More About Post-Production Processing
Before getting into post-production processing it is important to know a bit about your photograph since the way the photo was taken can affect how much enhancement can be obtained.
Photos are generally stored in two formats: Jpeg and RAW. A photo shot in RAW has many more options for enhancement than the same photo shot in Jpeg. Here’s why.
When the shutter to your camera is open the light / image that is received by the camera’s sensor is stored but when storing as a Jpeg photo the light is first compressed to the Jpeg format. During that compression process (from raw light to a Jpeg format) your camera’s software will made decisions about the image and will store the image according to those decisions. Your ability to change some of the camera’s decisions is restricted simply because you no longer have all of the light (the RAW image) from which to work but instead you have a rendering (a compressed version) of the RAW image. Cameras such as GoPro and SeaLife save the photos as Jpeg images. The advantage of Jpeg images is that they are generally smaller files so they will store faster onto the memory card and will take up less space. Jpeg format is also readable by almost all computers. The downside of Jpeg images is that because they are smaller, compressed files they don’t have all the data/image that results in a lower quality picture. In addition, a Jpeg photo will generally be stored with 256 color capability.
As you just read, the alternative storing solution is to save the light just as it was captured (in the RAW format). Often a RAW “as shot” image can be opened (using software such as Lightroom) to get to the light that was captured. Working on a RAW image gives the photographer many more opportunities to fix or enhance their image. Generally higher-end compact digital cameras are the starting point for cameras that shoot in RAW. Sony, Canon, Olympus, Nikon and others make high quality compact digital cameras that have waterproof housings available from either the manufacturer or a third party. It is important to note that while most Jpeg images will be less than 2 megs in size, it is not uncommon for a RAW image to be 20 megs in size. All this means to a photographer is that a larger and faster memory card (at least 8 gigs and no slower than Class 8) is needed. At least 300 RAW images will fit on an 8-gig card and that should get most recreational divers through a full day of diving. (You should always copy your images to a more secure source at the end of every day of diving.) An additional downside to RAW images is that your computer generally cannot process them and you need to use special software (i.e., Lightroom) to process the photos. RAW images are usually stored in a camera’s proprietary format such as .CR2 for Canon or .ARW for Sony. But one of the real advantages of a RAW image is that instead of being limited to 256 colors in Jpeg, a RAW image will have at least 4,000 colors and possibly as many as 64,000 color options to work with. This is a HUGE advantage.