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Objectives

By the end of this lesson participants will:

  • Identify the major camera functions
  • Make news still photographs
  • Shoot video

There are obvious differences between still and video shooting. There also are differences in the location of the switches and operation of various cameras by brand and capability. However, many of the essential camera functions are similar across camera types, brands and capabilities. The purpose of this lesson is to help the user identify those major camera functions and locate and operate them on a variety of cameras.

The online journalist may be expected to produce both sill photographs and video content. The video shows action. Its story-telling capabilities work across time. For breaking news events it creates the feeling the viewer is there. For sill photographs the major advantage is to freeze time -- capture a moment -- deliver powerful emotional or dramatic content.

Video is rapidly growing Web resource as more users get access ot high speed Internet connections; however the sill picture remains an important resource in online news -- as a single image or as a part of a slide show or animation.

Camera Basics

The three primary features of all cameras are lens, shutter and image storage device (film, tape, computer chip, etc.).

Lens. The job of the lens is to focus the light entering it so that a clear image of what the photographer intended is sent to the camera's recording mechanism. There are two variables in that process that are important to the news photographer -- focal length and aperture. The glass in the lens will be curved. Lenses that bulge out (like human eye glasses) are convex. Lens that curve in (like a shallow bowl) are concave.

Focal length. In a convex lens, the light enters the top part of a lens, the optics of the lens bend the light and sends it to the bottom of the recording mechanism at the rear of the camera. the reverse is true for light entering the bottom of the lens. At some point behind the lens those light paths cross. This is called the focal point of the lens. The distance between the focal point and the lens is its focal length. In a concave lens the focus point is in front of the lens.

In practical terms, a lens with a smaller focal length will produce a wider angle picture than a lens with a greater focal length. Thus a 20mm lens is a wide angle lens that would be used to show a landscape scene, larger gathering of people, large building, etc. A 300mm lens is a long lens that will show a smaller part of the same scene. The long lens is used to get "close up" to objects far from the camera as in sports photography.

A telephoto or zoom lens with have a range of focal lengths that the photographer selects by twisting a ring on the lens or, in the case of an automatic control on the camera, by pushing a level to move the lens to a different focal length. Some cameras will have both optical and digital zoom capabilities. Avoid the latter. Digital zooms sample part of the picture already taken and enlarge that sample. This seldom produces sharply focused, quality pictures -- never when hand-held. Optical zooms use the properties of the camera lens to make the close-up picture; therefore, producing a much sharper, useful picture.

Shutter. The camera's shutter or iris is the mechanism at the back of the lens that lets light pass from the lens to the camera's image storage device (film, tape, computer chip, etc.). On most cameras the shutter or iris can be made larger or smaller -- allowing more or less light to pass. The size of the hole is called the aperture. It is usually described in f-stops. The smaller the f-stop number the larger the hole and the more light that can pass. An f-stop of f/1.8 lets substantially more light pass than a setting of f/11. A second function of the aperture is to aid in setting the camera's depth of field. More about that below.

A second concept related to the camera's shutter is shutter speed. In film camera's photographers could adjust the time the iris was open allowing light to pass to the film -- the shutter speed. The shutter speed was measured in parts of a second -- 1/60th was an average opening time -- one sixtieth of a second. To photograph fast moving objects like races or other sporting events, the photographer needed a higher shutter speed -- 1/250th or even much higher otherwise the iris let in light over too long a time and the subject appeared blurred because the athlete had moved during the time the iris was open. In digital photography there is no actual opening/closing mechanism on the camera, but the concept of shutter speed to so well known that it is still in use. In digital photography the shutter speed describes how long the camera's computer chip is allowed to take in light from the lens.

Automatic vs. Manual Functions

Most consumer cameras have a host of automatic features. Manufacturers realize that for broad acceptance of their products photography must be as simple as possible. Few ordinary citizens will take the time to learn or apply the detailed steps of setting exposures, focus and the like. Some professional cameras also have selected automatic settings. Many of these cameras also have systems that allow the photographer to turn off the automatic features and make focus, exposure, speed and other settings themselves.

It is essential for professionals to know what these key functions are intended to produce and how to make manual settings. This knowledge will enable the photographer to know when it may be satisfactory to use an automatic setting and when it would be advisable to set a particular feature manually.

Primary Camera Functions

Below are major common camera functions. Most apply to both still and video cameras.

Focus. Consumer cameras will have an automatic focus feature. It will be set based on what appears in the center of the scene. A problem arises with the primary subject is not in the center of the shot -- as in the case frequently when the rule of thirds is being used. In addition, sometimes a camera will have difficulty setting the autofocus in low light situations, scenes with low contrast and the absence of vertical lines in the primary field. In some still cameras, the photographer must depress the "take photo" button halfway to permit the camera to focus and perhaps set other automatic features. In most video cameras the autofocus is done quickly so as not to slow the photographer.

When the photographer wants to turn off the autofocus feature or there is not autofocus feature as on most professional cameras, the focus must be set manually. The process varies. On some cameras there is a focus ring on the camera that can be twisted to select the focus. Others will have focus dials or joysticks to adjust the focus.

The autofocus should be turned off when shooting sequences. As the camera is moved from one location to another for the shots, the camera may refocus during shots thus ruining their usefulness in editing.

Depth of field. This is the amount of the scene the camera sees that is in sharp focus. Obviously, the photographer wants to primary subject of the shot to be in sharp focus; however, it may be desirable to have other parts of the scene blurred so that attention is focus in the primary subject.

A camera will have greater depth of field -- that is greater distance in the scene that is in acceptable focus -- with a smaller aperture (higher f-stop). to be able to use a smaller aperture the photographer may have to add more light, remove any neutral density filters and/or slow the shutter speed. The photographer can reverse these steps to reduce the depth of field.

White balance. As we noted in the lesson on light and lighting (See Use Light and Lighting), the color of the light varies across a wide spectrum from the reddish glow of a match or candle to the bright blue of a cloudless sky. To record pictures that the human eye will recognize as "normal", it is necessary to set the white balance of the camera for each shooting situation. In setting the white balance, the photographer is telling the camera what is actual white in this particular light. Many cameras will ahve an automatic white balance. They may also have some additional categories of light that the photographer can select as a part of the automatic white balance routine. Here is the list from a middle-grade consumer video camera: Automatic, Daylight, Shade, Cloudy, Tungsten, Fluorescent, Fluorescent with daylight bulbs, and Custom.

If the dominate light source is any of those, the photographer may get satisfactory results by selecting one from the list; however, when there are multiple light sources or the photographer is uncertain of the impact of the automatic settings, the photographer can use the custom setting to by-pass the automatic selection. The steps in the custom process are these: Set up the lights as one intends to shoot, display a white card at the center of the scene with the light showing on that card; zooming on the card to fill the viewfinder; and set the white balance button on the camera. The photographer must repeat this process for each new lighting set-up or return the camera to the automatic function.

Aperture and Shutter Speed. Beyond getting the scene in focus, these functions have the most to do with producing quality photographs and video. Consumer cameras will offer automatic settings for each function. The automatic setting is based on a calculation of the average of what the camera sees in the scene. Sometimes automatic is not satisfactory.

Middle-grade or higher consumer cameras will have some additional aperture/shutter speed settings the photographer may select for given situations. Here is the list from a mid-grade video camera: Portrait (large aperture to blur the background), Night, Beach, Spotlight, Sports, Snow, Sunset, Fireworks. These settings will come from the averages of those situations. Of course, those averages may not work in specific situations. In those cases the photographer will want to use manual settings.

A primary example of the problems automatic settings produce is when shooting a subject in shade with a bright background. The automatic setting is likely to produce a picture in which the subject is too dark. In that case, the photographer should turn off the automatic settings; zoom in on the subject; set the aperture to produce the desired exposure for the subject. In this situation the bright background will like be over exposed and show little or no detail. An alternative would add light from additional light on a reflector to the subject in the shade in order to reduce the contrast the camera was attempting to deal with. Even with the addition of light, the photographer should set the aperture manually. Having set the aperture manually, the camera may select a shutter speed automatically. With professional cameras the photographer can set both the aperture and shutter speed manually.

In another situation the photographer may recognize the need to capture fast action. The photographer may want to select a faster shutter speed than the camera might select in a given light situation. The photographer can select the shutter speed and allow the camera to set the aperture, unless the camera enables the photographer to set both.

Filters. Glass filters may be screwed on that front of the lens of many cameras. On professional camera, particularly, the square frame (matte box) can be fitted in front of the lens and filter inserted in that frame. Both types of filters change the characteristics of the light reaching the lens. The three most common filters are the neutral density, polarizing, and UV filters.

The neutral density filter reduces the amount of light reaching the lens without changing any of the other characteristics of the light -- its color temperature, etc. These filters come in various shade of darkness. They permit the photographer to use a wider aperture (lower f-stop) and gain the advantages of reduced depth of field.

The polarizing filter reduces the amount of light slightly. It removes glare that may come from reflections off windows, snow and water. The process increases the vividness of the colors in a scene.

The UV filter is also known as a clear filter. It restricts Ultra Violet rays from reaching the lens. These rays are invisible to the human eye; however, they can add haze to photos. The UV filter also serves as protection of the camera lens from dust, dirt, finger prints, etc.

Tripod. The photographer's most important tool besides the camera is the sturdy tripod to steady the shots. Holding the camera -- still or video on one's hands or supporting a large video camera on one's shoulder may be a necessity in some breaking news situations; however, it should not be standard practice. Surprising as it may seem, it is hard for most people to hold a camera steady for the time it takes to make the photograph at 1/60th of a second. It is even more difficult at slower shutter speeds. The consequence of camera movement are blurred still photos and shaky video in which the entire scene bobs as if it were on a boat riding on waves of water. Even the act of pressing the "take photo" button can produce a blurred shot. Mount the camera on a tripod whenever possible or place it on some other steady firm support.

Picture Resolution and Quality

Pixels. Pixels (a condensed word from picture and element) are the units of measure of the size of a digital picture. They are the equivalent of the dots that make up an ink-on-paper picture, often expressed as dots-per-inch. Each pixel contains a sample of the original image expressed in some combination of red, green, and blue color. Colors on the Internet are rendered as some combination of these three colors expressed in numbers for each color between zero and 255. A value expressed as three zeros will produce black. A value expressed as three 255s will produce white.

The quality or detail of a digital picture is often displayed as the number of pixels. A 800 x 600 rectangle picture would contain 480,000 pixels. By contrast a 1920 x 1080 (HDTV quality) rectangle would contain more than 2 million pixels. Obviously, the greater the number of pixels the closer the picture will be to the original scene. In digital video shot at 24 frames per second, the number of pixels and thus the size of the file is substantial. Picture quality can also be represented by pixels-per-inch (ppi). A larger ppi is useful in printing digital pictures. It is not relevant to computer displays since the important figure is the total number of pixels in width and height.

Acquisition Formats. As a general rule, the photographer should acquire photographs and video at a quality at least as high or higher than their intended use. Photographs and video are stored in the image storage devices of the cameras in various formats and sizes.

Most still pictures are stored as JPEG files, which has become the standard for still image compression for presentation on the Internet. It is named for the Joint Photographic Experts Group. JPEG files can be exported from the camera and edited/processed by wide variety of software programs. The JPEG format renders pictures with a combination of three colors -- red, green and blue. The values of each of those colors in combination produce colors from white to black across the color spectrum. Many cameras permit the photographer to select the size (number of pixels) of the JPEG file ranging from large to small. Most cameras will have a default file size that tends to maximize the number of photographs that can be stored. That size may not be size the photographer would prefer. Some cameras also permit photographs to be stored in RAW format. This is and uncompressed file that enables the photographer to make editing decisions about the photo in the post-shoot production. However, there is no standard for the RAW formats. The cameras and the software that comes with them must be used to transpose the photograph into a usable format for editing and distribution.

An alternative to the RGB format is CMYK -- cyan, magenta, yellow and a key color, usually black. This color format is used in printing (ink on paper) because it produces higher quality reproduction than the RGB format.

In video, unfortunately, there is much greater variation in the acquisition formats than for still pictures. The process is evolving so rapidly that the industry has not developed a primary standard. The original video signal has so many elements that storing it in that form is not practical. All of the systems employ some codec (software that can convert a raw stream of video into a compressed form). Compression involves taking sample of the original stream and storing the results of the sampling step. This compressed video is exported from the camera's storage device, often with proprietary software specific to that camera or company, to an editing system for post-shooting production and subsequent export to the Internet or other display service. Many cameras permit the photographer to select the quality level for acquiring the video. Higher quality video formats require much more space, but provide the editor greater options in the editing process. The higher quality formats record at resolutions as high as 1920 by 1080 -- top of the HDTV range.

Display. The equipment that displays digital photographs or video -- TV screens, LCD projectors, computer screens, etc. -- also use the pixel terminology to describe their capabilities. The initial display format for the Internet was 640 x 480. It increased to 800 x 600. It is now becoming 1024 x 768. Before high definition television, the television screen format was a 4:3 ratio of width to height -- 720x480 NTSC and 720x576 PAL. (NTSC and PAL are television display formats. The former is used in the United States and the latter in most other parts of the world.) The high definition format is 16:9 with pixel capacities ranging from 1024x768 to 1920x1080.

The editing process for the photographs and video transforms the original images into the appropriate size formats for display by resizing or re-sampling the pictures.


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