Lab

DIGITAL CAMCORDERS

After years of smiling grimly through endless, jerky home movies - help is finally at hand. With your PC you can turn the dullest piece of movie footage into a masterpiece. But how are you supposed to get your film from a camcorder onto your computer in the first place? With a MiniDV camera, that's how. These digital camcorders work just like a normal camcorder, except that you can plug them straight into your PC and download your footage directly onto your PC's hard disk. And the good news is that they've finally come down to an affordable price. We've tested five of the best budget models to see which ones are fit for a home movie mogul.

How DV cameras work

MiniDV cameras work in largely the same way as a digital stills camera. There's a lens that focuses light onto a sensor called a charge-coupled device or CCD. This turns the light into an electronic charge with a given value, or set of values. These values are then passed to an analogue-to-digital converter to be changed into binary data that a computer can recognise and work with. From there the footage is transferred to a tape where it's stored for later use.

However, this is where the analogy with digital cameras stops. Digital cameras take pictures that need about 1MB of storage space after they have been compressed to JPEG format. Digital video cameras need considerably more. Broadcast-quality video runs at 720x576 pixels at 25 frames per second - recording this as uncompressed data would require almost 30MB of storage per second of video. Data compression can reduce these requirements.

MiniDV cameras use their own file format, known as DV. This needs around 3MB per second of video. Only a tenth of the size of uncompressed video, DV footage retains extremely high video and audio quality. By comparison, a DVD video disc typically contains video compressed to about 1MB per second.

All this data still needs to be stored somewhere, and although optical discs such as DVD are getting bigger and cheaper, tape is still the most effective medium on which to record. MiniDV tapes can hold an hour of footage - that's 13GB of data - and cost around £5 each.

MiniDV cameras manage to fit so much information on to tapes half the size of an audio cassette by using a rotary head. The tape itself moves relatively slowly, but the magnetic head that writes to and reads from the tape is cylindrical and rotates at an angle to the tape, writing and reading data in diagonal strips. It's the same technique that's used in VHS video recorders. However, it does have one disadvantage - all those small moving parts need to be perfectly aligned to work properly, so MiniDV cameras are more likely to malfunction than a digital camera that stores its images on a memory chip.

With the data stored digitally, you don't have to worry about the tape degrading the video or audio quality - except if it comes to the point when your camcorder won't play your tape at all, or decides to chew it up! However, the real advantage of digital video cameras is that the video is already in a format your PC understands. When you capture video from a MiniDV camera to your PC's hard disk, you're making an exact duplicate of the data stored on tape. There are no headaches about video resolution and compression settings that come with capturing video from analogue camcorders.

Video capture is performed via a FireWire connection, sometimes known as i-Link or IEEE1394. All MiniDV cameras come with a four-pin FireWire port, and with the right cable you can connect this to a four-pin or six-pin FireWire port on your PC or notebook. Six-pin ports are a similar size to USB ports but are slightly chunkier and curved at one end. Four-pin ports are smaller and squarer and have a dimple along one edge. If your PC doesn't have FireWire, you can add it for around £15 in the form of a PCI card. Notebook users will need to spend around £60 on a PC Card adapter such as Adaptec's FireConnect for Notebooks.

MiniDV cameras are recognised by Windows without the need for any special drivers, and any video-editing software (including Windows Movie Maker that comes bundled with Windows XP) will let you transfer movie footage to your hard disk. You can see a video preview as you do it, and even control the camera's tape transport from the PC.

The best video-editing software will even let you plug your camera into your PC and TV at the same time. You can then edit your footage and preview the results on either the camera's own screen or, more usefully, on your television. This is a good way of finding out what your finished film will really look like when your granny plays it on her old TV. If you decide that your edit looks like it needs a little more work before you release it to your adoring public, simply discard your changes and start again.

What should I look for?

MiniDV cameras can be extremely compact, but the tape mechanism means they tend to be heavier than stills cameras. They're also designed to be held and operated with one hand, and this can make them slightly awkward to use. As you might be spending quite a long period filming an event, it's essential that your DV camera is comfortable to hold and use. It should fit snugly in the hand, while the controls should be easily accessible and sit just where you want them to. A comfortable viewfinder is also extremely important.

Eyepiece viewfinders are awkward as you need to squint with one eye to use them, so it's good to see that all the cameras on test come with a 2.5in LCD display that flips out of the side of the camera and can be angled in a variety of positions for comfortable viewing. Traditional viewfinders are also included too, but you'll be unlikely to use them unless strong sunlight makes the LCD screen illegible or you need to conserve batteries.

Camcorder designers have a strange passion for hiding sockets in the strangest of places, and although covering them up is a good idea to keep the grime out, each camera we tested left us scratching our heads for a minute or two trying to find the power, FireWire or S-Video sockets. Only the Canon MVX250i and JVC GR-D23 have room for a conventional S-Video output, with the others resorting to a smaller socket and a special breakout cable. On the subject of connections, the FireWire link between a DV camera and a PC works in both directions, carrying raw footage to your PC for editing and the edited video back to tape for archiving. However, not all MiniDV cameras support DV-in - neither the JVC GR-DX28 nor Sharp VL-Z100 do. In this case, you can always archive your footage onto DVD instead.

Some people will be happy to simply point and shoot, and the image quality of these cameras means that this will usually deliver great results. However, if you like to take a little more control over your video, you'll want some decent manual controls. All the cameras tested include a manual focus function - on some this is only a button push away, on others it involves considerable grappling with the on-screen menu. This may be enough to put you off ever using it. They also all come with some kind of exposure control, but this varies from the JVC cameras' simple exposure shift to the Sharp's full control over aperture size and shutter speed. It's only the two Canon cameras that place exposure control close to hand. None of the models on test have a lens ring for direct zoom adjustment, but they all have a variable zoom control that responds to gentler and harder pushes with slower and faster movement.

Still cameras use long shutter speeds to cope with dimly lit scenes, but because video is recorded at a set 25 frames per second, this isn't normally possible with video cameras. However, to help you film in extremely dim light, these cameras include a night mode, which effectively reduces the frame rate to allow more light into the lens for each frame. This is OK as a last resort, but the video becomes jerky and blurry as a result. Three of the models on test also have a lamp built into the front of the camera. These aren't as powerful as a conventional flash, but they're enough to film even in complete darkness.

Extra features are worth looking out for. A stills facility is welcome, but only if it's any good - one that just records a frozen image to tape won't compare well to the output of a proper digital camera. Canon's MVX250i is the only model here that rejects this technique in favour of a high-resolution sensor and an SD card slot for image storage. An accessory shoe (a clip on the camera to slot external devices into) can also be useful for upgrading the microphone or adding a flash or video lamp, but while so-called hotshoes provide power to connected accessories, others are nothing more than simple clips.

The most important thing to consider must be image quality. There's no point in the most comfortable design, the greatest controls and tons of extras if the quality of your videos isn't up to scratch. Most DV cameras work well in brightly lit conditions, but low and artificial light presents tougher challenges, and this is often where cameras fall short of expectations. A good zoom range can ultimately lead to better images too, but high magnification needs an effective image stabilisation system to avoid excessive camera shake. The cameras on test use digital processing to remove shake, but some systems work considerably better than others.

Finally, don't forget that audio is just as much a part of moviemaking as video, so microphone quality is important too. Some pick up lots of noise from the tape mechanism's motors, while others are warm, clear and noise-free.

buying decisions

It was hard to pick a winner from the five cameras on test, as even the worst performers were still capable of excellent results. However, we ruled out JVC's GR-DX28 and Sharp's VL-Z100 because the cheaper GR-D23 outshone them both. Of the remaining three, each one is a worthy candidate for your cash. If you see yourself as a budding amateur filmmaker and have the money to spend, Canon's MVX250i offers plenty of reasons to justify its relatively high price. Image quality is a clear step up from all the others, and the superior manual controls and stills function further add to its versatility.

So the final race for our Best Buy award was between Canon and JVC's entry-level camcorders. Both offer image quality that's far better than we expected at such low prices, but while the Canon MV700i performed better in well-lit environments, the JVC GR-D23 had the upper hand in dim lighting, and is also over £50 cheaper. Ultimately, though, it was the Canon's superior handling, controls and image stabilisation that clinched it, more than justifying its slightly higher price. We were also impressed by the excellent manual controls, the high-resolution CCD for stills photography and its useful USB port - ideal for transferring still images to PictBridge-compatible printers.