Firstly...what is a digital camera?

If you already know just skip this section and scroll down to the next one.

You do need to have a basic understanding of how a camera works or not only will it be easier to compare cameras, it will also be much easier to understand how to get the best results with them.

Quite simply a digital camera is one that takes a visual impression of what the user points the lens at and stores the picture as digital information, in other words as a series of 1s and 0s, instead of having a chemical process that reacts to light like a conventional camera.

The concept is much the same as in a conventional film camera. All light is formed of units of energy, different colours give off a different type of energy. In a traditional film camera the light is reacted with a chemical film which is exposed to a snapshot of the energies coming in through the lens from whatever you point your camera at, the chemicals react differently to different light energies and so produce and image that corresponds to whatever scene you took a picture of. The more you expose the film to the light energy the stronger the reaction, hence in dull or dark conditions a longer exposure will produce better results, too long of course will simply ruin the film.

In a digital camera, instead of a chemical film there are tiny and very sensitive electrical units which react to the light and produce a small current/charge which is measured electronically and stored as electronic code which can be interpretted by the camera and compatible photo software and displayed on your PC or printed on a printer.

Probably the most important aspect to understand when it comes to the working of a digital camera is what light is. The majority of people don't know, but it will affect your picture taking dramatically if you understand a little more. Light is made of energy particles called photons, these are physically real parcels of energy which are fired out from the object you are looking at. When the camera shutter opens these parcels of energy enter into the camera via the lens and hit the sensors. So if you move your camera around very fast while taking the picture you get a range of photons from various objects, maybe a couple from a chair, a couple from the wall, a few from the tree outside, all entering and hitting the same sensors, hence what you capture will look blurred. Think of it like several balls being bowled at a batsman at the same time - it's just not cricket! It works much better if only one ball is bowled at a batsmen at one time.

So what is the best digital camera in the world?

The best digital camera, or digital video camera for that matter is...
...no of course its not that simple, one persons idea of the best is different from the next persons and it depends entirely on what you need and what you can afford. If you really want the best digital camera in the world it takes a little effort and some research, lucky for you we have prepared a summary of all the important points of what you should look out for to help you decide.

What to look for in a digital camera.

1.Resolution.

One of the first things you will see in a camera's description is the resolution which is measured in megapixels, or MP for short. Oddly most people dont bother to understand what this is and still feel that is some measure of quality or value of the images a digital camera will present. Quite simply it is a measure of size. A PC screen may have for example a resolution of 1600x1200 which would be 1.92 MP, so if you have a camera with a bigger resolution than 1.92 you will never see any difference on your PC. Of course it also makes a difference to the size of the print you can have, but the resolution of your printer will also make a big difference here. Generally a standard photo quality resolution would be considered 300 dpi (dots per inch), which (if you take 1 inch=2.54cm) is equal to 118.11 dots per CM, so if you want a top quality photo that is around A4 (21cmx29.7cm) in size you would need (21x118.11) x (29.7x118.11) = 8700597.598, or an 8.7 megapixel camera, but you will still get very good quality prints at this size with a 4MP camera.

In reality few people will ever print off photos of this magnitude, and even if you do it is likely to be a rare occasion and a camera with a much lower resolution will still produce very desireable results. You may wonder how many megapixels are used on bollboard posters and if such a camera exists, but the fact is that large images are often viewed at a greater distance by the human observer and the resolution needed to create the image is much lower. If you get close up to a billboard you will see lots of coloured dots and the picture will only make sense from a distance. This is to illustrate the fact that the resolution required for a decent visual experience really isn't that great. For very good quality photos you will really only need between 2.1 and 6 MP, you should only consider higher than that if you are a very keen enthusiast or professional photographer, although if a suitable camera is within your budget there is no reason not to have the extra possibility just in case.

An important thing to note about resolution is that it is not a measure of the quality of image that the camera will take, only the size, and as we all know, size isn't the most important thing, its what you can do with it that counts! A very good 3MP camera will take a better photo than an average 10MP camera, so don't be fooled by the MP count.

2.Quality.

So if MP doesn't tell you how good a quality the images will be what does? Well one of the key things is the photosite, this is the area beyond the lens inside the camera where the light falls and is converted to a digital signal. These can vary greatly in size and often a larger area will allow a much more detailed signal for each pixel to be recorded giving a truer picture of the light and detail of the original scene you are trying to capture, the problem is most camera descriptions will not include the size of the photosite. As a rule cheaper digital cameras will have a small photosite of around the size of the nail on your little finger, the next range up will have photosites comparable to ASR cameras, very approximately the size of your thumb.

Other factors that will affect the quality of the image taken are the lens, this part collects the light and sends it onto the photosite, if it doesn't perform well the image captured will be poor no matter how good the rest of the camera is. The internal software and electronics of the camera will also affect how well and accurately the images is stored. There is a lot to consider but the main point is not to rely on MP as a measure of quality, of you can read a review by someone who has used the camera, their opinion is often a good guide as to how well the camera performs.

3.Storage Capacity.

Similar to other digital device such as mp3 players, computer hard disks etc. digital images are stored in bits - a series of 1s and 0s and they take up space. So the more photographs you want to take before transferring them to the computer or docking station, the more storage capacity you will require. This need is increased still further if you also want a camera capable of taking video/movie clips, for carrying files, and for playing mp3 etc.

How much space is taken up will depend on what megapixel definition the camera has and also on what you have it set to. Very good quality photographs can be taken with a resolution of 2.1MP and depending on what you are taking a picture of, the image size can vary dramatically but as a guide is likely to be between 1 and 1.5 megabytes (MB). You may have a camera that is capable of 10 megapixel resolution or more, but you do not need to take pictures at this resolution all of the time.

A memory of 32 megabytes will hold around 24 images at a 2.1 MP resolution. So if you want to take a three week trip around Australia and you are keen photographer, and want to take a few movie clips too, you will need a lot more than this. Often storage is by a removeable card such as compact flash, secure digital, xD-Picture Card, MultiMediaCard, or similar and this is useful as you can take a few cards with you and vastly extend your storage capacity, but remember that you will have to pay extra for these cards to extend your memory, so a few pounds more for a camera with a larger supplied memory may be worthwhile if you can afford it, especially if you intend to take movie clips. Some cameras will be compatible with more than one type of card which increases your options.

Generally speaking a camera that has no ability to increase storage is to be avoided unless the built-in capacity is more than large enough for your requirements.

4.Portability.

Some cameras are tiny and can fit on a keyring or inside a pen, others will weigh heavily on your neck and take up a good deal of boot space. Really you need to decide what you want to use your camera for, you can get decent cameras that are barely larger than a credit card capable of a good image quality and enough capacity for 25 or so pictures. Very portable and convenient but often with no flash or movie clip functionality. Generally anything smaller than a cigarette box is going to be more of a novelty unless you spend alot of money for miniturised technology, although no doubt this will become more available and prevalent as time goes on as we are seeing with the mobile phone industry which is beginning to release camera phones capable of taking quite decent photographs.

5.Docking devices.

Many cameras come with docking devices that allow you to simply place them in the dock and transfer files directly to the computer or even print directly. They can be very convenient but will add significant expense to your purchase. Often cameras may dock directly to a printer and while there is an increasing cross-brand compatability for this function it is also often the case that a specific brand of camera will need/operate better with the same brand of printer. Beware of older cameras that will essentially be useless without a docking device, really you want something that is capable of USB and/or firewire connection in addition to the docking station. You may also find that some cameras come with a card reader seperately or you may need a card reader to transfer photos from the camera to the computer, these can add extra expense and are also a little less convenient as you need to manually remove the card from the camera and place it into the reader.

6.Power Source.

Different digital cameras give very different battery life, some will be able to use rechargeable batteries of a standard size, some will have their own built in batteries. Are there batteries included? What happens if a built in battery begins to lose its sparkle like a mobile phone battery does - can it be replaced? How long will the power last and how long will it take to recharge. Often this may have a bearing on whether a camera has an LCD screen and how large, bright, and efficient the screen is.

The more you use the display the less time the batteries generally tend to last. Some units last quite a short time with constant use and standard AA batteries can last as little as a couple of minutes. Cameras and their screens are becoming increasingly efficient but battery life can be an important consideration as can any energy saving features such as auto-shutdown. Most cameras will now retain the memory even if the batteries are flat, often an advantage of storage cards, but beware of the few that may remain that will lose all of the photos if the batteries fall flat, even more important if you are considering a second hand purchase.

7.Zoom, optical and digital.

Digital zoom is effectively a pointless tool, it will enlarge the image but with a proportionate loss of quality and it is possible to enlarge digital images on your PC when you upload them. You will be unable to see this loss of quality properly on the comparatively small preview screens that most cameras are provided with and it can seem like there is a zoom effect when you are taking the picture but it is more or less a pointless feature.

Optical zoom by contrast is very useful, as this affects the focus of the lens on the area being photographed and there is no loss in quality of the digital images taken. Optical zoom is usually acheived by movement of the lens at the front of the camera, this may be manual or automatic, and may be progressive or by preset steps. More professional style camera will have the ability to add extra lens extensions and increase this function and you will need to decide according to your needs. A 2 x optical zoom will be entertaining and will acheive some impressive results, a 3 or 4 x optical zoom is usually more than sufficient for the average user and even for the keen hobbyist, above and over this may entertain the average user for a short time but is unlikely to be something you use with any regularity if at all.

8.Flash.

No, not all cameras come with a flash and those that do can have quite a variation in the strength of the flash. Higher spec. cameras may have the ability to focus and vary the flash intensity automatically or possibly manually. Most standard cameras will have a fairly standardised flash which allows pictures to be taken in the dark but is optimised for a distance of around 1.5-2 metres. This means that at the recommended distance colours etc. should appear as they would do in daylight, taking pictures closer to the subject means they will suffer from the whitening effect, and further away means they will appear duller or darker. If you are going to be taking a large number of photos in the dark then a variable or high quality flash is certainly something that you should consider.

9.Variable exposure/nightshot.

Following directly on from flash is variable exposure which also effects the appearance, brightness and colour of the pictures you take. Exposure is a measure of how long the shutter is opened to allow light in to hit the photosite. The longer it is exposed to the scene being photographed the stronger the image in terms of brightness and colour.

This is usually how the nightshot function works, when selected it will automatically increase the exposure and allow more light in, however the increased exposure time makes the camera much more susceptible to the effects of a wobbly hand or moving subject and often if people do not stay very still and your hand is a little shaky you will just get a very blurred photo. Better cameras with larger photosites or a wider lens/shutter will be able to let in the increased amount of light in a shorter time and so reduce the effect of and movement and subsequent blurring.

Some cameras will also incorporate clever electronics and/or software that will compensate for this movement and some nightshots can be quite stunning. In fact the effect of overexposure is often used by professionals to purposefully give the effect of movement. One such type you are bound to have come across is cars at night, the scene remains still and so looks as it should, although perhaps a little brighter but the cars will be a blur accented by the rear red lights forming a streak of red light across the image in line with the road.

Another use of variable exposure is to compensate for particularly bright/dull daytime conditions/photos taken indoors etc. Alot of cameras will have a light sensor which can automatically adjust the exposure although some sensors are more accurate than others. It is often worthwhile getting a camera that has both so that you can adjust the exposure manually if you wish to.

10.Auto focus, manual focus.

Focus sets what the camera is looking at to take the picture. Different objects at different distances will need to be focused on in different ways or they will look blurred. Most cameras now come with an autofocus facility which will automatically centre in on what you want to take a pciture of, but beware of this facility, sometimes it can prevent you from taking what you want. Say for example you want to take a picture of a friend who is standing in the middle of a field of tall grass, the camera may focus on the nearest blade of grass and your friend may be a blur in the background, whereas what you want is the other way around. Whether this is a problem or not will depend on how sophisticated the electronics of the camera are, but additionally if you feel you may want to take shots where something in the foreground is blurred and the focus is on something a little further away - particulalry the case when taking pics through windows, you should look for a camera that also has a manual focus facility.

11.Red eye reduction.

Red eye is the effect of the flash light entering the eye and being reflected off the retina back out and into the camera, it occurs predominantly in dark conditions when people have wide pupils to help more light enter the eye and aid their sight in darker conditions.

Red eye reduction (not elimination)is acheived when using the flash by having a quick flash before the picture is taken which will accustom peoples eyes to the bright light, followed by another flash as the picture is actually taken. This does usually work, but if the subjects of the photograph. Unless you warn everybody who is having their photo taken this invariably results in the picture being taken not turning out quite as intended as people often think the first flash means the picture has been taken and they will turn away of relax for when the picture is actually taken with the second flash. So it can help in conditions when everyone is warned but has rather more limited use than you may think. The second way of reducing red eye is via image processing software which can be very effective if done well.

12.Video and movie clip recording.

Increasingly popular and often included with a digitial camera is the ability to record movie clips or short videos. What a camera can offer in these terms can vary wildly from one camera to another, even within the same price range. Firstly there will a FPS rate which is how many frames per second are recorded. The standard movie FPS for the cinema etc. was always 24. So for every second of footage you shoot there are 24 still frame images. The measure of 24 means you can expect a movie clip that is fluent and without pause. At 15 fps you will still get an entertaining clip with a very slight notable delay between each frame, any less and while it is a moving picture it is clearly a notable difference from a good quality movie. Some cameras can take 30 fps which is notably clearer than 24 fps and a very good quality image.

It is very important to note that if you are shooting at 24 fps there are 24 still images which need to be stored in the memory of the camera or memory card you are using and this takes up a significant amount of space. How much space with depend also on the resolution of the movie clip. The majority of mid range or lower cameras will have a maximum resolution of 320x240 pixels for movie clips (a standard credit card is around 290x185 pixels). At this resolution 2 minutes of video is likely to fill a 32mb camera or memory card. A good resolution for movie clips is 640x480 but again this will take up much more memory, if you are keen on taking a large number of longer video clips at a high resolution you should really consider a digital video camera rather than a still camera that has a movie clip function, they can usually take still images too.

Again with movie clips time is often limited, if not by memory by the camera itself. Sometimes this can be as low as 10 seconds but if you stop now and count to ten you will realise this is not especially short and may be suitable for your needs. If you want to record your local band playing a full song or an airplane landing etc. you will need significantly longer. Fortunately many newer cameras are only limited by the memory as to how long the movie clip can be so your main concern may be the size/expandability of the cameras storage capacity.

Some cameras can film movie clips in night mode and some can not. Those that can may not be entirely effective given the blurring problems of increased exposure, but this may be feature you want to look for. You should also consider what format the movie is recorded in, MPEG, AVI etc. as this will effect which players you can play it on, although it is unlikely you will find a modern camera that records in a formate that cannot be read by all of the popular media players.

If you want sound with your movie clips your camera will need a microphone, either built in or one that can be plugged into it. Sound will take up additional memory to record too and this can vary in quality from very good to very metallic and tinny to completely useless. If you want your movies to have good audible sound, check out the mic. A built in mic often allows the camera to be used for dictation or for short audio notes on each photo you take which can be useful if you are likely to forget when and where you have taken pictures, or if you are photographing stock for an ebay sale for example.

13.Special effects.

It may be possible to use the camera to apply colour effects etc. This is really only useful if you intend to print directly from the camera instead of using photo editing software, and as you will be unable to preview the altered photo in its proper size without putting it on the computer screen this is less of an important feature.

14.Timer.

Most cameras will come with a timer so you can take pictures with yourself on, or so you can ensure the camera is stationary on a set object or tripod when the images is taken and so your hand pressing the button does not cause wobble. This can be a handy feature for ensuring that you do get in on some of your own pictures. The length of timer can be set or variable but around 10 seconds is usually enough to get from behind the camera and into the picture.

15.Interval shooting.

If you want to take pictures of a set scene at set intervals over a period of time look for this feature. You may want to take a picture of a flower blooming or clouds moving across the sky over a period of hours or even days. Most people will never make use of this facility so ask yourself if you need it. Additionally some cameras may be able to take a photo once an hour for days yet their battery will only last 1/2 a day, so if you want a camera that does this check the battery life and whether it also comes with a plug in adapter etc.

16.Continuous shooting.

Often associated with the papparazzi is that continuos clicking when they take a photo, what is happening is when the button is pressed the camera continues to take pictures at a set interval, possibly 3 or 4 images per second. This can be for a couple of reasons, it will give a set of pictures that put together can illustrate movement, but more often it is to capture a more natural looking photograph. How many pictures have you taken when someone blinks, or when they smile or laugh more naturally just after it has been taken, with continuous shooting you can capture more potentially useable pictures, but again remember that each picture will take up memory space.

17.Design.

The most likely thing to attract us to a camera is the picture, advert, or even the item in the shop window or under the counter. Shiny, expensive looking, classy, but wait...does it even take pictures or were you looking at a cigarette holder? Some feel style is more or less important than others but one thing to ensure is that the style does not inhibit the functionality.

A really slender, sexy unit may look stylish and minimalistic, but does it have the capacity you require, are the buttons as functional as they are good looking? It is often the case that a good exterior design will also enclose a great interior design, but not always. You can get a dated looking ugly unit that is the top of its class on the inside, and you can get something that looks a million dollars, and may cost it too but when you get under the hood will have you crying into your credit card statement for weeks. There is always a compromise on size, style, and functionality, you will need to assess the priority of your own values on what features and benefits carry the most importance for you.

18.Depreciation.

How much will you get for your camera in a year or two if you decide to upgrade will depend on the make, model and functionality, so keep this in mind too. You may buy a camera for £150 which will be worth £75 in a year, or you may buy one for £250 that is worth £210 in a year. Its obvious which one has really cost more.

19.Its your choice.

Sometimes the choice can seem overwhelming, but once you understand your requirements and also set your budget you will usually find that the camera will choose itself, and it will be the best camera in the world for you.