Police Photography: Essentials of Photography

Exposure

• Exposure is the amount of light received by a photographic emulsion or imaging chip.
• It is the product of the intensity of the light, the aperture size, and the shutter speed.
• A properly exposed photo is neither too light nor too dark.
• Exposure controls include shutter speed control and lens opening.
• Shutter speed control determines the length of time that the film is exposed to light.
• Lens opening (aperture) controls the amount of light that reaches the film.
• A small "f" number indicates a larger lens opening, while a large "f" number indicates a smaller lens opening.

Available Light Photography

• To obtain proper exposure using available light, set the ASA or ISO dial according to the film speed.
• Set the shutter speed to 1/125 sec as a starting point.
• Adjust the aperture ring to line up the light meter needle in the viewfinder.
• Use a shutter speed faster than 1/30 of a second for handheld photographs.
• Support the camera with a tripod for shutter speeds of 1/30 of a second or slower.

Exposure Using Flash (Artificial Light)

• Adjust the flash unit to the proper ASA/ISO setting according to the film speed.
• Use the automatic settings on the flash unit, indicated by color codes.
• The color codes indicate the maximum distance capability and required lens aperture setting.
• Adjust the Thyristor Sensor on the front of the flash to correspond to the chosen setting.
• Consider the distance requirement and desired depth of field when choosing a setting.

Focus

• Focus is the physical point at which rays of light converge to form a properly defined image of the subject.
• Sharp images are important in crime scene photography to provide clear evidence.
• Consider the focal point and depth of field when taking close-up photographs.
• Use a tripod to ensure a sharp image in close-up photography.

Depth of Field

• Depth of field is the distance measured from the nearest to the farthest object in apparent sharp focus.
• It is also known as the zone of focus.
• Depth of field is not the same as sharpness in front and at the back of the subject.
• To get depth, use a small lens with a large "f" number.
• Increasing depth can be accomplished by moving further away from the subject or setting the aperture to a higher number.
• However, moving away from the subject can distort the image, and setting the aperture to a higher number requires adjusting the shutter speed.
• Telephoto lenses have less depth than normal lenses.

Police Photography: Depth and Exposure

Depth

• Depth refers to the distance from which a photographer can maintain a sharp image of the subject.
• To achieve depth, use a small lens with a large "f" number.
• Increasing depth can be achieved by moving further away from the subject, but this can distort the image.
• A more effective way to change depth is to set the aperture to a higher number, but adjust the shutter speed accordingly.
• Using a small aperture (high "f" number) can keep the picture sharp, especially when depth is essential.

Moving Subjects

• When photographing a moving subject, use a fast shutter speed to stop the action.
• Moving away from the subject can increase depth, but telephoto lenses have less depth and cannot achieve depth by moving back.

Focus

• To ensure sharp images, find a focal point that can serve as a visual reference point in court.
• The tripod is used for close-up photography to concentrate on the most important part of the image.
• The sharp area of the photograph extends about one-third in front and two-thirds beyond the subject.

Type of Lens

• Different lenses can be used to highlight specific parts of the image (e.g., wide-angle lenses make objects look smaller and distances appear greater).
• Zoom lenses can be adjusted to acquire a close-up photograph from a distance.

Depth of Field

• Depth of field is the distance between the nearest and farthest objects in apparent sharp focus when the lens is set to a particular distance.
• Depth of field is often misunderstood as the sharpness in front and at the back of the subject.
• The term "depth of field" is also known as the "zone of focus".

Exposure

• Exposure is the amount of light received by a photographic emulsion or imaging chip.
• Proper exposure is the product of light intensity, aperture size, and shutter speed.
• A properly exposed photo is neither too light nor too dark, while an incorrectly exposed photo has details hidden by dark shadows or washed out by overexposure.

Exposure Controls

• Shutter speed control determines the length of time the film is exposed to light.
• Lens opening (aperture) controls the amount of light that reaches the film, with a smaller "f" number indicating a smaller opening and vice versa.

This quiz covers the fundamental concepts of photography, including exposure, aperture, and shutter speed. Familiarize yourself with the basics of photography as applied to police work.