There are numerous detection devices available and choosing the right one to protect a particular area isn’t always easy. There is a whole range of circumstances to take into account — the size of the room, what’s in it, even how it is constructed, as well as what’s outside or even across the road.
You may need one or more types of detectors in any one area — for example, there are bound to be doors and windows to protect as well as the room itself. There may also be very large areas of glass, such as a patio door, draughts or heating, which may make it difficult to site certain types of detectors, and you may have pets in the house which will mean careful positioning and directing of the detection pattern. Read the rest of this entry »
There are no specific British Standards for control panels (or alarm devices themselves), although elements of BS 4737 relate to features found in alarm equipment. This is likely to change with the introduction of European Standards which will, for the first time, require individual components to meet levels of performance and construction.
It is very important to understand how an alarm system is operated if false alarms are to be avoided. To reduce this risk, manufacturers have been making instructions easier to follow and many panels now incorporate a Liquid Crystal Display (LCD) giving plain English step- by-step instructions to guide users through the arming, resetting and disarming procedures. Read the rest of this entry »
The extensive range of equipment available can prove very confusing. Your main aim is to find a system which is easy to understand, uses proven technology and can be extended, if necessary, at a later date.
Personal recommendation is probably the best way to choose a company to install your alarm system.
Then, if the installation or system should prove unsatisfactory, you do at least have an official organisation to approach to take up your complaint and investigate the situation.
You should obtain at least three quotes from reputable installers and remember — the cheapest may not necessarily be the best value. Read the rest of this entry »
The most important additions to the camera outfit are the extra lenses. If you have always used a standard lens on your camera, you may not find it easy to decide which would be the best lens to buy next. Obviously, you want to start with the one that will be the most versatile for your type of photography. As a first buy, most photographers choose a wide angle lens (28mm) or a telephoto lens (135mm). If you like taking scenic landscape pictures or you want to include a wide area without having to step back with the camera too much, then a wide- angle lens is a good choice. Read the rest of this entry »
The biggest attraction of a 35mm single lens reflex camera is its versatility. Not only is it a useful piece of equipment in its own right, but it can be the ‘heart’ of a complete camera outfit. You can add things like extra lenses, filters, a flashgun, a tripod, as and when you feel you need them, to help you get the results you want.
Smaller items—a blower brush for cleaning lenses, or a cable release, for example—also form part of the serious photographer’s equipment as the collection builds up. And, of course, you will need a gadget bag, or a carrying case to keep everything in. Read the rest of this entry »
The lens-to-camera attachment is very important on SLR cameras. It must be easy to fit, light-tight, and link up smoothly with the camera’s controls. There are two basic types of lens mount—screw thread and bayonet. Screw thread mounts: found on the older or less expensive SLR models. Their great advantage is standardization. All screw thread lenses fit any make of 35mm camera body made for this type of lens mount. Read the rest of this entry »
A camera which is reasonably compact, easy to operate, and can take a whole range of lenses opens up dozens of new possibilities for any photographer. Telephoto lenses for sports action pictures and better portraits, wide- angle lenses for depth in sweeping landscapes and pictures in cramped spaces, or close-ups of insects using a macro (close-focusing) lens. The pentaprism SLR camera can provide all these things. It is the most popular interchangeable lens camera, widely used by amateurs and professionals alike. There are others with interchangeable lenses—for example medium format SLR cameras and some viewfinder cameras—and these are discussed in detail later on. Read the rest of this entry »
Most modern cameras make it impossible to make a double exposure unintentionally. But sometimes double or multiple exposures provide unusual and interesting results.
A few cameras have a switch or lever to allow the shutter to be retensioned without advancing the film to the next frame. This makes accurate register of the subject components possible and gives the most successful multiple exposures. Read the rest of this entry »
Even the most accurate through the lens exposure meter can be fooled by a subject surrounded by large dark or light areas, subjects which are predominantly back lit, or those against unusual backgrounds. These can influence the meter, providing false information about the light level. Thus the main subject is over-exposed if the meter reacts to a large expanse of black background and, conversely, underexposure of the subject results if it is back lit or surrounded by a large bright area. Read the rest of this entry »
This is usually found on a camera top plate. The index shows the exact location of the film within the camera and thus enables accurate measurements and calculations to be made. It is most useful for close-up work when you may want to measure bellows extension or extension tubes to help you work out magnification and exposure. Close-ups are difficult to focus with a non-reflex camera because the focus cannot be checked through the viewfinder. Instead the distance from the subject to the film must be measured accurately. Some cameras which do not have a film plane index have a serial number engraved on the top plate. The top of the figures often corresponds to the location of the film plane inside the camera. Read the rest of this entry »
