VIDEO CAMERA FUNCTIONS

Most domestic camcorders can do just about everything automatically. All you have to do is turn them on, point, and press record. In most situations this is fine, but automatic functions have some serious limitations. If you want to improve your camera work, you must learn to take control of your camera. This means using manual functions. In fact, professional cameras have very few automatic functions, and professional camera operators would never normally use auto-focus or auto-iris.

This is where most beginners ask "Why not? My auto- focus works fine, and my pictures seem to look okay." There are two answers: Although auto-functions usually perform well enough, there will be some situations they can't cope with (e.g. bad lighting conditions). In these circumstances you may be faced with unusable footage unless you can take manual control. More commonly, your shots will be useable but poor quality (e.g. going in and out of focus). Your camera can't know what you want. To get the best results or obtain a particular effect it is often necessary to over-ride auto-functions and go manual

ZOOM This is the function which moves your point of view closer to, or further away from, the subject. The effect is similar to moving the camera closer or further away. Note that the further you zoom in, the more difficult it is to keep the picture steady. In some cases you can move the camera closer to the subject and then zoom out so you have basically the same framing. For long zooms you should use a tripod. Zooming is the function everyone loves. It's easy and you can do lots with it, which is why it's so over-used. The most common advice we give on using the zoom is use it less. It works well in moderation but too much zooming is tiring for the audience.

2 TYPES Manual zoom (ring). This is a zoom ring on the lens housing which is rotated manually, typically by the left thumb and index finger. Advantages: Speed (you can do super-fast zooms); doesn't require power (so no drain on your battery). Disadvantages: More difficult to control; harder to get smooth zooms. Servo zoom (lever). This is a lever which sits on the lens housing. It's usually positioned so that when you slide your right hand into the grip belt, the servo zoom will be sitting under your first two fingers. Pressing the front part of the lever zooms in, pressing the rear part zooms out. Cheaper cameras usually have a constant zoom speed, whereas a good servo zoom will have variable speed -- the further you depress the lever, the faster the zoom. The lever may have labels such as T and W (tele and wide). Advantages: Easy to use in most situations; nice smooth zooms. Disadvantages: Uses battery power; may be limited to fixed speeds.

There's an important characteristic of zoom lenses that you should be aware of: The further you zoom in, the more difficult it is to keep the picture steady. At very long zooms, a tripod is essential. If you're having trouble keeping your shot steady, it may be possible to move yourself closer to the subject and then zoom out. This way you'll have essentially the same framing, but much steadier. Zooming is the function everyone loves. It's easy and you can do lots with it, which is why it's so over-used. The most common advice we give on using the zoom is use it less. It's a great tool in moderation, but when most of your shots are zooming in and out, your audience will feel nauseous.

DIGITAL V OPTICAL Digital Zoom This is often trumpeted as a big selling point by manufacturers. It's common to see a large "150X" emblazoned on the side of a camcorder. Video stores are full of naive customers comparing the digital zoom of different cameras. Do not be fooled! Digital zoom is all but irrelevant. It only exists as a marketing ploy to trap unsuspecting newbies. Ignore this spec completely, and if a salesperson tries to impress you with it, find another salesperson. Digital zoom works by magnifying a part of the captured image using digital manipulation. This is the same as how a graphics program resizes an image to a larger size. The process involves taking a certain number of pixels and creating a larger image, but because the new image is based on the same number of pixels, the image loses quality. At small zooms (up to 20x) the loss may not be too noticeable. At large zooms (up to 100x or more) the quality becomes absolutely terrible. Some digital zooms use interpolation, which is a way of estimating the value of the new pixels rather than simply duplicating existing pixels. In theory this should reduce the loss of quality, but no amount of interpolation will prevent loss altogether. Remember that digital zoom can be done in post-production with any half-decent editing software, so you really gain nothing by having the camera do it.

Optical Zoom This is the zoom spec which matters. Optical zoom is provided by the lens (i.e. the optics) and does not lose image quality. The zoom is provided by a telephoto lens. Most consumer camcorders come with optical zooms of between 10x and 20x. 10x is adequate for most applications. More is usually better — 20x should be ample for all but the most demanding zoom users.