Lens/shutter cameras have lenses affixed to the camera body and incorporate the shutter in the lens. Cameras of this type separate the viewfinder from the lens; that is, the scene is observed with the light coming through the finder, not the light coming through the lens. This may cause some shift in what is seen and what is taken, especially with close-ups; this is known as the "parallax effect".
Focusing systems may be automatic (via an "active infrared" system that sends out a beam of infrared light and ranges distance based upon reflection) or fixed, which means the lens is set at one focusing distance.
Autofocus lens/shutter cameras set focusing "zones" rather than focusing upon a discrete distance; generally, the more the zones the more precise the focus. Less expensive cameras have what's called a "focus free" system, an odd term that means that the camera is set at one focusing distance. Focus with these cameras is less precise.
Lens/shutter cameras may have an integral single focal length or a zoom lens; the latter allows for a variety of angles of view. In most, exposure and film handling is automatic, with a built-in flash that fires when the light sensor detects a need. Because the flash is mounted in the body close to the lens, pictures of people and pets in darkened rooms can yield an effect called "red eye", a demonic look that is particularly disturbing in small children. An attempt is made to reduce this problem with a "red-eye reduction" flash setting, which sends out a burst of pre-flash light to, theoretically, cause the subject's pupils to constrict, thus to reduce "red-eye" in the picture.
More expensive lens/shutter cameras have a variety of exposure modes (shooting "scripts" that set the camera up for various lighting and subject conditions), and even allow for some focus and exposure control. Point-and-shoot cameras are perfect for candid pictures of the family, vacation snapshots and casual photography that requires little user input or effort. While lens/shutter cameras with more advanced features are available, the simplicity of use is their main appeal.
Point and shoot 35mm cameras offer a larger film size than 24mm Advanced Photo System cameras. All other things being equal (quality lens, good exposure) the 35mm film offers a slight advantage when big enlargements are made. The three picture format options and compact size of the 24mm cameras may also appeal, thus the choice between the two may come down to personal taste and the appeal of the camera's design and handling.
Here are some differentiating points among 35mm point and shoot cameras:
Lens - Zoom or Fixed Focal Length:
A zoom lens offers a number of angles of view in one lens. This is the most versatile choice. Fixed focal length lenses, however, may allow for shooting without flash in dimmer light and may have a slight edge in sharpness. The ratio, or range of the zoom should also be considered. Some point and shoot cameras offer a fairly limited zoom range, for example, from 38 to 55mm. This is a slightly wide to normal angle of view. Others offer wide range from wide to telephoto, such as 38 to 105mm. This offers greater shooting flexibility.
Autofocus or Focus Free:
An autofocus point and shoot camera automatically focuses on the subject in the center of the viewfinder. Some models may offer focus lock, which means that you can place a subject at the center of the finder, lock focus and then recompose so that the subject can be placed at the side of the frame without fear of losing focus on it. Focus free means that the lens is set at a fixed focusing distance. Autofocus in point and shoot cameras works in zones. The greater the number of zones the more precise the focusing.
One of the ways that lens shutter cameras offer exposure control is through flash modes. This allows you to choose how a scene will be rendered in both daylight and dim light. The more the flash mode options the more creative you can become. Be sure to get a camera with red-eye reduction mode. This works with a pre-flash prior to the flash used for exposure and does reduce the red-eye effect often seen when photographing people indoors. Flash off, or flash defeat turns the flash off even if the light is low. This comes in handy when photographing in situations when flash is prohibited or would be indiscreet. Daylight fill flash is used when the subject is in shadow or when the sun is behind the subject outdoors. It yields better picture quality in many instances. Slow sync or night flash mode uses both the ambient (prevailing) and flash light for exposure. It gives a more natural look to flash scenes made in low light, as it extends exposure to bring in more of the background light quality in a scene.
This is available in QD models and it allows you to have the date, time and sometimes custom captions imprinted on the back or the face of the print.
Because most lens shutter cameras allow for no user input on actual aperture and shutter speed settings, some cameras offer picture modes that can enhance the type of picture you want to make. When set, these modes program the exposure and focusing system to perform in various ways. Portrait mode, for example, makes the background less sharp than the subject and adds a sense of dimension to portrait subjects. Infinity mode sets the lens to focus at infinity. Because these cameras work with an infrared beam to set focus, any interference in the beam reflectance will cause focusing on that particular spot. If you're photographing through a window, for example, the beam will stop at the window pane and cause the background to go unsharp. Setting the camera on infinity mode will bypass the focusing system and cause the lens to focus beyond the obstruction. Close-up mode can be used for pictures of flowers and other close-up subjects. This sets the lens focus accordingly. Many cameras will have a focus confirmation signal that will inform you when you are focusing too close. Setting close-up mode ensures that you'll be able to focus closer than normal. Action mode programs the camera to set as fast a shutter speed as possible and is great for sports or subjects in motion. In short, picture modes allow you to customize the camera for particular shooting scenarios. They may be a bit confusing at first, but they can be a great help in getting better pictures.