost impossibly difficult. It is easy because its technical rudiments can readily be mastered by anyone with a few simple instructions. It is difficult because, while the artist working in any other medium begins with a blank surface and gradually brings his conception into being, the photographer is the only image maker who begins with the picture completed. His emotions, his knowledge, and his native talent are brought into focus and fixed beyond recall the moment the shutter of his camera has closed. – Edward Steichen
Film negatives or digital negatives (RAW files) are comparable to a composer's music score, and the prints or digital outputs to its performance. Each performance can be interpreted in subtle or dramatic ways, depending on the artist.
With the digital image, this performance happens in a digital image editing program of which Photoshop is the best known. It was originally designed as a professional editing program for photographers to make the transition from analogue (the darkroom) to digital image production (the digital darkroom) and the program’s terminology and language originate straight from the darkroom. In fact, that is what the program is all about: it replicates what a skilled darkroom technician could do – think of Frank Hurley and his composite images of World War 1.
At the outset of digital photography, Photoshop was the only real choice for professional photographers. Now there are many other programs available, including Lightroom, Aperture, Photoshop Elements and iPhoto.
These have taken a large share of the market and are well suited to the production of multiple files or the creation of catalogues and archives. Simplified basic editing tools, aimed mainly at the consumer rather than professional market, can be obtained with the purchase of your digital camera, downloaded from the web for free or purchased cheaply.