I have a photograph of an Allen's Hummingbird. This little guy would let you walk right up to him and photograph him. He was not shy or get bothered with a large lens rather close to him.
This is the uncroped image of the Allen's Hummingbird
So here I cropped the image. Notice the Hummingbird
is not in the center of the image anymore.
The eyes are closer to the upper edge and
makes your eyes move around the image
The twigs is a natural entry and exit point
for the image without being distracting.
Here is the same image with a more extreme
crop. Again noticed were the eye is placed within
the image. Eyes are usually (but not always)
the main focus of a photograph. With the eye
being in the upper right hand corner of the image
it makes it a bit more interesting. They call this
cutting an image into thirds. If you draw two line
horizontally and two lines vertically then you
get an image that is broken up and you can
then place the important parts of the image into the
different sections to give the image more interst.
Tomorrow I will draw the lines and we can take the image above and play around with were we put his eye and then you can start to see how this can change the way a photograph looks. The first image has a more snap shot look and feel. That is how nature photography is sometimes. You are hanging on the side of a hill and could possibly go into the river so you take a few snap shots and then crop the image later. This has been done for a long time. The y did it with film (I don't know if they did cropping with glass plate or not). You can do this with your images and see which one you like best.
I will then talk about highlights and darks. The image above has a few areas that are a bit blown out (the whites are too white to show any detail. We always want detail in the whites and the darks (or we are going for a certain look) So much to talk about.