The PADI Program
Realizing that no one was helping divers with post-production processing, ScubaBob decided to develop a course that would teach that material. The PADI Digital Underwater Photography Post-Production Diver specialty course was born. The below information will provide you with the theory of and some content from the PADI course.
As stated earlier, a good photograph is a multi-step process for underwater photographers. The first step is actually taking a good photo--one that is not overly blurred or extremely incorrectly exposed. There is no software that will really "fix" a blurred or seriously improperly exposed photo. Assuming you took a decent photo then you are ready for the second step: enhancing or "fixing" the photo. Enhancing your photo can allow you to improve or correct the white balance, adjust the hue, tint and exposure plus off you a host of other enhancements to make your photo come alive.
Step 1: Taking a Good Photo
As you have probably learned, taking underwater photographs is considerably more difficult than most "on land" photography sessions. For many terrestrial situations either you or the subject of the photo are not moving and often both of you are stopped and stable. Unless you are secured to a weight in an environment with no current it is almost impossible to find conditions when diving that remotely approximate the relative ease of land photography. In addition, as we descend we lose both color and light requiring divers to approximate natural life with strobes, flashes and camera settings. Again, land based photography rarely has these extreme influences by nature.
Step 2: 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 enhancements 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 stored 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 make decisions about the image and will store the image according to the rules governing those decisions. Your ability to change some of the camera's decision-making algorithms 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 advantages of Jpeg images is that they are generally smaller files so they will store faster onto the memory card, will take less space on the card and are easier to email to others. Jpeg format is also readable by most computers, tablets, pads and smartphones. The downside of Jpeg images is that because they are smaller, compressed files they don't have all the data/image and this results in a lower quality photo. 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 "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-and compact digital cameras are the starting point for cameras that shoot in RAW. Sony, Canon, Olympus, Nikon and others make 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 two megs in size, it is not uncommon for RAW images to be 20 megs in size. All this means to the photographer is that a larger and faster memory card (at least eight 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 as in JPEG, a RAW image will have at least 4000 colors and possibly as many as 64,000 color options to work with. This is a HUGE advantage.
What can I do with Lightroom?
A lot! As mentioned earlier, a Raw image can have the white balance reset to a variety of options such as Daylight, Cloudy, Tungsten, Florescent, Flash or Shade. (JPEG images usually only offered two choices: as shot and custom where "custom" gives you just a few tweaking options.) With Lightroom you can adjust the Temperature, Tint, Exposure, Contrast, Highlights, Clarity, Vibrance, Hue, Saturation, etc. You also have standard photo enhancement features such as Cropping, Redeye Removal and Spot Removal as well as some really neat features such as Graduated Filters. One of the features that is most helpful in Lightroom is a "before and after" split screen. As shown in the below photos, the split screen really shows what Lightroom can do for your photos.
The important thing to remember about light room is that Lightroom NEVER alters your original image. Lightroom imports information about your photo and then maintains a record of the changes you made to the photo without ever changing the photo it self. Lightroom is a database of photo information but does not actually contain your photos. This means that it at any time during your enhancement session, you can simply reset the image and go back to the photo "as shot" and start afresh. Lightroom only generates a photo of the enhanced image when you are satisfied with the enhancements and you export the image.