Once detectives have determined the crime scene boundaries and taken whatever notes they need, then photographers document the scene.  They tend to follow certain protocol:

1. They use both black and white, and various types of color print film  (some may use digital cameras for ready access to computer enhancement).
2. They use cameras with different types of lenses, both normal and wide angle, as well as lenses for close-up work.
3. They bring separate extension flashes or other types of supplementary lighting to “paint” a crime scene with light for better detail.
4. They bring a tripod to keep shots steady.
5. They use a photograph log to keep track.
6. They include different types of scales for accurately measuring things like shoe imprints.

LAPD crime scene photographer (AP)

The procedure for a crime scene photographer is to first walk through the scene to get perspective (taking care not to move, touch, or step on anything).  They then discuss with the investigating officers (or technicians) what needs to be photographed in detail, because photographs need to be taken before evidence is moved or collected.

John Kennedy's autopsy notes (CORBIS)

The first photographs should provide an overview of as much of the scene as possible, from several different angles, to show the scene as the photographer saw it when he first entered.  In a room, for example, the photographer should take pictures from each corner.  Notes that link important details with photograph numbers should be made.  (FBI photographers blew it with the autopsy of President John F. Kennedy.  No notes were made, so it was impossible to distinguish exit from entrance wounds, and the photos were too blurry to see much detail.)

It's also important to take photos of the entire building, if the crime occurred within, and take photos of any entrance into the crime scene.  The overview photos need to include the position of any items considered to be evidence, such as weapons, bodies, or discarded clothing.

Then mid-range photos are taken, focusing on the position of items considered as evidence.  This simply provides a closer image of them in context. 

Finally, each item of evidence is photographed in close-up detail.  Written records are especially important at this stage, and if the scene is videotaped, then the photographer can describe things for the audio

To get good detail, photographers have to keep four things in mind:

1. Set the camera for the correct exposure, with a way to record any evidence that may be in shadows
2. Achieve the maximum depth of field possible.
3. Get good perspective without distortions
4. Achieve a sharp focus for best detail