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This story was printed from CNET Asia.
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Quick guide to digicam file formats

By Leonard Goh
22/02/2008
URL: http://asia.cnet.com/digitalliving/tips/0,3800004921,62038064,00.htm

While your camera may be able to shoot only in JPG now, you might want to consider shooting in other file formats when you decide to upgrade your camera or take your hobby to a higher level. Terms like TIFF and RAW can get confusing sometimes, so let's unravel the mystery of these file formats here.

JPEG (Joint Photographic Experts Group)

The most common among the three, JPEG is a file format that heavily compresses picture data for storage in memory media. This compression may cost you loss in image quality, but if you are looking to send or upload these files on the Web, this format is the way to go since most computers can read JPEG format files.

You may see different size options for JPEG in your camera. Canon uses "L", "M" and "S", which stands for Large, Medium and Small. Other manufacturers may use different terms for this, so check the camera's manual.

With the advent of digital camera technology (in terms of sensor size and image processing engine), the JPEG files generated after you take a picture are often good enough for normal photo print and Web. Some image-editing programs like Adobe Photoshop can even allow you to save your edited JPEG file in different compression formats.

However, one thing to note is that everytime you open a JPEG file to apply changes and save it, it will take away information. So keep the original tucked away safely somewhere.

If you have a small-capacity memory card, you'll want to shoot in JPEG format as this will let you take more shots.

Advantages:
  • Small file size
  • Different size options
  • Readable on most computers

    • Disadvantage:
  • Heavy compression applied




    • TIFF (Tagged Image File Format)

    Although this format is less commonly found in digital cameras, it is still offered in higher-end models like the Nikon D300 and certain older ones like the Olympus Camedia C-7070WZ.

    This format is slowly being dropped by camera manufacturers as it takes up a lot of space in the memory media. Compared to a JPEG file of the same pixel dimension, the TIFF file can be 10 times bigger in file size. Since the quality of JPEG images is getting better, TIFF may soon become obsolete in digital cameras.

    A redeeming factor for TIFF is that it applies lossless compression to your file when saving.Thus, you can get a richer, more detailed picture when shooting in TIFF.

    Unless you are really fussy about image details and have a high-capacity memory media, TIFF files may take up too much space for storage.

    Advantages:
  • Lossless compression
  • More detailed image

    • Disadvantage:
  • Large file size



    RAW

    Also known as a "digital negative", the RAW format was developed by camera manufacturers that realized there were still photographers out there who wanted more control on how the final picture would be.

    RAW format is often praised for having the most information to generate an image file. Just like how a photo print can be developed from a negative, a RAW file can be processed to become a digital image.

    While JPEG and TIFF may contain changes made by the camera to suit the image, a RAW file is uncooked and you can fine-tune it until the desirable result is achieved. In harsh lighting conditions, certain highlights and shadows in your image may be lost if you shoot in JPEG or TIFF. However, with RAW, if the exposure is correct you can actually retrieve these details back by making adjustments.

    RAW format are more commonly found in dSLRs, though recently it has made its way into prosumer models like the Canon PowerShot G9 and Panasonic Lumix DMC-FZ50. Although larger in file size then a JPEG, a RAW file is still considerably smaller then a TIFF.

    One thing to note is that each camera manufacturer has its own RAW format. For Canon, it is .CRW and for Nikon it is .NEF. Therefore, you will need the software supplied by them to view and edit your pictures. If you want to share these images, you'll have to "process" the RAW file to a more common file format.

    Strictly for the purist, you may find RAW daunting to handle at first, but you'll appreciate the control you have on the resulting image.

    Advantages:
  • Total control over resulting image
  • Smaller file size then TIFF

    • Disadvantage:
  • Have to process the images before it can be shared


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