So you read all about ISO, Aperture, and Shutter Speed. Good, now here's what you probably need to do now, and I know this is going to sound odd. Go back to the beginning and read them all again. Why?
If there is even the slightest fuzziness in your mind over how the three factors affect each other then further study and reading might be needed.
Ask yourself these questions.
If I move my ISO from 200 to 800, what happens to my shutter speed? What happens to the quality of my photograph?
If I change my Aperture from 5.6 to 2.8 what will happen to my shutter speed? What if my shutter speed is still too low to get a sharp picture? Should I do some thing about my ISO, and if so, what?
I am trying to photograph a football game, my shutter is at 1/60 of a second and everyone running is blurry, what should I do to my shutter speed? What might I need to do to my Aperture to achieve this? Might I need to change my ISO too? If so should it be higher or lower?
Those are some of the kinds of questions that illustrate the interrelationship of those three factors. If you don't know how to answer those questions, then reading the others again might help. Reading the ISO post will probably be much more enlightening knowing what you do now about Aperture and Shutter Speed. The same goes for the other two. You might find a few light bulbs turning on.
If my explanations aren't quite doing it, and don't worry my ego won't be too badly bruised, you might try some of these web sites for a fresh point of view on things.
Keep in mind that when I explained Aperture I deliberately left out things like why Aperture is numbered the way it is and depth of field for simplicity's sake. Those things aren't what is essential to the interrelationship of the three factors and can be discussed at a later time.
Don't be put off by the title of the blog, this is a good link to another explanation of all three.
The thing to keep in mind is that just like your coach, or your math teacher or any one of them might tell you, the basics, the fundamentals, are crucial to being able to genuinely understand the rest of it.
So make sure to understand what we've talked about, and come back for the next post about Point and Shoot camera modes.
We'll learn to decipher what your camera's manual is really talking about when it describes portrait mode and fireworks mode and all of that, and use that knowledge to get the most out of your camera.
For you DSLR users, many of you have some of the same modes, I know my D50 does, but it also has modes like Shutter and Aperture priority, that make knowing these fundamentals, if anything, even more important.