Macro - a lens that allows you to shoot at a 1:1 ratio or greater
Close-Up - a photograph that shows all or part of a subject.
The reason I'm starting this post with definitions is because the terms Macro and Close-Up overlap and tend to be used interchangeably.
For instance, this is an image of a butterfly that is the size of my thumbnail, but was taken with a telephoto lens. Many people might incorrectly call it a macro shot since it shows the butterfly larger than life.
On the other hand, this image was taken with a macro lens, but it shows a full flower:
Now, you may notice that I titled this post "Extreme Close-Up". I'm using that term for those images that had to be taken with a macro lens because they show a subject at much greater than a 1:1 ratio. In this type of photo, the subject becomes much more abstract and revealing of the structure and patterns that make it up. For instance, consider this self-portrait (or is it a landscape).
I was quite surprised the first time I tried something like this and discovered just how reflective the eye is (can you see the camera's reflection).
Extreme close-ups are especially fun with flowers because of the colors and textures that you can highlight when you look really closely at them. This first flower becomes other worldly. The second is a play of shapes and colors.
So, that leaves us with the technical question: How do I go about capturing an image like this? There are several key features you need.
1. You probably need a macro lens. These are subject that you need to be able to focus on from a very close distance (sometimes less than 6 inches). While extension tubes can be used, a macro lens is much more flexible and better quality. [Note: Extension tubes are empty rings that sit between a lens and the camera, thereby shifting the area of focus much closer. However, they will also lose you several stops of light and can be very tricky to get to focus correctly).
2. You need a tripod. The close you are to a subject, the more obvious any movement becomes. You need a tripod to remove any slight jitters you may cause from the equations. A remote release might also help, but something similar can be attained by using the timer.
3. The closer you are to a subject, the smaller the slice of the image that will be in focus. You want the most depth of field you can get. f22 is a good place to start. At the same time, try to make your camera as square to the subject as possible. The flatter the focal plane, the more apparent depth you get.
4. Depending on how comfortable you are working with your processing software, experiment with focus stacking. This is a process that lets you combine multiple photos of the same subject into a single image. In this case, you take a shot that keeps the closes part of your subject in focus and then change the focus so a part just behind that is good, and then repeat until you have photos of the entire subject in focus. I believe some cameras can do this for you automatically, so check you manual.
I hope you can get out and play with some subjects this winter. It's fun and keeps you active.