Apart from the shutter release, film winder, focusing and exposure controls, even the simplest cameras have a few additional knobs and switches that are either safety devices or provide an extra degree of control. Used correctly they may not only make picture taking more reliable but can also increase the versatility of the camera.
Here’s how to use the extras most commonly found on modern cameras, and in some cases what you can do if your own camera lacks them. Read the rest of this entry »
When you open the back of a camera to change the film, look inside and then press the shutter release. As the shutter opens the aperture can be seen beyond it. This shows more clearly if you look through the front of the lens or, on a camera with interchangeable lenses, take the lens off and look through that. Turn the aperture control and the size of the aperture will alter within the lens as you change the settings.
As the size of the aperture changes, so does the brightness of the light allowed through the lens. Aperture size, and therefore brightness, is controlled by the iris diaphragm, made up of a number of thin, interleaving blades which rotate to make the aperture larger or smaller. Making it smaller (stopping down the lens) reduces the amount of light reaching the film; increasing the size allows more light through. Read the rest of this entry »
The lens illustrated is the type usually fitted to an SLR camera. It encompasses more or less the same view you see with one eye closed. The information on the front of the lens gives its focal length (50mm), maximum aperture (f2), maker’s name, brand name, and serial number. The side view shows scales for focusing, aperture setting and depth of field.
Modern lenses are made up from several glass elements ground to a precise shape and mounted inside a tube. Read the rest of this entry »
An obvious failure symptom is when you select a drying cycle and attempt to start the dryer, but it does not run. To find the cause of the problem, move the dryer out from its position and unplug the power cord.
If line voltage is indicated on the volt/- ohmmeter, check the dryer power cord as possible cause of the problem.
To avoid any incorrect readings when using the volt/ohmmeter, always “zero” the ohmmeter before making continuity checks on components. Read the rest of this entry »
The brush roll is supported on bearings at each end so the barrel rotates freely. Types of bearings, barrels and brushes differ from model to model as well as between manufacturers. Some manufacturers supply individual parts for the brush roll, such as brush strips, bearings and barrel; others supply only complete assemblies. The brush roll on some models may have removable brush strips, whereas others may be a solid brush roll of wood or plastic with fixed brushes. A small selection is shown here to highlight the differences. Read the rest of this entry »
The upright style of vacuum cleaner is perhaps the best for large areas of carpet. It is especially good at removing dirt embedded within the pile and pet hairs from the surface, even on sculptured carpets. A drawback with the basic upright cleaner is its difficulty with cleaning stairs. The problem has been overcome with the modern combination of upright and cylinder cleaner. This type may be the best option if you have large areas of fitted carpet and staircases. The motor within the upright cleaner creates the airflow (suction) and drives a rotating brush roll, often called an agitator barrel. Read the rest of this entry »
The domestic vacuum cleaner has been with us now for some 90 years, during which time it has become the most popular labour-saving appliance in the home. The basic principle of operation is quite simple. An electric motor drives fans to create a fast-moving air flow. At one end, a vacuum (suction) of air is created, while at the opposite end the air is exhausted. If the air is moved quickly enough at the inlet end, it will carry with it any debris that enters the airflow. A means of removing the debris from the airflow is required to prevent its redistribution as the air is expelled. Read the rest of this entry »
Cord rewinds are now found on all types of cleaners, from simple hand-operated versions to the fully automatic rewind at the touch of a button. Many auto cord rewind systems use open coil springs and great care should be exercised if a stripdown of these systems is called for. Protection for the eyes is recommended. Goggles afford adequate protection from the spring itself or any item that it may throw out in the event of its slipping from position.
Operation of the cord rewind relies on tensioning of the rewind spring as the cord is pulled out for use. A small brake pad prevents the immediate return of the spring and cord drum to its original position. Read the rest of this entry »
