There are several file types commonly used by photographers for digital imaging. Understanding these different file types will help you get the most out of your images and avoid the stress of “kind of knowing” what they’re for.
RAW – A RAW file is created in camera as you shoot. It is the raw data as seen by your camera sensor before it is converted into an image. Common RAW extensions are CR2 (Canon), NEF (Nikon), ARW (Sony). These files are created in camera only.
PSD – Stands for PhotoShop Document. All RAW files must be processed by an image editor. Most computers now come with software capable of processing RAW files. Photos on Apple computers is one example. As a photographer you’ll probably want more editing capabilities and will may use Lightroom, Photoshop or Capture One as your RAW processor. Once you process your file and open it in Photoshop you’ll need to save the pixels (Picture Elements) as a new type of file. PSD is a common file type used by photographers because it is uncompressed and can contain layers used for retouching and image adjustments. PSDs are usually created in Photoshop. Can also be created by other software such as Lightroom and Capture One.
TIFF – TIFF stands for Tagged Image File Format. TIFF files are also used by photographers. Like PSD’s they can contain layers and are uncompressed. Typically they are used to send to printers or others who may not have Photoshop. TIFFs are usually created in Photoshop. Can also be created by other software such as Lightroom and Capture One.
JPG – Stands for Joint Photographic Experts Group. Every photographic image you see on the web is a JPG. Usually created as the last step JPGs are compressed images with no layers. The JPG algorithm permanently removes similar color to “compress” the image file size. This is a very sophisticated process that creates images that are virtually indistinguishable from the originals and take up much less memory. Every image you put online or email to friends it will be a JPG. Converting an image to JPG permanently removes information from the image. JPGs can be created by Photoshop, Lightroom, Capture One and other photo editing software. Can also be created in camera but not recommended.