Police Photography Chapter 8 PDF

MODULE POLICE PHOTOGRAPHY CHAPTER 8: ESSENTIALS OF PHOTOGRAPHY OBJECTIVES: a. Familiarize with the various essentials of photography EXPOSURE Exposure is define...

MODULE POLICE PHOTOGRAPHY CHAPTER 8: ESSENTIALS OF PHOTOGRAPHY OBJECTIVES: a. Familiarize with the various essentials of photography EXPOSURE Exposure is defined as the amount of light received by a photographic emulsion or imaging chip. Overall exposure is the product of the intensity of the light, the aperture size, and the shutter speed (Hedgecoe, 2005). A properly exposed photo is neither too light nor too dark. On the other hand, in incorrectly exposed photos, the details are hidden by dark shadows or washed out by being overexposed. The photographer must always remember that a camera makes adjustments to light much like the human eye. You might say that the eye has a built-in light meter. That same light meter is imperative for getting usable shots with camera. A light “meter” will tell the photographer what camera settings will give the best results. Exposure Controls Below are two adjustments in the camera that can control the amount of light that reaches the film. 1. Shutter Speed Control The shutter speed control determines the length of time that the film is exposed to light. The numbers found on the control correspond to fractions of a second. 2. Lens Opening The size of the lens opening in your camera is the other factor that determines the amount of light that reaches the film. The indicator on the camera for the degree of light passing through the camera lens is called the “” number. The smaller the “1” number, the smaller the opening and vice versa. Much like fast films and slow films, there are fast and slow lenses. A fast lens, for instance, is one that transmits a lot of light. The user should be cautious, however, since fast lenses do not produce the sharpest images. 1|Page  MODULE POLICE PHOTOGRAPHY Available Light Photography Below are steps to obtain proper exposure using available light (no flash): 1. When inserting a roll of film in the camera, always set your ASA or ISO dial according to the film speed as stated on the film cartridge. This adjusts the built-in light meter to the film’s light sensitivity. 2. For crime or accident scenes, the shutter speed on the camera should be set at 1/125 sec. This is usually a good starting point for the shutter speed. Your shutter speed could change from a slower speed to a faster one depending on the light intensity at the time the photograph is taken. 3. Adjust the light meter needle as seen in the viewfinder by turning the aperture ring located on the barrel of the lens until the needle is properly lined up. When the needle is properly lined this tells the photographer that the light entering the camera will produce a properly exposed photograph. 4. Use a shutter speed faster than 1/30 of a second for all handheld photographs. The camera must be supported (such as through a tripod) for shutter speeds of 1/30 of a second or slower. 5. The final step in available light photography is to compose your shots and focus. Exposure Using Flash (Artificial Light) Your flash will be so important to you that it deserves special consideration. The flash is your light. It is with you at all times. You can, therefore, learn to control it more predictably than you can the available light that you happen to find on the spot. With experience, you may be able to learn to use the flash to duplicate almost any type of natural lighting. Even without experience, the flash can help improve crime scene photography a great deal. You normally need front lighting and the flash mounted on the camera will provide that automatically Below are steps to follow to obtain properly exposed photographs in artificial light, i.e., using flash. Note that when using a flash as the light source, adjustment must be done to both the camera and the flash unit in order to obtain a properly exposed photograph. 2|Page  MODULE POLICE PHOTOGRAPHY 1. Your flash unit, now being your main light source, must be adjusted to the proper ASA/ISO setting according to the speed of the film being used for the same reasons you adjusted the camera light meter to the film speed being used. 2. The Vivitar 283, a popular flash unit with removable sensor, has four automatic settings as well as a manual mode. 3. These automatic settings are indicated via color codes (yellow, red, blue, mauve) on the flash scale dial on the side of the flash unit. These color codes will indicate the maximum distance capability as well as the required corresponding “T” stop (lens aperture setting). 4. Once you have decided on the most appropriate setting, note the color. You must now adjust the Thyristor Sensor on the front of the flash so that the color code on it corresponds to the one on the flash scale. 5. When choosing a setting you must keep in mind both the distance requirement and the desired depth of field (DOF). That is, color code yellow used to shoot objects about 40 feet away requires f/2.8, but there is little DOF. Color code mauve which requires an f/stop setting of f/11 will give you the greatest DOF, but the light from the flash will only properly expose objects up to ten feet. You will have to come to some sort of compromise here. 6. When using the manual mode, always ensure your aperture setting corresponds with the distance indicated on your flash scale. Also, check the Thyristor Sensor to ensure that you have set it “M” position. FOCUS Focus is defined as the physical point at which rays of light from a lens converge to form a properly defined image of the subject. The sharpness or focus of a photograph will make a difference in a court of law. If the jury can see exactly what has taken place through a series of photographs that are clear and concise, the evidence will be much easier to understand. 3|Page  MODULE POLICE PHOTOGRAPHY Below are some thoughts to consider in ensuring the photographed images are in focus. 1. Sharp images Getting sharp images may be difficult when close-up photography is required. Although the film speed and the depth of field is not critical in a close close-up photograph, the crime scene specialist must always find a focal point that can serve as a visual reference point and be understood in court. In other words, the photographer must decide how much meaning he would lose for any particular focal choice. 2. Tripod Since the depth is so shallow, the photographer must concentrate on the most important part of the photograph. The tripod is used for a close-up photograph as described. Remember that the sharp area of the photograph extends to about one-third in front and two-thirds beyond the subject of the photograph. Also remember that the lens used has a significant effect on the way that the photograph will look when processed. 3. Type of lens Sometimes the photographer may want to highlight a particular part of the photograph. To do so may require a different lens. Wide angle lenses, for instance, make objects look smaller and distances between look greater. Conversely, zoom lenses can be adjusted to acquire a close-up photograph that can be taken from some distance DEPTH OF FIELD Depth of field is the distance measured from the nearest to the farthest object in apparent sharp focus when the lens is set or focused on particular distance. The term, also known as the zone of focus, is used to describe how much of what the camera sees in focus, Depth of field is usually misunderstood and thought to be the sharpness in front and at the back of the subject of the photograph. The term is really used, however, to describe the distance that the investigator can move away from the subject and still maintain a sharp image. Depth is the area in front and at the back of the photograph 4|Page  MODULE POLICE PHOTOGRAPHY To get depth, remember the following: 1. Use small lens – To get depth, the photographer will use a small lens with a large “f” number. Understanding this concept will control the sharpness of every photograph. 2. Change in depth – Increasing depth can be accomplished by moving further away from the subject of the photograph, but this often distorts the photograph by changing the size of the subject’s image. A more plausible way to change depth is to set the aperture (lens opening) to a higher number. The shutter speed, however, must also be adjusted because of the corresponding light restriction that will naturally occur when going to a higher “f” number. When depth is an important element of the photograph, use the smallest aperture possible to keep the picture sharp. 3. Moving subject – When you are photographing a moving subject. A fast shutter speed will be needed to stop the action. Keep in mind that moving away from the subject of the photograph will give a greater depth. Also remember that telephoto lenses will have considerably less depth than normal lenses and you cannot move back to achieve depth. 5 Long Exposure Photography Tips https://www.youtube.com/watch?v=I6JcLKzEdsc Different FOCUS MODES explained References: https://www.youtube.com/results?search_query=focus+photography Handbook on Photography by Dr. Waynefred H. Villarba, Depth of Field PhD.Crim, printed by Wiseman’s Books Trading, https://www.youtube.com/watch?v=qfkvw-Lrn7Q Quezon City, 2000 5|Page