It’s very easy to crop a digital photograph in post-processing even quite drastically these days and thanks to the camera’s sensor retain a relatively grain-free image. However, there is another positive aspect of digital photography that enables photographers to use another way to compose images in the camera.
The cost of producing a digital image is cheap compared to film. With film cameras, you have to purchase film each time you want to take pictures. You also have development costs whether from a laboratory or processing at home. With digital cameras, once you have your equipment and memory card, an image will cost you nothing. You can take as many photographs as your memory card/s and storage will hold and the cost will be zero.
When assessing a scene, therefore, instead of taking the image knowing you can crop in post-processing later, do it immediately in camera by reframing. Reframing then refers to composing, taking the picture, recomposing and taking another photograph as opposed to cropping which is a method of emphasis undertaken in post-processing after the picture is taken.
Photographers should get into the habit of taking as many images of a scene that they need, moving and reframing with each frame, recording a shift, subtle or otherwise. They should move around their environment producing variations on their original idea.
This should mean that in post-processing the need for the large cropping of an image is kept to a minimum and image quality, therefore, to a maximum