In order to achieve the best crop for any space we photograph, whilst composing shots on site or when editing in the studio, we firstly need to know the desired aspect ratio. The aspect ratio is essentially the size (width x height) of the final image. The aspect ratio can vary depending on the image application, for instance if the image is intended for a double page spread in a magazine the aspect ratio will be the full width of the double page plus the height of the page. If the images are intended for a website with a fixed viewing window, the aspect ratio will be determined by the width and height of that specific viewing window.
Above are some examples of typical aspect ratios. These examples are industry standard however, bespoke aspect ratios are also very common….
… like the example image above from the ZAC and ZAC website homepage, which has an aspect ratio of 3174 x 1109.