Digital Camera File Formats

In digital photography there are many types of formats to save, open and edit images. On one hand the uncompressed formats (RAW, TIFF and others) occupy a lot of space in the cameras memory but offer an excellent quality that doesn't deteriorate when modified and saved over and over; files in TIFF format and others admit a certain amount of compression without loss, although this option is usually not available on the camera and can only be used on the computer. On the other hand there is the compressed format JPEG, which saves a lot of space in the memory with a reduction of image quality when modified and resaved. It's possible to pass from one format to another with an image editing program: directly changing the original image or making a copy and saving it in the new format.

The uncompressed formats are adequate for maximum quality work (are used in graphic art digital scanners for printing). The uncompressed format -or compressed without loss- is comparable to the original slide or negative: it is the source of successive copies and versions, in dimensions or resolution, mode, depth of color or format. Unless we have a shortage of memory -something that happens frequently in a camera- TIFF format is ideal to create an image file, with a camera or a scanner. Afterwards, with the image

editor, we will be able to make the necessary corrections (trim, retouch, adjust brightness and contrast or color balance levels, to mention the most frequent), because if we saved the image in JPEG format in the first place, after the corrections we will have to save it again giving place to a new compression with loss of quality. If the file was originally created in JPEG format -for example, because we don't have enough memory in the camera or we didn't have the option- it's convenient to convert it to a format without loss before retouching it, which assures that the image quality will not be reduced when modified and resaved.

The compressed JPEG format is the most widely used because of it's space saving, as long as the images saved in this formats are destined to be viewed ( opened and closed ) and not be edited ( opened and saved ). Therefore, we can make a more compressed version of the image when, after one or more editing sessions, we have achieved a final version of the image. JPEG format offers different degrees of compression; low compression equals a higher quality and high compression means an important loss of detail. Normally cameras offer the possibility of storing in maximum quality and the image editing programs can compress the original file in a much greater degree. To have an idea of the compression effects, have a 8 MB size in TIFF format, converted to maximum quality JPEG stays saved with a file size of 2.4 MB (1/3 of the uncompressed size) and of only 80 KB in maximum compression JPEG (1/100 the original). The JPEG format is the standard for web page photographs and is very recommendable for sending images by e-mail (unless they are destined to a high quality print) because it allows a high load and download speed.