Copyright Michael Karbo, Denmark, Europe.


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    Chapter 29. Video and film

    A camera is really constructed to take still photos (single pictures), but it can also record video films. The newer models are, in fact, really good at it Ė so good the films can very well be shown on a television screen! You can do this either directly from the camera, on a computer or by burning the film onto a so-called video C, which can be played on most DVD players.

    Live images

    Itís very easy to record video with a camera. You set the mode dial on video; one press on the release starts the recording. The cameraís lens catches the ďlive imagesĒ while the microphone catches the sound as well as it can.

    The video recording can continue as long as the camera has capacity for it. This can vary from 30 seconds up to many minutes.

    Video recording requires that you take many images every secondĖ otherwise they donít come alive. The more images you can take a second, the bigger the individual image (called frames) will be, and the better the filmís quality. 

    Computer power and RAM card

    There has to be a lot of computer power in a camera and a fast RAM card, if you want to take, for example, 30 frames a second (which is written as 30 fps). Not all cameras can handle this.

    Earlier digital cameras had a very limited video capacity. The format was 160 x 120 pixels with 15 images a second. This is a really bad quality, which canít really be used at all. On top of this the camera could only take a film, which was about 15 or 30 seconds long. Since then resolution has been increased four times as much in the QVGA format (320 X 240 pixels). This can almost be compared with the quality we know from normal (maybe a little worn) VHS-video cassette.

    The new generations of cameras record video films in VGA format, which corresponds to a normal TV quality. The resolution here is 640 X 480 pixels, and a lot of cameras can record these films with 30 images a second in a really good quality.

    The size of the RAM card limits the length of a film. But if you have a good, big RAM card of about 1 GB, then you can record nearly 15 minutes in the best quality, which is usually enough.

    Not for video freaks

    In many situations, you only need to record a few minutesí video film and modern digital cameras are very good for this!

    Figur 116. Video films can be recorded in different qualities. At the top you see a QVGA recording of 320 X 240 pixels.Below a VGA recording of 640 X 480 pixels.

    A video film can be played back on an ordinary TV. The VGA film here gives a really good image quality while the OVGA film is more like a rather bad VHS quality.

    The films can also be played back on a computer screen by using a player such as Windows Media Player or as here QuickTime Player. Real video enthusiasts, who love cutting and editing video films will probably not be at all satisfied with this type of image material. The images can be good but the sound is seldom ok. Ordinary users, who only sometimes record videos, can consider this as a sort of bonus that the camera can also take small attractive video films.

    Length of film (circa) on the RAM card with 30 images a second (fps) and quality:

    RAM card

    QVGA
    320 X 240

    VGA
    640 X 480

    64MB

    1,8 min

    55 sec.

    128MB

    3,7 min

    1,8 min

    256MB

    7,4 min

    3,7 min

    512MB

    14,8 min

    7,4 min.

    1 GB

    29,6 min

    14,8 min

    Figur 117. Examples of recording times for videos recorded with MJPEG coding. (e.g., Fujifilm S7000)

    As said before, the result can be really good. Many cameras have eminent objectives with good zoom and this can result in very fine video recordings.

    The camera ought to record in the highest resolution, however, with 30 images a second (640 X 480 pixels, 30 fps), so the technical quality is top quality. A good recording depends on the photographerís abilities. A tripod is indispensable if you want to be able to endure the film afterwards!

    Formats and coding

    The video film itself is coded in the camera. Itís not only images, but also sound, which is recorded in a film. Both sound and images are compressed in the camera.

    Video compression takes place with codecs. These are kinds of small programs, which can compress either sound or images in a certain way. Two codecs are necessary for producing a video; one of them packs the sound, the other packs the images, and both codecs are built into the camera.

    The images are hopefully packed with a codec like JPEG, as every single frame is packed as a little individual image. This coding is called MJPEG (Motion JPEG), but a lot of different sorts of codecs are to be found. The individual manufacturers use many of them and the area is in a rapid development.

    Figur 118. The properties of video films. Clip from QuickTime Player.     

    There are, for example, cameras that compress video images with a completely different sort of codecs, i.e. MPEG-4. This gives a much more powerful compression, so that there can be longer recordings on a RAM card.

    The sound doesnít take too much space as data, but it is packed with a codec anyway just like, for example, those that are used for MP3 music.

    Some cameras save film as AVI files, and others save them as MOV files; this isnít very important. The important thing is that you have a player than can handle video film and its codecs Ė regardless of whether the file is called AVI, MOV, MPG or something quite different.

    Playing back

    Video films can always be played back directly from a camera to a television. The cameraís own built-in codecs are used for decoding the film, which is then sent as analog video signals to the television.

    It gives you a good feeling when you see the family photos on a big television screen. Itís easy to set up so that you can, for example, also show your recordings, when you visit other places Ė as long as there is a television.

    Figur 119. The camera is connected to the televisionís video ports. Quick and easy and then both pictures and video films can be enjoyed from the sofa.

    Playback directly to a television can only be done as long as the film has been saved on the cameraís RAM card. Normally the film is transferred to a computer in the same way as with the photographs.

    Video film in a computer

    A camera is normally supplied with the software necessary for playing back video films in a computer. A sound card and loud speakers have to be connected for reproducing the sound.

    Software, which plays back video film in a computer, is called a player. The most widespread player is called Windows Media Player, and it comes with all versions of Windows.

    The problem with Windows Media Player is that it cannot always play films back as it has to use the same codecs, as the film has been coded with in the camera.

    You can experience that the sound can be played but there is no picture. The opposite can also happen: A fine picture but no sound, when a sound codec is missing. Both codecs have to be installed for the playback to work. Windows Media Player is arranged so that the program itself tries to fetch codecs from the Internet, if either the sound or the picture cannot be played back. But this doesnít always work. So if you send your video film to others, you canít be 100% sure that they can also play it back.

    Figur 120. Here a QuickTime Player is installed from a Canon CD ROM.

    There are other players, which can be fetched from the net free of charge. Here the program QuickTime Player is recommended; it can play back most formats and is supplied with a lot of cameras.

    Video ports

    Different TV standards are used in Europe and USA . So you have to set your camera to the standard PAL, if the film is to be shown directly on TV:

    Figur 121. When the video system is set on PAL, then the cameraís images and video film can be played back on a normal television anywhere in Europe.

    A video cable comes with a camera, which fits into a televisions socket. Most televisions have video ports either in the front or on the side. The yellow socket transfers the image and the white socket the sound. Both are connected to the television, where you find the same colour codes.

    The camera is set to show pictures (play back) or to play back video films. When the video cable is connected, signals are sent to the television instead of the LCD screen.

    A video port consists of a round socket (often yellow), which usually is to be found near the USB socket on the camera body. Video signals are analog. Sound and images are transferred in the same kinds of electric signals as a VHS tape recorder uses.

    Figur 122. A video film is coded (compressed) in the camera with the help of two codecs: one for sound and one for images.

    To be able to play back video films or process them, the same two codecs have to be used. This can give problems in connection with play back on a computer because the codecs are not installed in all programs. At the same time new and more effective codecs are constantly being developed and these also have to be installed in the computerís players.

    Figur 123. The cameraís video port is called A/V OUT here.

    From camera to CD and DVD

    Itís great that a camera can be directly connected to a television, where you can see your video film. The only problem is that the films take up a lot of room and have to, therefore, be transferred into a computer. RAM cards canít be used for the storage of video film!

    But you can easily burn video films onto a video CD. This is done with a certain computer program and only requires either a CD or a DVD burner in the computer.

    Video CD (VCD) and Super Video CD (SVCD) are formats, which are designed exactly for the films all DVD players support. This means that if you have produced a VCD, then it can be distributed in lots of copies because most people will be able to play it back on their television Ė as long as they have a normal DVD machine!

    Figur 124. The video cable. The two sockets, which are put into the television, can be seen at the top and at the bottom is the little round socket, which goes into the camera.

    Video discs function well; so donít be afraid to get going. Itís easy to burn the cameraís small videos into VCD or SVCD, and the quality is surprisingly good. There can usually be 20-40 minutes of film on a CD disc, so you can collect lots of small videos on one disc.

    Format

    Description

    VCD

    Used for film in 320 X 240 pixels. Compression with MPEG-1 and quality like the old VHS tapes.

    SVCD

    Used for film in 640 X 480 pixels. Compression with MPEG-2 and good TV quality.

    Figur 125. Two outstanding formats for the production of video discs, which can be played all over.

    Small menus can also be set up, which can be operated by the televisionís remote-controller and itís not just video film that can be burnt. You can also burn photographs, your own texts and sound recordings as well as video films. All of these things can be burnt together into the nicest productions on a CD or DVD.

    Software for producing video discs

    A lot of software exists for producing SVCD discs and VCD discs with sound, pictures and video clips. Some cameras are supplied with limited versions of programs like ImageMixer or Ulead VideoStudio. There is lots of user-friendly software, which makes it easy to produce video products.

    You start by importing the video films, photographs and sound files you want to include in the production. Then they are arranged in the order, they are to be entered. The best programs can make transitions between the individual video films so that one sequence can melt into the next.

    You can put single images in, which can be showed for a certain amount of seconds and you can record or write comments. All of it can be arranged with an excellent background and equipped with a menu structure, which makes it easy to navigate around in the production.

    If you just want to burn a couple of the cameraís video films on to a CD, this will take about half an hour. More ambitious productions can much longer to produce but the result will also be according to this.

    Interval recording

    Many cameras can make interval recordings. This is a function in the same family as video recording. You place your camera in a tripod and program it to, for example, take one image per second (or another interval period):

    Then you get a succession of images, which can, for example, show the movement of clouds in the sky or a flower, which is coming out. The function can also be used for taking small feature films, where you can move dolls or other small figures in between each recording. The camera has to be set on manual when you make interval recordings. This is important so that both the lighting and the white balance arenít altered from image to image. Finally, all the interval recordings can be collected together in a little film. You have to be a program like Antechinus Animator for this, which you can download from the web address www.c-point.com.

    Figur 126. With programs like ImageMixer VCD, you can design your own video productions very quickly.


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