Here's the Reader's Digest version of the novel. ISO is the digital equivalent of ASA, or film speed. The lower the ASA the "slower" the film. This meant two things. 1. You needed more light or longer exposure times. 2. Higher quality of picture due to less "grain". In digital ISO is equal to ASA in that the lower the number the more light you need and the better quality of the image. I recommend using the lowest ISO you can to get the picture. I normally do not move away from 100. Maybe 400 for indoors without a flash. With film you could use higher ASA and not see too much grain. With digital, it seems that once you hit 600 you start getting the little off color pixels called noise. Although noise and grain are two different image defects, digital really does not have "grain" so I guess they invented "noise" to replace it. (grin) Most of your shots will not need anything more than 400 ISO. But in a nutshell if you can't get a shot because it's too dark, increase your ISO. d-lighting I have never even played with so I won't even touch it, cause I don't know what I'm talking about. White balance is what used to be color contrast in film. And in my opinion is much more critical in digital than it was in film. With film you had films designed to compensate for lighting conditions. Incandescent lights (bulbs) give a yellow tint to an image. Fluorescent and Mercury give a green tint. They developed films that would adjust for these conditions. They also developed filter (like the FLD) to compensate, or correct the tint when shooting with regular "daylight" film. Today's digital cameras have all of these films or filters built right in. And many of them have an "Auto white balance" feature that the camera can chose the best setting. When to use them? Well use the one that looks like a sun outdoors, the one that looks like a light bulb indoors, the one that looks like a fluorescent tube, indoors under fluorescent lights, and so on. Then mix and match. Try them all under the same lighting conditions to see what the result will be. One trick that photographers who used a "Western" motif was to shoot daylight film but light with incandescent light. This gave a yellow cast to the picture and made it look "old". Along with white balance you should learn about "color temperature". Color temperature is used to convey warmth or coldness. For example blue is used a lot for snow scenes. Orange is used for Beach scenes. Blue and shades of it, are associated with being cold. Oranges and reds are associated with warm or hot. Your white balance plays into this. Often, adding a specific tint to a picture can give it more meaning than what is in the image. Things you did not ask about, but are in line with lighting are shutter speed and aperture or f-stops. Shutter speed is a no brainer. That is how long the shutter stays open, and how much light reaches your image plane. For film it was film plane, for digital it is sensor plane, I combine them and call it image plane the surface of whatever is recording the image. Hand in hand with shutter speed is your f-stops. This is an opening in the camera lens that can be adjusted (aperture). The smaller the number (f-1.0) the bigger the opening, and more light that gets to the image plane. The bigger the number (f-22) the smaller the opening, and less light that gets to the image plane. Your f-stops also deal with Depth of Field (DoF), but that is a whole 'nuther subject all together. Although shutter speeds are measured in seconds, the unit of adjustment is called a stop. Rule of thumb is that if you increase your shutter speed, you need to decrease your f-stops by the same amount, and vice versa. Quick definition of a stop is that it increases, or decreased light by half. When should you use these? Depends on what you are trying to do. Are you trying to simply replicate what you see, or are you trying to set a mood as well? Outside of the obvious things like you don't want a picture of your kid's birthday to be really yellow or green, white balance is another tool of composition. How you determine when to use white balance is doing to depend on you. And knowing that is going to depend on how much you play with it. So try different setting under different lighting conditions. Even if you mess the picture up, you will learn what it does and what the result will look like. Soon it will help you trouble shoot image problems. Such as a slight green case to one side of a night shot - look for a street light that you didn't think was going to bother your picture. Search the web. There are hundreds of free information sites that you can visit and learn much more than I, or anyone can explain here. Learn, then use it. Do exactly what the lesson, or article tells you to until you understand it. Then play with it. Change the settings to see what happens. This is how you develop your skills.