Understanding video technology
Professional and amateur recording formats
Tape- Though video tape isn't very popular as a shooting format now, it was very popular in the '80's and '90's, with television programmes and even some movies being shot on it. These are the different tape formats: MicroMV, MiniDV, Video8, Hi8, Digital8, VHS-C, VHS, Betamax, 3/4' U-matic and Betacam. VHS editing equipment is expensive as a lot of equipment is needed, so it is more sensible to get it transferred to a digital format, which is a very cheap process.
Solid state- Filming Equipment with a solid state capability can record movies onto its own internal hard drive. Most digital cameras have this capability.
Disk- Some camcorders allow the user to record onto Minidiscs or MiniDVDs. These can be put into a computer and the files can be viewed.
Card- The most commonly used type of digital memory storage today is the SD card. These will store videos on them until the space is used up. The more high-end the camera, the higher class of memory card needs to be used, otherwise the camera will run slow.
Film- The first ever moving images were recorded on 35mm film. Over the years, this format has evolved, with several other formats being created. These formats are: 8mm, super 8mm, 9.5mm, 16mm, super 16mm, 35mm, super 35mm, 65mm and 70mm.
When light is exposed to film, the individual grains are clumped together to form the image. 35mm film actually has more exposure latitude than digital camera sensors, which is one of the reasons it is still commonly used to shoot movies, though it is a very expensive shooting option because it needs to be processed and telecined.
Professional and amateur recording formats
Tape- Though video tape isn't very popular as a shooting format now, it was very popular in the '80's and '90's, with television programmes and even some movies being shot on it. These are the different tape formats: MicroMV, MiniDV, Video8, Hi8, Digital8, VHS-C, VHS, Betamax, 3/4' U-matic and Betacam. VHS editing equipment is expensive as a lot of equipment is needed, so it is more sensible to get it transferred to a digital format, which is a very cheap process.
Solid state- Filming Equipment with a solid state capability can record movies onto its own internal hard drive. Most digital cameras have this capability.
Disk- Some camcorders allow the user to record onto Minidiscs or MiniDVDs. These can be put into a computer and the files can be viewed.
Card- The most commonly used type of digital memory storage today is the SD card. These will store videos on them until the space is used up. The more high-end the camera, the higher class of memory card needs to be used, otherwise the camera will run slow.
Film- The first ever moving images were recorded on 35mm film. Over the years, this format has evolved, with several other formats being created. These formats are: 8mm, super 8mm, 9.5mm, 16mm, super 16mm, 35mm, super 35mm, 65mm and 70mm.
When light is exposed to film, the individual grains are clumped together to form the image. 35mm film actually has more exposure latitude than digital camera sensors, which is one of the reasons it is still commonly used to shoot movies, though it is a very expensive shooting option because it needs to be processed and telecined.
Camera settings
Exposure- The exposure determines the amount of light let in through the lens of the camera to the image sensor. A subject that is correctly exposed will have detail visible in both the highlights and shadows. Overexposure will result in an image that is too bright with blown-out highlights and underexposure will result in an image that is too dark with no shadow detail. On video and film cameras, the exposure is determined by the aperture, frame rate and shutter angle. Only specialist cameras and cameras aimed at serious videographers and enable the user to adjust all these settings separately.
Aspect ratios-
16:9 (1.77:1)- This is the aspect ratio of widescreen Televisions. Anamorphic 16:9 is when an image of a different aspect ratio is squeezed into the 16:9 frame.
4:3 (1.33:1)- The is the aspect ratio of some television and video cameras.
4:3 (1.33:1)- The is the aspect ratio of some television and video cameras.
1.85:1- This is the American theatrical aspect ratio and is the "Academy flat" ratio.
1.66:1- This the European theatrical ratio and the aspect ratio of the 16mm film frame.
1.37:1- This has been the aspect ratio of the 35mm film frame since the invention of sound film and is the academy standard ratio.
2.35:1- This aspect ratio was recently replaced by 2.39:1 to hide film splices.
2.39:1- Originally 2.35:1, this aspect ratio is associated with a "cinematic", "epic" look.
2.39:1- Originally 2.35:1, this aspect ratio is associated with a "cinematic", "epic" look.
White balance- This is how white appears to the camera. It needs to be adjusted manually if you want white to be rendered white. The white balance can be deliberately set incorrectly to add a certain colour cast to an image.
Manual (AKA One push, white card and custom)- Only some cameras have manual White balance. This function allows the user to point the camera at a white surface and the camera sets the white balance according to that. It can also be used to deliberately put a certain colour cast on the image. Whatever colour you use, the resulting colour cast will be of the opposite colour. For example, pointing the camera at something orange would put a blue colour cast on the image.
The white balance on film cameras is determined by the choice of filter and whether tungsten balanced or daylight balanced film is used.
Focus- The focus is the area of the frame that is sharp. Other areas will be rendered soft, so focus is important when trying to obtain professional looking shots. Manual focus must be used if you want to ensure that subjects are in focus at all times, providing you can keep them in focus, because auto focus can choose to bring the wrong object into focus. The focus ring is used to control focus.
If a videographer wants to, they can choose to move to move the focus from one subject to another. This technique is called rack focusing and is used to draw the viewer's attention from one thing to another.
Below is an example of racking the focus between different objects.
Shutter angle- In stills photography, the length of exposure is controlled by the shutter speed. The length of exposure for each frame of film or video is controlled by the shutter angle. A smaller shutter angle will allow a lot of movement to happen in the shot without it blurring, though less light will be let in through to the image sensor. A larger shutter angle allows more light through, but results in blurred movement.
Below is a video showing the effects of the different shutter angles.
Gain- This brightens the image without adjusting the exposure. It is useful for low-light situations, but results in a noisy image and video artifacts.
Television standards
PAL (Phase alternating line)- PAL was created in Germany and first officially used in 1967. A PAL image is made up of 625 horizontal lines and 50 vertical lines. This television standard is aminly used in Europe and Australia.NTSC (National television system committee)- NTSC was created in the U.S.A and first officially used in 1954, making it the oldest television standard. An NTSC image is made up of 525 horizontal lines and 60 vertical lines. This television standard is mainly used in America.
SECAM (Sequential coleur avec memoire, or, Sequential colour with memory) - SECAM was created in France and first officially used in 1967. A SECAM image is made of 625 horizontal lines and 60 vertical lines. This television standard is mainly used in France.
Out of all these, PAL is the most common standard.
Video signals
DVI (Digital video interface)- DVI is a popular type of video signal that maximises the quality of flat panel LCD monitors and video graphics cards. DVI leads are most popular with computer users, whilst most television users use HDMI leads.
HDMI (High-Definition Multimedia Interface)- This type of signal supports 8 channel, 192kHz uncompressed audio and all compressed formats. There is no loss of quality when using this type of signal.
HD (High deifinition)- High definition is usually 1080p or 1080i. "P" stands for progressive and "i" stands for interlaced. In an interlaced frame, the odd line numbers are scanned first, then the even lines are scanned and then combined with the odd line scan. This can result in less blurred movement, but individual frames are badly affected.
In a progressive scan, the lines are scanned from top to bottom, meaning that this process is slower. This can make movement appear blurred, but individual frames look sharp.
Television broadcast systems
Terrestrial- This involves a television signal being sent from the broadcaster to the end user using only earthbound circuits.
Digital- This process involves television programmes being transmitted as digital signals which are decoded by the end user's television set. Since June 12th 2009, major television stations have been broadcasting digital signals.
Internet- The internet hosts lots of video websites, meaning that anything can be uploaded there. Anyone can become a "broadcaster", with the popularity of websites such as Youtube. BBC iplayer is a popular internet website, which features newly broadcast television shows.
Audio equipment
Radio mic- This type of mic usually clips onto a person's collar. The microphone is connected to a power pack, which is wirelessly connected to another power pack- this one plugs into the camera itself. The microphone is usually used when the camera is far away from the speaking subject or when no other available microphones record sound of a reasonable quality.
Cardioid mic- This type of microphone rejects sound from behind it and picks up sound only from in front of it.
Hypercardoid- Often referred to as a shotgun mic due to its shape, this exaggerates the effects of the cardoid mic and works well when there are a lot of unwanted sounds amongst the sound you want to record.
Omnidirectional- This type of mic picks up sound from all directions. It is useful for recording ambient sounds and speaking groups of people, though individual sounds are likely to be heard amongst other sounds.
Export formats
AVI (Audio video interleave)- Introduced by Microsoft in November 1992, an AVI file can have multiple streaming audio and video tracks. AVI files can be played back on most computers and some smart TVs and DVD players. It isn't suitable for streaming media on the internet.
H.264- Used by blu-ray players, this export format is ideal for high definition videos. It takes up a fair amount of computer space.
MPEG (Moving pictures expert group)- Established in 1988, the MPEG video format compresses video by storing the image changes made from frame to frame instead of storing each entire frame.
Transfer of footage to edit suite
Firewire- Firewire is a way of connecting equipment to a computer and transferring files. It was introduced in 1995 and is faster than a USB connection. The only downside of transferring files with this lead is that only certain cameras have a socket for this lead.
SD card- An SD card is a small card containing information. Most digital cameras use them to record data onto. They can be inserted into a computer and the files on them will appear on the computer. The files can be imported onto the computer from it. It may be easier and quicker to transfer data using the SD card, but there is the danger of data becoming corrupted because it is being inserted into and then taken out of equipment.
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