What is it, exactly, that happens inside your camera just after you take a photograph? Well it depends of course if you are shooting JPEG files or RAW files. All digital SLR cameras (and some point and shoots) are capable of taking two image formats – JPEG which is the indsutry standard and universally readable image format, but also what we call a proprietary RAW file which contains a great deal more of image data and information for performing editing operations to the image later on.
The JPEG Scoop
If you shoot JPEG, the camera performs processing to the image before your end result is written to your memory card. In addition to just reading the exposure of the scene and determining the proper settings, post-capture, the camera renders certain parameters of the image based on what shooting mode you might have been in, or options you have set in the camera. The in-camera processing includes adjusting white balance, adjusting contrast, saturation and sharpness in the image and lastly, the JPEG file becomes compressed meaning: whatever information the camera decides is no longer necessary, it throws out.
The Trouble with JPG is…
- Each time you open, modify, then save again, you are throwing away image data as the JPEG will re-compress itself
- JPEG files reflect a one-time interpretation of your subject based on your camera’s current settings
- Attempting to make alterations later on end up being less than ideal
- A JPEG file is what we call a ‘finished image’
What is RAW?
- A RAW file is not a picture – it is a piece of data
- A RAW file is proprietary to the camera it was generated by
- It is uninterpreted and unaltered data
- Captures ALL shooting data, even beyond the camera’s current settings
Why RAW? Let me count the reasons…
- Images are uncompressed
- Larger color space and bit-depth collected by the camera
- More exposure control & latitude
- Highlight recovery capability
- Shadow relief capability
- Vibrance & Saturation adjustment
- Individual color channel editing
- Noise reduction
- Chromatic Aberration fix
- JPEGs capture 256 levels of information vs. a RAW file that contains 65,536 levels of information. (JPEG files are essentially, the square root of RAW files)
If it was your vacation of a lifetime which file format would you rather have? The one with more information, or the one with limited and crippled information? Join me again next week when I dig deeper in RAW theory and and also discuss software solutions for dealing with RAW files as well. We’ve only hit the tip of the iceberg with respect to information and all the wonderful things that can be done with a RAW file.