Image Format … What’s the difference between JPEG and RAW?
Most point and shoot cameras capture your image as a JPEG (Joint Photographic Experts Group), a very common image format. JPEGs are easy to edit and store since they are compressed. However, when you move into more professional photography, the need for unaltered images is significant. Serious photographers consider any loss of image quality or information completely unacceptable. Most DSLRs still capture photographs in JPEG and RAW formats.
JPEG
Most photographers have managed JPEGs before as they’re the most efficient image file format. Because it is a compressed or “lossy” file format, its file size is reduced, making it easier to manage in terms of disc space. What is a lossy file? A lossy file is defined as an image that has some of its data discarded so that the file size may be compressed resulting in a smaller size. The more compression that is applied, the more the image will break down in quality.
With its smaller file size, JPEGs are much easier to manipulate. JPEGs are not only supported by many software editing programs but their size makes them easier to transport and share. Downloading time is shorter while thumbnail viewing on most PCs and Macs is faster.
The result is a file that’s easy to work with but missing some vital information. The ability to edit such items as white balance, tone curve or sharpening will be hampered in its colour mode RGB.
The JPEG format is great for snapshots, quick proofs, and photography that do not require much post-production manipulation. Perfect for casual shots, JPEGs are ideal for websites and are easily transmitted over the web.
RAW
Today most professional digital photographers shoot their images in RAW format because the uncompressed file has no loss of data and can be adjusted and manipulated by the photographer, allowing greater control of the final output of their image.
RAW files are larger than JPEGs but without the compression. A RAW image takes up more space on a memory card, but because it is not converted by your computer’s processor, the file is pure and unscathed. Using the camera’s supplied RAW file conversion program or third party ones such as Capture One, you can edit your image and convert it into a RGB image in either the JPEG or TIFF format.
Because your camera’s processor is not compressing the RAW file, you have the ability to gain full control over the white balance, tone curve or sharpening of the image. RAW files are superior to JPEGs because the manipulation of the image is in the photographer’s hands. When a JPEG image is corrected, it has already been adjusted by the camera’s processor so the second time it begins to lose information or data. This results in a loss of colour gamut and bit depth.
Given the uncompressed nature of the RAW files, it goes without saying that the post-processing of these images is more time consuming. Even without editing the image itself for white balance or tonal curves, the images must at least be converted to a file format that is printable or publishable on the web. Because RAW formats are camera-specific, not every software program can support them. In addition to the camera’s conversion software or a third party that supports your camera’s RAW files, you will also require a powerful computer capable of managing the workflow.
Offering the most versatility and control, RAW file formats are ideal for professional photographers who require control over their images. The disadvantage in loss of speed and increased post-production time may not be ideal for photojournalist or sports photographers. As a compromise, there are cameras that shoot images in RAW and JPEG at the same time. The processor in the camera shoots in RAW, duplicates the file and compresses it into a JPEG.
