With the number of megapixels in today’s cameras, there can be quite a bit of information for the camera to process when you take a photograph. The more information in the file, the bigger it will be and the more room it will take up on the memory card. To avoid filling it up too quickly, most file types "compress" the information so each image takes up less space.
The method of compression will either be "lossy", where some information is lost during the save in order to make it smaller, or "lossless", where the save file looks for ways to most accurately retain all the detail in the image.
While losing some detail in your images sounds bad, lossy file types tend to be smaller and save faster, which means you can take more photos in a shorter amount of time. In addition, many users find the amount of detail lost in some of these formats is very small and hardly noticeable, especially for home use.
Your camera will support at least some of the formats below, and maybe more. The user manual will show you how to set the camera up to use them.
- RAW files are very common on DSLR cameras and give a lossless image that is pretty much unaltered and uncompressed. These can be very large files that take a while to save. RAW files are versatile as they store so much information from the camera, which makes them popular with professionals and serious enthusiasts. They can be difficult to work with, as they may need special software on your computer in order to be processed and used.
- TIFF files can be lossless or lossy, and tend to be quite large. This can slow the camera down when taking photos in rapid succession. Like RAW files, these are very good for the more serious users who will edit and enhance them on their computer, and the larger file size allows more detail and colour to be saved in the images.
- JPG is one of the most widely used file formats. Although this is a lossy format, the amount of detail retained and small file size make it very useful. JPGs save quickly, often letting the camera take photos at the highest speed possible. Most home and office computers will have software that allows you to view JPGs, and the file size is small enough so you can fit several in an email. There is some reduction in image quality compared to TIFF and RAW, but at lower compression levels many users find this hardly noticeable. Your camera may have different JPG compression settings, so check the user manual to find the optimal one for you.
The number of images you can store on your camera's memory card will be determined by the file format and digital image’s resolution. the table below is based on a 10 megapixel camera:
Knowing the main types of file should save you some trouble.
Always refer to the manufacturer’s manual for specific details.