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How Camcorders Work
by ahmad reza tabatabaiyan
Camcorders let you record everything from your child's birthday to documentary films, and the features on the newest camcorders are amazing! Learn exactly how they work and what to look for if you are thinking about purchasing one!
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دوربین فیلمبرداری ویدئو و تلویزیون (سبک و قابل حمل با یک دست)
دوربین فیلمبرداری ویدئو و تلویزیون آنالوگ، دارای دو بخش اصلی است یکی خود دوربین ویدئویی و دومی VCR یا دستگاه ضبط نوار ویدئویی. بخشی از یک فیلم یا عکس را گرفته و آن را بعنوان یک سیگنال ویدئویی الکترونیکی بر می گرداند. بعد VCR یا دستگاه ضبط نوار ویدئویی، سیگنال ویدئو الکترونیکی را دریافت کرده و آن را در روی نوار ویدئو ضبط می کند. بخش سوم این دوربین، قسمت منظره یاب یا نمایاب آن است، بدین طریق که تصاویر ویدئویی را دریافت کرده طوریکه می توانید آنچه را که فیلمبرداری یا عکسبرداری کردید، ببینید. منظره یا بهای جدید دارای صفحه نمایش کریستالی مایعی تمام رنگ بزرگی هستند. دوربینهای دیجیتالی هم دارای اجزائی همانند دوربین های آنالوگی می باشند اما این دوربینها، اطلاعات را گرفته، آن را به بایتهای اطلاعاتی تبدیل می کنند و تصاویر و صداها را بعنوان اعداد یک و صفر ضبط می کنند. اطلاعات ویدئویی در دوربینهای دیجیتالی در کامپیوترها می توانند بارگذاری شوند بطوریکه می توانید آن را email، کپی و یا حتی مونتاژ کنید. چنین دوربینهایی برای عکس گرفتن از دستگاه تزویج بار، یا "سی سی دی" استفاده می کنند. در این نوع دوربین ها، دو نوع زوم کردن وجود دارد یکی نوری یکی دیجیتالی،. زوم نوری از لنز استفاده می کند تا یک تصویر را بزرگ نما کند که در اینجا از دریافتگر تصویر سی سی دی استفاده می شود. اما زوم دیجیتالی به سادگی تصویر گرفته شده را از سی سی دی بزرگ نما می کند که سایز پیکسل را افزایش می دهد.
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In most of the world, camcorders, or video camera-recorders, have been a familiar sight for nearly 20 years. People take them everywhere: to school plays, sports events, family reunions and even births! When you go to a popular tourist spot, you are surrounded by them. Camcorders have really taken hold in the United States, Japan and many other countries around the world because they are an extremely useful piece of technology that you can own for under $500.
How can such a small, relatively inexpensive device do so much? Particularly for anyone born before the 1980s, it's simply amazing that quality video cameras are now readily available as consumer items, and that they're so easy to use. In this edition of How Stuff Works, we'll look inside these extremely popular devices to find out what exactly is going on. We'll explore traditional analog camcorders and also look at the technology used in the new digital camcorders. The following map will lead you to all the different parts:
You may want to start with How They Work to learn how camcorders work -- they are amazing devices! If you've never used a camcorder before or if you are curious about the differences between analog and digital camcorders, try What They Can Do. Features tells you about all of the features you find on modern camcorders so you know what you are talking about if you are looking to buy one. And so on... Just click on the different areas of the map to learn all about these amazing devices!
How They Work
As the name suggests, a basic analog camcorder has two main components:
The camera component's function is to receive visual information and interpret it as an electronic video signal. The VCR component is exactly like the VCR connected to your television: It receives an electronic video signal and records it on video tape as magnetic patterns (see How VCRs Work for details). A third component, the viewfinder, receives the video image as well, so you can see what you're shooting. Viewfinders are actually small, black-and-white or color televisions, but many modern camcorders also have larger full-color LCD screens. There are many formats for analog camcorders, and many extra features, but this is the basic design of most all of them. The main variable is what kind of storage tape they use.
Digital camcorders have all these same elements, but have an added component that takes the analog information the camera gathers and translates it to bytes of data. Instead of storing the video signal as a continuous track of magnetic patterns, it records the picture and sound as ones and zeros. Digital camcorders are so popular because you can copy ones and zeros very easily without losing any of the information you've recorded. Analog information, on the other hand, "fades" with each copy -- the copying process doesn't reproduce the original signal exactly. Video information in digital form can also be loaded onto computers, where you can edit it, copy it, e-mail it and manipulate it (editing digital video is discussed in detail on this page).
Let's take a look at the how the camera component of a camcorder works. [For a full explanation on how a camcorder actually takes an analog signal from the camera and records on tape, check out How VCRs Work.]
The CCD
Like a film camera, a camcorder "sees" the world through lenses. In a film camera, the lenses serve to focus the light from a scene onto film treated with chemicals that have a controlled reaction to light. In this way, camera film records the scene in front of it: It picks up greater amounts of light from brighter parts of the scene and lower amounts of light from darker parts of the scene. The lens in a camcorder also serves to focus light, but instead of focusing it onto film, it shines the light onto a small semiconductor image sensor. This sensor, a charge-coupled device (CCD), measures light with a half-inch (about 1 cm) panel of 300,000 to 500,000 tiny light-sensitive diodes called photosites.
Each photosite measures the amount of light (photons) that hit a particular point, and translates this information into electrons (electrical charges): A brighter image is represented by a higher electrical charge and a darker image is represented by a lower electrical charge. Just as an artist sketches a scene by contrasting dark areas with light areas, a CCD creates a video picture by recording light intensity. During playback, this information directs the intensity of a television's electron beam as it passes over the screen.
Figure 1. Photons hitting a photosite and creating electrons
Of course, measuring light intensity only gives us a black-and-white image. To create a color image, a camcorder has to detect not only the total light levels, but also the levels of each color of light. Since you can produce the full spectrum of colors by combining the three colors red, green and blue, a camcorder actually only needs to measure the levels of these three colors to be able to reproduce a full-color picture.
Figure 2. How the three colors mix to form many colors
In some high-end camcorders, a beam splitter separates a signal into three different versions of the same image -- one showing the level of red light, one showing the level of green light and one showing the level of blue light. Each of these images is captured by its own chip -- the chips operate as described above, but each measures the intensity of only one color of light. The camera then overlays these three images and the intensities of the different primary colors blend to produce a full-color image. A camcorder that uses this method is often referred to as a three-chip camcorder.
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Figure 3. How the original (left) image is split in a beam splitter
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This simple method produces a rich, high-resolution picture. CCDs are expensive and eat lots of power, however, so using three of them adds considerably to manufacturing costs of a camcorder. Most camcorders get by with only one CCD by fitting permanent color filters to individual photosites. A certain percentage of photosites only measure levels of red light, another percentage measures only green light and the rest measure only blue light. The color designations are spread out in a sort of grid (the Bayer filter below is a common configuration), so that the video camera computer can get a sense of the color levels in all parts of the screen. This method requires the computer to interpolate the true color of light arriving at each photosite by analyzing the information received by the other photosites in the vicinity. For a full explanation of this process, check out this page.
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Figure 5. A Bayer Filter
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If you've read How a Digital Camera Works, then all this has probably been familiar to you -- camcorders and digital still cameras both take pictures using CCDs. But since camcorders produce moving images, their CCDs have some additional pieces you won't find in digital camera CCDs. To create a video signal, a camcorder CCD must take many pictures every second, which the camera then combines to give the impression of movement.
If you've read How Television Works, you know that a television "paints" images in horizontal lines across a screen, starting at the top and working down. TVs actually paint every other line in one pass (this is called a field) and then paint the alternate lines in the next pass. To create a video signal, a camcorder captures a frame of video from the CCD and records it as the two fields. The CCD actually has another sensor layer behind the image sensor. For every field of video, the CCD transfers all the photosite charges to this second layer, which then transmits the electric charges at each photosite, one by one. In an analog camcorder, this signal goes to the VCR which records the electric charges (along with color information) as a magnetic pattern on videotape. While the second layer is transmitting the video signal, the first layer has refreshed itself and is capturing another image.
A digital camcorder works in basically the same way, except at this last stage an analog-to-digital converter samples the analog signal and turns the information into bytes of data (ones and zeros). The camcorder records these bytes on a storage medium, which could be, among other things, a tape, a hard disk or a DVD. Most of the digital camcorders on the market today actually use tapes (because they are less expensive), so they have a VCR component much like an analog camcorder's VCR. Instead of recording analog magnetic patterns, however, the tape head records binary code. Interlaced digital camcorders record each frame as two fields, just as analog camcorders do. Progressive digital camcorders record video as an entire still frame, which they then break up into two fields when you output the video as an analog signal. To learn more about analog-to-digital picture conversion, check out this page from How Digital Cameras Work or this article about the difference between analog and digital recording.
The Lens
As mentioned above, the first step in recording a video image is to focus light onto the CCD, using a lens. To get a camera to record a clear picture of an object in front of it, you need to be able to adjust the focus of the lens, that is, move the lens so it aims the light beams coming from that object precisely on the CCD. So, just like film cameras, camcorders let you move your lens in and out to focus light. Of course, most people need to move around with their camcorders, shooting many different things at different distances, and constantly refocusing is extremely difficult.
This is why all camcorders come with an auto focus device, usually an infrared beam that bounces off objects in the center of the frame and comes back to a sensor on the camcorder. To find the distance to the object, the processor calculates how long it took the beam to bounce and return, multiplies this time by the speed of light, and divides the product by two (because it traveled the distance twice -- to the object and back again). The camcorder has a small motor that moves the lens, focusing it on objects at this distance. This works pretty well most of the time, but sometimes you have to override it -- you may want to focus on something in the side of the frame, for example, but the auto focus will pick up what's right in front of the camcorder. To learn more about auto focus mechanisms, check out How Autofocus Cameras Work.
Camcorders are also equipped with a zoom lens. In any sort of camera, you can magnify a scene by increasing the focal length of the lens (the distance between the lens and the film or CCD). An optical zoom lens is a single lens unit that lets you change this focal length, so you can move from one magnification to a closer magnification. A zoom range tells you the maximum and minimum magnification. To make the zoom function easier to use, most camcorders have an attached motor that adjusts the zoom lens in response to a simple toggle control on the grip. One advantage of this is that you can operate the zoom easily, without using your free hand. The other advantage is that the motor adjusts the lens at a steady speed, making zooms more fluid. The disadvantage of using the grip control is that the motor drains battery power.
Some camcorders also have something called a digital zoom. This doesn't involve the camera's lenses at all; it simply zooms in on part of the total picture captured by the CCD, magnifying the pixels. Digital zooms stabilize magnified pictures a little better than optical zooms, but you sacrifice resolution quality because you end up using only a portion of the available photosites on the CCD. The loss of resolution makes the image fuzzy.
One of the great things about a camcorder is that it can adjust automatically for different levels of light. It's very obvious to the CCD when an image is over- or under-exposed because there won't be much variation in the charges collected on each photosite. The camcorder monitors the photosite charges and adjusts the camera's iris to let more or less light through the lenses. The camcorder computer always works to maintain a good contrast between dark and light, so that images don't appear too dark or too washed out.
Summary
Camcorders are amazing, but they perform a fairly straight-forward task -- they simply convert visual information into an electronic signal (or a string of bytes) and encode it on tape. What's most remarkable about them is that they combine several complex devices into one small package. As we've seen, a camcorder has:
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A traditional camera mechanism, with a zoom lens and automatic aperture
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A CCD that converts light into electronic signals
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A microphone that records audio along with the visual information
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A small television or LCD screen that plays these signals
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In digital camcorders, an analog-to-digital converter
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A VCR that records the video signal on tape
Essentially, a camcorder is a simple television studio that you can carry in the palm of your hand! As technology has developed over the years, manufacturers have continually added more useful components to camcorder designs, expanding functionality and increasing user-friendliness. With new digital technology and rapid advancements in computer technology, this trend is sure to continue. Who knows what will be available to the average consumer in 10 years?
What They Can Do
Camcorders have been available for 20 years already, but most of us have only scratched the surface of their potential. If you haven't paid much attention to how camcorders have progressed over the years, you'll be amazed at what you can do with the newest units. The new wave of digital camcorders is a home technology breakthrough comparable to the initial appearance of home video cameras two decades ago.
Let's explore the difference between analog and digital cameras, and see what you can do with the two formats. We'll explain what computers have to do with digital cameras and learn about the capabilities of consumer movie-editing software. If you've been wondering why everybody's so excited about digital camcorders these days, we'll help get you up to speed.
The Advantages of Video
When VCRs first came out, camcorders were a natural choice for a companion device. They filled the same need as inexpensive, 8-mm movie camerasof the 1960s and 1970s, and offered some major improvements. For one thing, a camcorder allows you to see your movie immediately, while 8-mm cameras use film that has to be sent off to a developer. Videotape is much cheaper than film, so you don't have to be so selective with what you shoot. For a couple of dollars, you can buy a two-hour VHS tape, which you can record over many times. Video still doesn't produce the same rich picture (or resolution) as film, however, and most amateur and professional movie-makers still swear by 16-mm or 32-mm film for its many qualities.
You can do all sorts of things with video that you can't do with film because the two media work in completely different ways. Film is a very physical medium: When you film a movie, you are simply capturing a series of pictures on specially treated strips of material. You develop this film to produce another strip of still images that you can run through a projector. Video, on the other hand, is an electronic signal. Once you have that analog signal recorded, it's very easy to transmit video between different electronic devices, whether to make copies or simply play your movie on a television.
Another impressive quality of video is that you can shoot in a wide range of lighting conditions. Everybody knows that you need a good amount of light to take a good picture with a film camera. This is why you usually need a flash for indoor photography. The CCD in a camcorder, on the other hand, allows you to record good-looking video by the light of one candle. In most lighting conditions, a camcorder can also automatically adjust its aperture so that it doesn't over- or under-expose the picture. Even if the lighting conditions around you are changing rapidly, you don't have to do anything but point and shoot. This quality helps make camcorders remarkably easy-to-use.
The chief advantages of video, then, are that it is a versatile, easily transmitted medium and that it adapts very well to different lighting conditions. These qualities let camcorder manufacturers automate and simplify many of the tasks involved in shooting and recording video, making camcorders extremely user-friendly devices. In the next section, we'll look at some of those standard features manufacturers include with their camcorders.
Standard Camcorder Features
Along with the basic camcorder components -- the video camera, onboard VCR, microphone and viewfinder -- you'll typically find:
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A simple record button: When you hold the camcorder by the grip, your thumb will rest on the record button. All you have to do to switch the record mode on and off is press the button. This acts as a sort of pause on recording, so that you begin recording at the exact spot on the tape that you stopped recording.
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A zoom function: This lets you magnify images that are farther away from you. Zooms are operated with a simple toggle control on the camcorder grip.
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Auto focus: The camcorder senses where objects are in front of it and adjusts the focus accordingly
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VCR controls: These controls let you operate your camcorder just as you would a standard VCR.
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Battery and AC adapter: Camcorders come with a rechargeable battery and a power cord that attaches to a standard outlet.
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Audio dub: On most camcorders, you can record new audio over video you have already shot.
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Fade-in and fade-out: Often, this function works by simply underexposing or overexposing the image to the point that the entire screen is black or white.
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Clock: If you program the correct time and date, the camcorder can display it on your recorded video.
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Headphone jack: This is a useful feature because it lets you monitor sound quality as you shoot or when you review footage using the onboard VCR.
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External microphone input: In some situations, you may want to attach a specialized microphone, such as a boom or a lapel mic, in place of the attached microphone.
Copying and Editing Video
One great thing about video is that you can transmit it very easily between electronic devices. To make a copy of a video tape, all you need to do is connect two VCRs together, play your tape on one and press record on the other. The camcorder itself has an onboard VCR, so if you have a camcorder and a VCR, you have all you need to make copies. You can also edit video this way, but VCRs are not designed for this so it's very difficult to make precise, clean cuts.
The other problem with editing and copying this way is that every time you make an analog copy, you "lose a generation," meaning the quality of the image and sound deteriorates. There is a noticeable difference between an original and a direct copy, and if you were to make a copy of a copy, you'd really be able to see the effect. This is because when you make an analog video copy, you're not making a direct reproduction of the magnetic patterns on the video tape, but actually decoding those patterns into a video signal, sending the signal to another VCR that then re-records the signals as magnetic patterns. Every time a device reinterprets the video signal, the signal changes a little bit, and so the picture quality degrades.
Even with a simple setup using two VCRs, your second-generation copy will still look pretty good. Very few people bother to edit their home movies this way, however, because the process is so cumbersome and the results usually look fairly messy. Up until recently, quality video-editing equipment was too big an investment for the casual video-maker, and most units could easily fill a small room. Consequently, most people with analog camcorders have boxes of tapes with hours of choppy, unedited footage, which they rarely watch. This is too bad because it means the typical camcorder-owner has been missing out on one of the most rewarding elements of making home-movies -- assembling footage into a finished work.
In recent years, however, manufacturers have changed all this with the advent of affordable digital camcorders. With digital camcorders, you can download video footage to your computer, edit it with easy-to-use, inexpensive software (some camcorders and home computers actually include basic editing programs as part of their software package) and copy it back to tape with virtually no loss in image quality.
With editing capabilities, camcorder owners can create polished home movies, ones that they'll actually feel like watching from time to time. This expands the functionality of the camcorder a great deal, allowing consumers to make impressive school presentations, documentaries, training videos, concert movies and many other interesting projects.
Digital Video
One of the chief advantages of digital video, then, is that you can edit it on a computer. To do this, however, you have to have some way of getting the video onto your computer. Digital camcorders are outfitted with a FireWire (IEEE 1394) port that transmits streaming video very quickly. Many newer computers also have FireWire ports, but to use this connection on an older computer you may have to install a FireWire card and port.
No matter what kind of connection you use, you'll need a software application that can receive digital video. Most digital camcorders are packaged with this software, but you need to make sure the program is compatible with your operating system (Windows, Mac OS, etc.). You'll also need a computer program that will let you edit digital video. There are all sorts of software applications available, and even the simplest ones will let you cut scenes, rearrange sequences and add titles. Your camcorder may come with a simple program, and many new computers now have an editing application included in their introductory software package. Higher-end applications let you apply special effects to your video, such as interesting filters or distortions. Digital video is fairly easy to manipulate, in the same way that digital photographs are easily modified in a computer. All this requires a pretty fast computer with a lot of memory and hard drive space, so you may not be able to use your camcorder this way if you have an older computer. A digital camcorder is still a good investment, however, because there's a good chance that the next time you buy a computer, it will already be configured to receive digital video.
If you've already been recording analog video for years and years, a digital camcorder can help you finally edit it into something you'll want to watch. Your original camcorder and a digital camcorder with audio-video input jacks gives you everything you need to convert analog footage to digital. All you need to do is connect a VCR or your old camcorder to your new camcorder, using standard audio-video cables (commonly called RCA cables). Hit Play on the analog VCR and Record on the digital camcorder, and you'll have a digital copy in no time. You'll lose one generation in the conversion process, of course, but after that the footage is in digital form and so won't degrade any further. You can then edit it just as you would any other digital footage.
The other main advantage of digital video is that once you download it to your computer, it is stored as a basic computer file. This means you can e-mail your movies, post them on the Internet or simply store them on your hard drive. Keep in mind that digital video files are quite large, and that you'll probably need to upload small portions of your footage at a time and then upload your finished movies back to tape for permanent storage.
Many digital camcorders will also let you select still pictures out of your footage, effectively making them a camcorder and digital still camera in one. In fact, some camcorders have an option for taking digital pictures and storing them on a flash memory device, just as a digital camera does. Digital camcorders have a fairly high picture resolution, so these pictures will come out well, but they will not have as high a resolution as pictures taken with a high-end digital camera.
Summary
With the rise of digital video and the increasing speed and performance of computers, the ability to make complete, polished video productions is now within the average consumer's reach. A fast personal computer and a digital camcorder are all you need to produce your own television show! If your city has a cable access station, you can even get it on the air.
This is really amazing when you consider what movie-making equipment was available to the average consumer even 25 years ago. Very few amateurs had access to video equipment, and film was expensive and relatively difficult to manage. You could edit it, with a simple splicer machine, but this required a lot of skill and patience. It wasn't something you could take up casually.
These days, you can get a digital camcorder for $700 and pick up some tapes for under $10. Digital video editing programs simplify the editing process to the point where you can master it in an afternoon. Camcorders have so many helpful features that anybody can get decent footage with a little practice and you can create quality movies with more in-depth studying. The technology that was once the exclusive domain of television professionals is now available as hobby equipment. Whether you simply want to record birthday parties and recitals, or you hope to produce ambitious video projects, the newest camcorders have a lot to offer.
Features
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Formats |
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Feature |
Option |
Description |
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Analog |
Standard VHS |
VHS cams use regular VCR tapes, which are a lot less expensive than the tapes used in other formats; they also give you a longer recording time, two to four hours. But the size of the tapes necessitates a more cumbersome camcorder design. They have a resolution of about 230 to 250 horizontal lines, the low end of what's now available. |
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VHS-C |
VHS-C cams use standard VHS tapes housed in more compact cassettes -- you need an adaptor to play them on a regular VCR. The smaller tape size allows for more portable designs, but they have a much shorter recording time than standard VHS -- 30 to 90 minutes. |
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Super VHS |
Super VHS cameras are about the same size as standard VHS cameras, because they use the same size tapes, also with two to four hours of recording time. But a super VHS tape records an image with 380 to 400 horizontal lines, a much higher resolution image. To watch a super VHS tape on your TV, you have to use your camcorder as the VCR or purchase a super-VHS VCR. |
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Super VHS-C |
Basically, super VHS-C is a more compact version of super VHS, using a smaller size cassette, with 30 to 90 minutes of recording time and 380 to 400 resolution. |
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8 mm |
These cameras use 8-mm tapes (about the size of an audio cassette), allowing for extremely compact design. 8 mm offers about the same resolution as standard VHS, with slightly better sound quality. Like standard VHS tapes, 8-mm tapes hold two to four hours of footage, but they are more expensive. To watch 8-mm tapes on your television, you have to use your camcorder as the VCR. |
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Hi-8 |
Hi-8 cameras are very similar to 8 mm, but they have a much higher resolution (about 400 lines). Hi-8 tapes are more expensive than ordinary 8-mm tapes and they hold about two to four hours of footage. |
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Digital |
Digital Video (DV) |
DV cameras record on compact mini-DV cassettes, which are fairly expensive and only record 60 to 90 minutes. DV has 500 lines of resolution, and can be transferred easily to a PC. They're extremely lightweight and compact, and have the ability to capture still pictures. |
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Digital 8 |
Digital 8-cameras (Sony exclusive) are similar to regular DV cameras, but they use standard 8 mm tapes, which are a less expensive, and hold up to 60 minutes of footage that can be copied without any loss in quality. Digital 8 cameras connect easily to your computer with a firewire connection. They are a bit larger than DV camcorders. |
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Key Features |
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Feature |
Option |
Description |
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Viewfinder |
Black/White Eyepiece |
This provides a very small black-and-white screen, viewed through a portal, where you can see exactly what you are taping. |
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Color Viewfinder |
The only difference between this and the black-and-white eyepiece is the color, which provides a more accurate depiction of what you are recording. If you plan on using any special effects, you'll probably want to go for the color. |
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LCD Screen |
With this feature, you can watch the color LCD screen instead of viewing through the eyepiece (some models provide both). The screen can usually swivel, to adjust your viewing angle. But LCDs do use more power than a simple eyepiece, so it could decrease your battery life. |
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Zoom |
Optical Zoom |
Optical zoom changes the size of the object in view without moving the camcorder. Usually limited to 24x, the larger the optical zoom number the more flexibility you have when shooting. A high number is especially important if your cam's lens is not detachable and you want some control over your shooting. |
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Digital Zoom |
Digital zoom uses the cam's processor to expand an image beyond optical zoom capabilities (up to 300x). But using this feature can degrade image quality, so for clear images you'll want to turn this feature off (note: the higher the optical zoom number, the clearer the digital zoom image). |
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Power Source |
Batteries |
Nickel-cadmium batteries are pretty standard, and allow for one to two hours of recording time before they need to be recharged. Smaller or higher-end cameras may use proprietary batteries specific to the manufacturer, and this can make extra or replacement batteries expensive. Check the battery technology and prices before you buy a camera. |
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AC Adapter |
AC adapters can be used to supply power to the camcorder whenever you are near an electrical outlet. This saves the battery for times when you are without an external power source. |
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Car Adapter |
If you plan on using your camcorder in or near your vehicle, you might want to buy a car adapter to save some battery power on those occasions. |
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Light |
Standard |
Most camcorders do quite well in low-light conditions without help from additional lights. As long as you don't plan on filming primarily in indoor or low-light conditions, you do not necessarily need supplementary light. |
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Built-in Light |
Some cameras come with a built-in light source, and many can be programmed to turn on automatically when conditions require additional light. |
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External Connectivity |
Some cameras allow you to connect an external light source to the unit, for greater control over lighting conditions. |
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Image Stabilization |
Electronic Stabilization |
This feature electronically stabilizes the image being filmed, but can decrease its clarity. |
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Digital Stabilization |
This feature does the same kind of stabilization, only it uses digital technology, and can also correct for tilting and panning movement -- again, this feature can decrease image quality. |
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Optical Stabilization |
Uses a series a lenses to reduce shake, optical stabilization decreases the effects of camera movement and vibration on the image being filmed -- very important with handheld cameras and when filming a moving object. Not common on inexpensie camcorders. |
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CCD Chips |
One Chip |
Most cameras use a single CCD chip to capture and transmit image information. Look for size and pixel specifications, the higher the better. |
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Three Chip |
Some high-end cameras use three chips to enhance colors and provide better resolution. Three-chip cameras capture more information than one-chip cameras, and can capture and transmit colors with greater accuracy. This is an expensive feature found only on high-end and professional cameras. |
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Exposure Modes |
Automatic |
Most cameras will set the proper exposure mode for the conditions you are filming in. If you are strictly amateur and don't feel the need to alter the exposure, automatic settings will suit you just fine. |
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Semi-manual |
Some cameras allow you to adjust the exposure for certain conditions, such as low light, backlight or motion. |
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Manual |
If you want to be able to control all aspects of exposure and focus to fit your creative vision, look for a camera that allows you to adjust these settings freely. |
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Microphone |
Built-in |
Most camcorders come with a built-in microphone to record sound. Unless you plan on professional use, this standard feature will suit your needs very well. |
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External Connectivity |
If you need professional sound quality, look for a camera that allows you to attach an external microphone. |
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Camera Control |
Automatic |
Some camcorders automatically adjust everything -- for amateur movie makers, these settings will be more than satisfactory. |
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Manual |
For professional use, or if you just want greater control over the look of your video, you probably want a camcorder that allows you to adjust the various settings on your own. Look for manual exposure control, manual focus, manual zoom, manual white balance and so on. |
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Extras |
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Feature |
Description |
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Still Image Capability |
Digital camcorders let you pick still images out of your video. Camcorders with a built-in or removable memory device let you take still pictures as you would with a digital still camera. |
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Detachable Lens Adapter |
If you want to be able to switch the lens on your camcorder depending on conditions, look for one with a detachable lens adapter. For example, A wide-angle lens attachment is a common accessory to buy if you shoot lots of video indoors in small rooms. |
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Low-Light Responsiveness |
Camcorders come with specifications regarding the minimum recommended level of light during recording. The higher this LUX number, the more light you need. If a camcorder specifies 0 LUX, it can see images in complete darkness. |
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Progressive Scan |
Only available in digital formats, progressive scan records an image with a single scan pass instead of as odd and even fields, increasing the quality of the image. This technology is especially important if you plan to use your camcorder to take still pictures. |
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Analog Video Input |
If you want to be able to convert your existing VHS format tapes to digital format, for editing or viewing purposes, look for a digital camcorder that allows for analog input. |
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16x9 Recording Mode |
This is "wide-screen" recording mode -- if you plan on viewing your handiwork on a widescreen TV, look for a camcorder that supports 16x9 format (such a camera will also support regular mode). |
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Audio Recording Formats |
Most digital camcorders can support both 32 kHz 12 bit and 48 kHz 16 bit audio formats. 48 kHz 16 bit audio is better than CD quality, so if you need REALLY amazing sound to go with your video, this is the format for you. |
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IEEE 1394 (FireWire, i.Link) Compatibility |
Most of the newer digital camcorders come with IEEE 1394 compatibility, which is basically a way of connecting the camcorder to your computer for extremely fast downloading. Not all computers are FireWire compatible, and not all camcorders use the exact same FireWire technology, so be sure to check out specifications in both areas before choosing a model. |
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Playback Features |
Almost all camcorders come with VCR-type features like rewind, play and pause -- just make sure to find a camcorder with the playback features you're looking for, because they do vary. |
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Special Effects |
Some of the higher-end camcorders come with special effects features, such as fade-in/fade-out, and special recording modes like sepia or negative. |
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Motion/Audio Sensing |
Some camcorders have special sensors that turn the camera on in the presence of movement or sound. This is generally only useful for security purposes. |
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When You Shop
We've created a Camcorder Feature Comparison chart for you to use as you research various models. Take it to the store with you and fill in the blanks for each model you are interested in. You may also want to keep an additional copy near your desk as you research camcorders on the Internet.
The feature comparison chart is available to you as a PDF. You will need the free Adobe Acrobat Reader to view it.
To give you an example of some typical camcorders, here are 10 popular models:
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Panasonic VHS-C Camcorder
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![]() ![JVC Digital Camcorder]()
JVC Digital Camcorder
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![]() ![Sharp Hi8 ViewCam« Camcorder]()
Sharp Hi8 ViewCam Camcorder
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Panasonic PV-L650 Camcorder
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Sony CCD-TRV87 Hi8 Camcorder
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RCA CC6263 VHS-C AutoShot Camcorder
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JVC GRDVF31 Digital Camcorder with 3" TFT LCD Display
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Sony CCD-TRV57 8mm Camcorder
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![Panasonic Digital Camcorder]()
Panasonic Digital Camcorder
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![]() ![Panasonic Digital Camcorder]()
Panasonic Digital Camcorder
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Formats
One of the more difficult tasks involved in shopping for a camcorder is choosing between all the available formats. This list will tell you how each format is different from the others and give you the main advantages and disadvantages of each variety. One distinction between different camcorder models is whether they are analog or digital, so we have divided this list into those two categories.
Analog
Analog camcorders record video and audio signals as an analog track on video tape. This means that every time you make a copy of a tape, it loses some image and audio quality. Analog formats lack a number of the impressive features you'll find in digital camcorders, as described in the digital cameras section below. The main difference between the available analog formats is what kind of video tape the camcorder uses and the resolution. Analog formats include:
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Standard VHS:
Standard VHS cameras use the same type of video tapes as a regular VCR. One obvious advantage of this is that after you've recorded something, you can pop the tape out and play it on most VCRs. Because of their widespread use, VHS tapes are a lot less expensive than the tapes used in other formats. Another advantage is that they give you a longer recording time than the tapes used in other formats. The chief disadvantage of standard VHS format is that the size of the tapes necessitates a larger, more cumbersome camcorder design. They have a resolution of about 230 to 250 horizontal lines, which is the low end of what's now available.
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VHS-C:
VHS-C camcorders record on standard VHS tape that is housed in a more compact cassette. You can play VHS-C cassettes in a standard VCR, but you need an adaptor device that runs the tape through a full-size cassette. Basically, though, VHS-C format offers the same compatibility as standard VHS format. The smaller tape size allows for more compact designs, making VHS-C camcorders more portable. But the reduced tape size also means VHS-C tapes have a shorter running time than standard VHS cameras. In short play mode, the tapes can hold 30 to 45 minutes of video. They can hold 60 to 90 minutes of material if you record in extended play mode, but this sacrifices image and sound quality considerably.
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Super VHS:
Super VHS camcorders are about the same size as standard VHS cameras, because they use the same size tapes. The only difference between the two formats is that super VHS tape records an image with 380 to 400 horizontal lines, a much higher resolution image than standard VHS tape. You cannot play super VHS tapes on a standard VCR, but, as with all formats, the camcorder itself is a VCR and can be hooked up directly to your television or to your VCR to dub standard VHS copies.
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Super VHS-C:
Basically, super VHS-C is to super VHS as VHS-C is to standard VHS: It's just a more compact version that uses a smaller size cassette.
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8 mm:
These camcorders use small 8-millimeter tapes (about the size of an audio cassette). The chief advantage of this format is manufacturers can produce more compact camcorders, sometimes small enough to fit in a coat pocket. The format offers about the same resolution as standard VHS, with slightly better sound quality. Like standard VHS tapes, 8 mm tapes hold about two hours of footage, but they are more expensive. To watch 8 mm tapes on your television, you have to attach your camcorder and use it as a VCR.
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Hi-8:
Hi-8 camcorders are very similar to 8 mm camcorders, but they have a much higher resolution (about 400 lines). Hi-8 tapes are more expensive than ordinary 8 mm tapes.
Digital
Digital camcorders differ from analog camcorders in a few very important ways. They record information digitally, as bytes, which means that image can be reproduced without losing any image or audio quality. Digital video can also be downloaded to a computer, where you can edit it or post it on the Web. Another distinction is that digital video has a much better resolution than analog video, typically 500 lines. There are two consumer digital formats in widespread use:
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Digital Video (DV):
DV camcorders record on compact mini-DV cassettes, which are fairly expensive and only hold 60 to 90 minutes of footage. The video has an impressive 500 lines of resolution, however, and can be easily transferred to a personal computer. DV camcorders can be extremely lightweight and compact -- many are about the size of a paperback novel. Another interesting feature is the ability to capture still pictures, just as a digital camera does.
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Digital 8:
Digital-8 camcorders (produced by Sony exclusively) are very similar to regular DV camcorders, but they use standard Hi-8-mm tapes, which are less expensive. These tapes hold up to 60 minutes of footage, which can be copied without any lose in quality. Just as with DV camcorders, you can connect Digital-8 camcorders to your computer to download your movies for editing or Internet use. Digital-8 cameras are generally a bit larger than DV camcorders -- about the size of standard 8-mm models.
Look Out!
You will want to keep the following points in mind as you are shopping for a camcorder:
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What format?
See this page for a good description of all the different formats. If you're shopping for a camcorder, you need to carefully consider which camcorder format you want before you even enter the store. The main thing to consider is whether or not you want an analog or digital camcorder. Analog camcorders work well and are often half the price of digital camcorders, but they are a dying technology. If you only want to tape special events occasionally and keep the footage in unedited form, an analog camcorder might be fine for you. If you think in the future you might possibly be interested in editing your videos, e-mailing them or posting them on the Web, you need to get a digital camcorder. Also consider that digital video, once saved to a hard drive, does not degrade in quality over the years as taped analog footage does.
Whether you're looking for an analog camcorder or a digital camcorder, make sure the particular format you choose will meet your needs. One thing to look out for is the cost of tapes. Mini DV camcorders, for example, may promise a slightly better picture than Digital 8 camcorders but their tapes are significantly more expensive. Other factors to consider when choosing a format are image resolution, sound quality and tape length.
See this page for a good description of all the different formats.
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Zoom capability
There are two kinds of zoom options for camcorders: optical zooms and digital zooms. Optical zooms actually use lenses to magnify an image, so a zoomed picture will use the maximum resolution of the camcorder's CCD image sensor. Digital zooms simply magnify the captured image from the CCD, effectively increasing pixel size. This blows up the picture but decreases image resolution. Optical zooms, therefore, are the better option.
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IEEE 1394 (FireWire) Port
Most digital camcorders have an IEEE 1394 port for downloading video to your computer, but a few do not. If you're buying a digital camcorder, you should be absolutely sure it has an IEEE 1394 port. Also, look for a camcorder that comes packaged with the necessary software for capturing video, and make sure this software is compatible with the computer you plan to use.
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Battery Power
This is a very important feature. Make sure the battery life is suitable for your needs and find out how much extra batteries cost. Another thing to consider is how long it takes to recharge the battery. If you plan to use your camcorder outside a lot, then these battery capabilities are extremely important.
Where to Buy
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Camera Club
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![]() 800.COM -
Amazon
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J&R Music World
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uBid![]()
FAQ
Up until recently, all consumer camcorders were analog, meaning they recorded video signals as a steady wave of magnetic patterns. Digital camcorders convert this analog video into digital data (bytes of information) by sampling many very small pieces of the signal. The advantage of this is that bytes, which are only a series of ones and zeros, can be reproduced exactly the same way any number of times, while analog signals have to be reinterpreted every time you copy them. Analog video decreases in quality every time you copy it -- also every time you play it, though this is a very slow deterioration. You can copy digital video as many times as you want and you can store it on your computer forever without its quality degrading. Digital video is also popular because you can edit it on a computer, send it via e-mail or post it on the Internet.
At this point, analog video is on its way out because it is an inferior medium in many ways to digital video. Analog camcorders have dropped in price to $300 to $500, while digital camcorders start at about $650, so it's certainly tempting to pick up an analog camcorder. If you're looking toward the future, though, a digital camcorder is a much better investment. As computer technology continues to improve, there will only be more possible uses for digital video, while analog video will fall more and more by the wayside.
Different analog camcorder formats all work the same way but they record on different types of tapes. The main differences between the tape formats are image resolution, sound quality, tape size, recording time and tape cost. For more information on each of the available formats, check out Camcorder Formats.
Most people have VHS VCRs, and the only kind of camcorders that record in a compatible tape are full size VHS and VHS-C units (you need a special cassette adapter to play VHS-C). But any camcorder is itself a functioning video player, and you can easily hook it up to your television or VHS VCR with standard RCA audio/video cables or coaxial cable. This will let you play movies on your television or make VHS copies that will play in standard VCRs.
Camcorder resolution is measured in horizontal lines of resolution, which tells you how much picture detail your video will have when you view it on a television. Televisions have vertical resolution and horizontal resolution. Vertical resolution is the number of horizontal scan lines that make up a picture. In any country, all conventional video signals will have the same vertical resolution because a television's scanning electron gun always paints the horizontal lines that make up television images in the same way. Essentially, horizontal resolution is a measure of how many vertical scan lines are included in a video signal. Another way to look at this is how many distinct bits of visual information is contained in each horizontal scan line. To get higher horizontal lines of resolution, a camcorder has to record more information for every horizontal scan line. A camcorder's lines of resolution measure simply tells you how much picture detail it records. For more on lines of resolution, check out this page.
These days, you can pick up a fairly good analog camcorder for $300. Digital camcorders have been rapidly falling in price over the past couple of years. Currently, the simpler models start at about $650 and the professional models cost $2,000 or more. As you get into more and more sophisticated equipment, camcorder prices just keep going up. Some top-of-the line models go for $100,000!
Any analog camcorder is already outdated. New computers have the capacity to do amazing things with video, but you have to get it into a digital form first. A digital camcorder records it this way and can also convert analog signals to a digital form. Most experts agree that the future of home video production is definitely digital. Additionally, digital camcorders offer better sound and a much higher resolution than analog models.
If you buy a digital camcorder, the first thing that will be outdated is the storage medium. Most of the models on the market today record on video tape, while more and more models in the future will record on DVDs and similar mediums. But today's camcorders should keep pace with accessory technology for many years in the future because as soon as you can download the information to a computer, it's stored as bytes on a hard disk, which will the dominant form of computer data storage for some time.
You need a FireWire (IEEE 1394) port on your computer and on your digital camcorder. This is now the interface standard for digital video. It sends information very quickly, both ways, so your camcorder can download video and your computer can control what your camcorder does. Many newer computers come with FireWire capabilities installed. You can buy a FireWire card if you don't already have this interface type. You'll also need a software application that can receive this video. This may be included on your computer, but if it isn't, some digital camcorders will come packaged with the necessary software. Check to see if the software is compatible with your operating system (Windows, Mac OS, etc.).
To take full advantage of digital video, you really need to have a fairly fast computer (a 500-MHz processor is a reasonable minimum) with a lot of memory and a lot of hard disk space. Digital video files are very big and difficult for a computer to handle and to run most editing programs, you need a lot of computer power. Even if your computer is not up to these standards, and you don't want to invest the money to upgrade it right now, you still might consider buying a digital camcorder. If you buy a new computer in a few years, there's a good chance it will have everything you need to edit digital video.
With digital video, it is possible to extract a single frame from your video footage and use it as a digital photo. Some camcorders also let you record a digital photograph directly to some sort of flash media, just as a still digital camera does (a few analog camcorder models have this function as well). Digital camcorders and digital still cameras both use CCDs to capture images and they both store this information in the same form -- bytes of data -- so they are very similar. The main difference is image resolution. Both digital still cameras and digital camcorders vary in image resolution, and there is some overlap in these ranges -- a high-end camcorder will actually produce a better picture than a low-end digital still camera. But the average digital still camera produces higher resolution images than the average digital camcorder.
Cool Facts
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The first camcorder patent was issued to the prolific American inventor Jerome Lemelson in 1980. Lemelson, who passed away in 1997, had tried to patent the idea for a camcorder in 1977, but the U.S. Patent Office rejected him, claiming the idea was too far-fetched and that no company could ever be able to manufacture and sell the device. Among other things, Lemelson also invented crucial components for the VCR, Walkman, automatic teller machine and barcode scanner.
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Instead of CCDs, the first camcorders used picture tubes, like the ones in bulky television video cameras
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The first home video cameras came in two pieces: a camera and a separate video recorder unit that users carried with a shoulder strap
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The first one-piece camcorder, Sony's Betamovie, came out in 1983. The unit did not have an electronic viewfinder or any playback capabilities.
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While most consumer camcorders cost less than $1,000, some professional units sell for $100,000 or more.
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High end camcorders use three CCD image sensors to capture full color, but most consumer camcorder models get by with only one CCD sensor.
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In August 2000, Hitachi released a DVD-RAM camcorder in Japan. The camcorder records digital video directly to a small DVD disk that holds 1.46 gigabytes on each side, for a total of two hours of footage (one hour at maximum resolution setting).
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Some digital still cameras, such as Sony's Ruvi unit, also have camcorder functions. The Ruvi looks like a digital still camera and has all the normal still camera functions, but it can also store 30 minutes of digital video on an internal cartridge.
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Some digital camcorders can shoot either for conventional televisions, which have a 4:3 aspect ratio, or high definition televisions (HDTV), which have a 16:9 aspect ratio.
Books
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Camcorder Video, by Joan Merrill. ISBN: 0131109251
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Camcorder Tricks and Special Effects, by Michael Stavros and Richard Lynch. ISBN: 093626982
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Video Camcorder School, by Malcom Squires. ISBN: 0895774593
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Digital Video for Dummies, by Martin Doucette. ISBN: 0764500236
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How to Use Digital Video, by Dave Johnson. ISBN: 0672319233
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Troubleshooting and Repairing Camcorders, by Homer L. Davidson. ISBN: 0070157596
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The Videomaker Handbook, by the editors of Videomaker Magazine. ISBN: 0240802268
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The Complete Idiot's Guide to Making Home Movies, by Steven Beal. ISBN: 0028636066
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Maintaining and Repairing VCRs and Camcorders, by Robert L. Goodman. ISBN: 0070248346 |
