Camera terms explained: What means what and things to look out for

Megapixels/Sensor Size

Although many thought the 'megapixel race' was over, manufacturers continue to push resolution higher. As a rule, don't worry too much having a high megapixel count, especially where compacts are concerned as their sensors are smaller, so cramming too many pixels onto such a small area can actually limit the amount of light per pixel, thus limiting the resulting image quality. Consider that a single 1080p HD TV screen's native pixel count only equates to 2.2MP - so a 14MP still image may just end up costing you more hard disk space.

Lenses

Most cameras come with zooms, such as 35-105mm. The lower the first number the more wideangle the lens can go (great for big groups and wide views) while the higher the second number the more it can zoom in (perfect for distant subjects). But if that superzoom says 24-480mm don't necessarily expect premium quality throughout the range - so much needs to move within the lens to achieve this that some sacrifices must be made. Wide apertures are also becoming more common on compacts - the lower the aperture number the 'better', as more light can be captured in lower-light scenarios. However, f/1.8 on a compact won't give you the same shallow zone of focus (depth of field) as f/1.8 lens on a DSLR camera, due to the much smaller size of a compact camera sensor.

Rear Screen

This is one of the technologies that's come along speedily in the past 12 months - due, in part, to the introduction of AMOLED (or OLED) technology. OLED (Organic Light Emitting Diode) is more fluid for motion playback, and not only has a higher contrast ratio for better dynamic range, but it also consumes less power too.

Then there's the screen's ratio. More widescreen (16:9 ratio) displays are being used - great for shooting movies, but not so great for 3:2 or 4:3 stills which will appear smaller within the screen's real estate.

Lastly there are now a lot of vari-angle offerings coming to market. This is where the screen is 'hinged' onto the camera and can be pulled out and rotated around through vertical and horizontal angles for more creative positioning.

Viewfinder

Many compact cameras lack viewfinders entirely, as 'Live View' - a constant live preview to the camera's rear screen - has become dominant in this end of the market.

Traditionally optical viewfinders have been used in SLR cameras for many years. More recently, however, the rise of new technology and demand for smaller, more handheld product has led to Electronic Viewfinders (EVFs) taking pride of place in many cameras. Electronic versions may not be as kind to the eye, but are still a great option to have - viewfinders of any sort are ideal when shooting in bright sunlight, or to take a more traditional approach to framing. 'Field of view' is also a clincher for many - this is the percentage of the final frame that's visible in the viewfinder.

Movie Modes

'Stills' cameras are very movie-capable these days. HD 720p (1280 x 720 pixels per frame) is less resolute than 1080p (1920 x 1080 p/f) but discerning this by eye is possibly less important than the difference between interlaced ('i') and progressive ('p'). Interlaced means half the lines display on one frame and the opposite set of lines on the following frame - it's so fast your eye won't notice, except when fast-moving motion or panning happens as this can cause 'tear' where objects appear to be lagging. Progressive means all lines are shown in every frame, and so is the smoother of the two.

Then there are frame rates: 24 or 25fps (or 50 fields) is much like the Hollywood studio cameras, so use this for a more cinematic feel. 30fps (or 60 fields) is a common standard but looks more like a 'home movie' despite its smoother playback.

Buying Guide Links

Compacts
Advanced Compacts
Bridge/Superzoom compacts
Compact System Cameras
Entry-level DSLRs
Mid-Price DSLRs (Under £1000)
Advanced DSLRs (Over £1000)