An online book of Common Sense Photography, by Rhett Stuart

Should I Use jpeg or raw or dng as My File Format?


The main issue for me is: Will I be able to access my own photographs 20 years from now? By using a widely used format the chances are there will still be software and equipment around to pull those jpeg’s off that old gold CD.

Most digital cameras use jpeg or jpg as the file format to save your digital images on the computer. There are newer and technically better formats out there but they are not widely used. Jpeg can later be saved as a tiff or gif image in web site use. Jpeg is compatible with all consumer photography software. Jpeg condenses the file size down so more pictures can fit on the memory card. Jpeg’s are getting better and better with new in-camera processing so there is less of a difference between jpeg and raw with each generation of digital cameras.

The advantage of saving images in the raw format is the exposure can be lightened later on the computer. Raw resembles a film negative (analog). A jpeg condenses the file down and it just records a dark area where the shadows are. The raw format records hidden areas in the shadows and highlights that can be revealed by lightening or darkening them later in Photoshop®. The disadvantage of raw is a raw converter is needed to view it, and a raw image doesn’t look nearly as good as a jpeg right out of the camera. You have to process it. Photoshop® supports most raw formats, even on new camera models. After you process the raw image, you can save it to jpeg.

Dng is a new format similar to raw that Adobe is supporting, and resembles a digital negative like raw. It is similar to raw but the advantage is any camera that will use dng can be recognized by any software that supports dng. The dng format would be the same for any camera that uses dng. Raw formats vary from camera to camera, even with the same manufacturer. Dng is not in widespread use but if it does become in widespread use, it will be better then raw because all digital cameras will now have the same “raw” type format for the digital negative.

There are many new file formats. I am going to stick mainly with jpeg until there is another format that is in wide use and is clearly better then jpeg.