File formats are simply the ways a digital camera stores information captured by a photo sensor. Digital cameras utilize sensors to store information on wavelengths of light that reach the sensor. Two primary formats used by digital cameras are JPEG and RAW.
JPEG is a compressed format (technically a compression more than a format). This means that it removes redundant data to make a file size smaller. The image is reconstructed when it is opened. The quality depends on the amount of compression. In a JPEG file, “areas of the same color will compress much better (and with equal quality) compared to another scene with lots of small detail” (Sheppard, 44).
RAW is “a file of unconstructed image data with minimal processing, and must be put into a special image converter to put it together as a photo” (Sheppard, 43).
Shooting in RAW and JPEG both have advantages.
1) Smaller file size allows you to take more pictures and store more pictures with few drives/cards.
2) “Camera manufacturers worked hard to create internal processing of JPEG files so it looks good” (Sheppard, 45).
3) 8-bit JPEG (common) allow for 256 tones in each color channel
4) Automatic processing of each picture after you shoot
1) Minimal processing of picture (is your ghost an artifact of compression and color guessing?)
2) More possibilities for adjusting picture
3) Easier to fix over-exposure & white balance issues
4) 12-bit 4000 tones per color channel 16-bit files allow for 65,000 tones per color channel
5) RAW gives more details for very dark and very light areas (since there is less compression / pixel approximation)
Ultimately, the choice for formats will be left up to the teams based on needs, economics, and personal preferences.
Sheppard, R. (2008). Kodak guide to digital photography. New York: Lark Books.