understanding video tech Tom& jim Whole unit

Unit 21: Understanding Video Technology

Both PAL and SECAM are 25fps, NTSC on 25fps. 

PAL was developed by Walter Bruch, in Hannover, Germany. PAL was invented due to several errors with NTSC were highlighted, one of these was colour tone shifting. SECAM had started being developed in 1956, PAL Stands for PHase Alternating Line.The first version of SECAM was released in 1961and was the first european colour standard that started in france. It was named SECAM I but improvements had been made over time to improve image quality. This version was called SECAM II. Further improvements were madae on the system, hence it was named SECAM III A, Then SECAM III B. NTSC (The National Television System Committee) Was established in 1950 in the united states, it used 25fps,and has 525 scan lines, making it more detailed.NTSC was made in the united states and the NTSC was established by the Federal Communications Commission (FCC).NTSC video signals are still used in cctv today.

More recently cable (Virgin and BT), Satellite (Sky) and digital (Freeview) are used to broadcast television. Freeview is free to use and was launched in 20002, when the BBC and Crown Castle (Now Arqiva) officially took over the digital terrestrial television licences. Free-view was made in 2002 may 9th and to this day is one of the only free to air broadcast systems, this was made when BBC and crown court took over british terrestrial television.

Sky was founded in 1990, it is a british satellite broadcast. In the UK and Ireland Sky has over 10 million subscribers. 21st century fox have since owned 39.41% of the company.

Cable TV(Virgin and BT) was invented in the United states in the 1980's.There are two different standards for cable television, analogue, that would carry standard definition, and digital cable. This could carry High definition. 

Over the internet you can also access sites such as  4oD so view channels and series that you may have missed for free, but the downside to this is that they are not live and the shows are only online on the website for so long before they are deleted and removed.This is very similar to freeview, in freeview you can view movies and television series in advance of the official release sometimes, You have to pay every month for these services. 

Advantages/ Disadvantages:
Sky has more channels than cable TV and satellite but it is way more expensive as if you want to buy a large amount of channels you have to buy them monthly and are in bundles so you cant control exactly what you are paying for.

Viewing on the internet on sites like 4oD is free unlike if you was to buy something on sky but you can only watch a programme if it has been on tele recently whereas on sky these are repeated all of the time and if you get sky + you can record them

NTSC, PAL and SECAM are all television standards for analogue television. PAL is most used in the UK, Germany and Eastern Europe. SECAM is used in France, Russia and a few other countries. NTSC is used in the US, Canada and parts of South America.

These analogue system have now largely been replaced with digital terrestrial systems. Digital systems have advantages over analogue systems in that they have more capacity for data, lower operating costs and a better quality of picture. 

Digital

Advantages:

Better resolution 

Narrower bandwidth signal transmission

More compatible with modern technology such as computers, DVDs, Blu-Ray, and modern video processors in TVsMore precise, sharper, less blurry for higher resolutions

Disadvantages:Difficult to modulate, digital tuners more expensive than analogLimited color range Not backwards-compatible with older technology Easy to manipulateFlexibleCompatibility with other analogue systemsEasy internet connection 

More reliable

pixelating, and can freeze up (buffering)

Analogue 

Advantages:

Less expensive

Digital communications require greater bandwidth than analogue to transmit the same information.

Disadvantages:

Uses less bandwidth

Worse quality 

PAL

 In 1962 Walter Burch created PAL to keep up with the rapidly introduced colour television. PAL, short for Phase Alternating Line, is a colour encoding system for analogue television and is used in the UK today.  

Description	English: Oscilogram of PAL signal - 2 lines.
Date	1 December 2008 (original upload date)
Source	Transferred from en.wikipedia to Commons by Plrk using CommonsHelper.
Author	Markome at English Wikipedia

The name "Phase Alternating Line" describes the way that the phase of part of the colour information on the video signal is reversed with each line, which automatically corrects phase errors in the transmission of the signal by cancelling them out, at the expense of vertical frame colour resolution

(fps 25, 50 htz)

(Pal Signal)

Advantages and disadvantages of PAL

Advantages:

Adopted by most of Europe

Modification of NTSC to avoid colour distortion

Higher number of scan lines than NTSC

Higher gamma ratio than NTSC

Disadvantages:

Only runs at 25 frames per second (the lower the frame rate the worse for fast motion and more flicker)

Visibly colour saturation

Variable colour saturation

SECAM 

                                                                                       SECAM was developed in 1956 by soviet technicians. The first proposed system was called SECAM I in 1961, followed by other studies to improve compatibility and image quality. The first color television sets cost 5000 Francs. Colour TV was not very popular initially; only about 1500 people watched the inaugural program in colour. A year later, only 200,000 sets had been sold of an expected million. This pattern was similar to the earlier slow build-up of colour television popularity in the USA.

Short for Sequential Colour with Memory, SECAM is a colour TV standard that was introduced in the early 1960 in France. SECAM uses the same resolution as PAL(625 lines) but transmits the colour information slightly differently. 

(Fps 30)

(Broadcast systems in different countries)

Advantages and disadvantages of SECAM

Advantages:

Uses an FM frequency  - therefore less errors

Lower cost than NTSC and PAL

Higher number of scan lines than NTSC and PAL

Disadvantages:

Not suitable for studio use

Half the colour information is lost on each line

NTSC

National Television System Committee or NTSC is the analogue television system used in most of Northern and Southern America. 

NTSC colour encoding is used with the system television signal, which consists of 29.97 frames per second . Each frame is composed of two fields, each consisting of 262.5 scan lines, for a total of 525 scan lines. 

Original NTSC colorimetry (1953)	CIE 1931 x	CIE 1931 y
primary red	0.67	0.33
primary green	0.21	0.71
primary blue	0.14	0.08
white point (CIE Standard illuminant C)	0.310	0.316

After nearly 70 years of use, the vast majority of over-the-air NTSC transmissions in the United States were turned off on June 12, 2009, and August 31, 2011, in Canada and most other NTSC markets

(fps 29, 60htz)

Advantages and disadvantages of NTSC

Advantages:

Runs at nearly 30 frames per second (good for fast motion as the higher the frame rate the better, smoother the action appears and reduces visible flicker)

Has simpler circuits than PAL and SECAM

Has a less obvious picture noise

Is less costly than PAL

Disadvantages:

Small signal bandwidth which increases likelihood of interference

More costly than SECAM

Lower number of scan lines which reduces the quality on a large picture

Broadcasting Systems

Types of Television / ways to watch

Cable 

                                                          

Cable television previously known as Community Antenna Television or CATV originated in Pennsylvania in 1948.

Virgin media and BT broadband TV are 2 examples of cable TV. Many cable companies have upgraded to digital cable in the last 5 years but Virgin and BT have not as they both maintain a very fast connection. Fibre-optic cable provides the fastest internet and TV connection on the market at the moment which is one of the one of the major advantages to having cable. It's by far the quickest. 

Digital 

Digital TV originated in 1938 in the UK when towns such as Bristol used wires to carry television signals to homes which could not receive signals over the air.

Digital television is the transmission  and video  multiplexed signal, in contrast to the totally analog and channel separated signals used by analogue. An example of this is a freeview box.  The advantages of most digital TV systems is that after the initial payment for the box it is free which is why its still the most popular TV in the UK at the moment. 

Satellite 

Satellite TV works by launching a satellite into orbit. This technique revolutionised popular entertainment and sparked an explosion in technological development.

Three years after the satellite was first introduced in 1965 it was used to show pictures of the moon  which were broadcast into people's homes.

Sky is an example of a satellite TV station. It works with the addition of a satellite dish which is attached to the edge of your house, a reviver near your tv then picks up the signal. the reviver then has a wire from it which then connects to your television allowing you to watch fast live tv. 

Advantages and disadvantages of SKY

Advantages:

Thousands of channels to choose from

A wide variety of box office channels

Disadvantages:

Monthly cost

Monthly costs can increase and extra cost for special programmes such as sporting events

Internet 

Before 2006 there was no catch up services which allowed viewers to watch programmes at their convenience but now this is part of modern life.

Nexflix, BBC iplayer and 4OD are examples of internet television. Internet TV is usually a catch up service offering showings of programs from the last week. This is what i think will soon take over in an internet dominated world its only a matter of time until everyone is watching globe TV through the internet on a television set. There are also services such as youtube and Vimeo which allow a viewer to browse  through millions of videos to find exactly what there looking for. 

  

Advantages and disadvantages of internet

Advantages:

Can watch at your own convenience and at times to suit you i,e, available on demand

Disadvantages:

WIFI is not 100% reliable and the connection can be lost

Neflix and similar services charge a monthly fee

Types of cables 

Component cable

• The all-in-one solution for high-definition and standard TVs
• High-definition gaming output of 720p or 1080i
• Progressive-scan DVD playback in 480p
• Dolby Digital 5.1 Surround Sound output
• Component (Y, Pr, Pb) high definition video output

Transmits analog audio and composite video signals between devices such as televisions, satellite or cable receivers, VCRs, game console systems, speakers and more and usually comes with a red white and yellow cable which if not is only an audio cable. 

Audio Jack 

Connect portable devices such as MP3 players to an amplifier/radio with a 3.5mm in port. Suitable for your In Car Sound system Fits all ipods, iphones Multimedia speakers, and Mp3 playes with a 3.5mm jack

S-Video 

SVHS (also known as S-Video) plug (4 pins) to plug (4 pins). 

Carries video only (no sound). Results in better quality than composite cables. Standard now on most TV s and other visual devices (DVD players, camcorders, projectors) and now on most computers (as TV-Out or Video-In). 

In many European Union countries, S-Video is less common because of the dominance of the very well known and widely uses SCART cable which soon took over and gained world dominance because of its ability to transmit Sound 

DVI cabledigital Visual Interface (DVI)

DVI stands for Digital Video Interface; this type of cable is also used like an HDMI cable for high-definition television, DVD players, and game consoles such as an Xbox 360. Now that HDMI cables have become more of the standard and one sod the worlds most popular cables  used for HD television, DVI's are mostly used for computer connections, though they are still used to connect televisions to other components.

VGA

VGA (Video Graphics Array) originally intended computers in the 1980s though, now it has come to mean any cable or port with a VGA connector. It has a 15 pin connection and fits with most computer monitors today. . In addition, you will find VGA ports on many newer televisions so you can connect your computer to your TVs which enables a person to connect there laptop or computer to the TV to make the most of  a bigger screen. 

Mini-VGA

• Mini DisplayPort 1.1a compliant receiver offering 5.4 Gbps bandwidth over 2 lines
• Integrated triple 10-bit, 162 MHz video DAC for analog VGA signal output
• Supports up to 1080p, 1920 x 1200 reduced blanking video resolution

Cables

Composite Cables:

These carry only one signal and this is in standard definition- (480i/ 576i) , This is a very low quality in comparison to HD. The main uses for these cables are for SECAM, PAL and NTSC. They don't carry audio as it only carries a coloured video because they can carry only one signal. These are usually connected to an RCA jack, that are normally yellow.These cables unlike S-Video and component video cables only carry 1 signal.

S- Video:This is an analogue cable that carries standard definition (480i and 576i). These wires separate the black and white colour signals therefore improving the image quality compared to the composite cable but has a lower resolution compared to component video. Each pin has it's own ground pin, this is why there are four pins, the fifth pin is just to hold the wire in place. These S-Video cables (Super-video) separate black and white colouring signals to get a better image quality.

Component video:The red, green and blue wires distribute the colours 3 different ways corresponding to the wires colours.The original imput signal is split up into several component signals. This wire allows use for full HD resolution, but not all tv outputs support this, so it may be limited to1080i.
VGA:These wires are typically used for computer monitors, video cards, HDTVs, Laptops, net-books and a load more pieces of equipment. These use the same red, green and blue method as the Component wires do. These allow for higher resolutions, from 640x400 to 2048x1536. Higher resolution cables like this often require coaxial wiring.

DVI Cable:A DVI Cable is a digital cable meaning no loss in quality, These are found on HDTVs and video cards. There are three different types of these wires, DVI-D, DVI-A and DVI-I. These cables can reach resolutions up to 3840x2400. These do not transfer audio and these wires come in signal and dual links. These were made by Digital Display Working Group (DDWG) and are used a lot in computers to transfer the image from the monitor to the computer tower. These cables were specifically used to set a standard for the transfer of digital content due to the fact they had no loss in quality.

HDMI Cables:HDMI Cables are used in may different devices, ranging from computers, cameras, monitors, games consoles and Blu-ray players. HDMI is a single cable that carries video and audio signals digitally, and since its digital there is no loss in the quality. There are several different versions of these wires Version 1.0, that allows 1920x1080p, Version 1.4, that supports Ethernet, 3d and also 3840x2160p at 60fps. Finally version 2.0 supports 3840x2160p at 60fps.Jacks:These are used mainly depending on legnth to connect electric guitars- 1/4 inch jacks or commonly used for headphone wires-3.5mm, for phones and also speakers that are meant for a mobile device. These depending on what jack it is have two, three or four contacts, these with all 3 are called TRS connecters,  the T standing for tip, R for ring and S for sleeve. Devices that are compatible with these cables include televisions and phones that both have slots for these wires due to popular usages of headphones. In the media industry these are also used when editing and transferring foley sound, that is a large part of a films soundtrack.

XLR Connector:These are commonly used for microphones and are used a lot on stage for speakers and amplifiers, They use 3 pins, and is similar to the connection of a jack.There are two sides to these wires, female and male. The female side is usually source and the male side is input, and due to the shape and size of the design, it will never disconnect on it's own accord. In film a common use for these cables are the use of recording sound through a shotgun mic that would be plugged into the camera through this cable. These are similar to smaller and older DIN connecter, but are not 

The Mini DVI to VGA display adapter for connecting Macs or some PCs such a s ones made by sony equipped with a DVI port to an external VGA monitor or projector at home.

Camera Angles

low angle:

These increase height (useful for short actors like Tom Cruise or James McAvoy) and give a sense of speeded motion. Low angles help give a sense of confusion to a viewer, of powerlessness within the action of a scene. The background of a low angle shot will tend to be just sky or ceiling, the lack of detail about the setting adding to the disorientation of the viewer. The added height of the object may make it inspire fear and insecurity in the viewer, who is psychologically dominated by the figure on the screen.These can also be used similar to the worms eye view but not quite as exaggerated. and are often used in lord of the rings movies to make the characters around the character that the shot has been focused on seem more in power and depending on the situation more epic. These can also be used to show something above the character that he/she is not yet aware of yet.

 High angle:

Not so extreme as a bird's eye view. The camera is elevated above the action using a crane to give a general overview. High angles make the object photographed seem smaller, and less significant (or scary). The object or character often gets swallowed up by their setting - they become part of a wider picture.This is used in the pilot episode of the walking dead when Rick climbs into the tank and the camera pans upwards, showing for the first time in the series how extreme the situation has become. These shots often uncover something that isn't already known by the viewer, and can also be used as a POV shot from something much bigger than the subject of the shot to begin with. 

reverse POV:A point of view shot (also known as POV shot or a subjective camera) is a short film scene that shows what a character (the subject) is looking at (represented through the camera). It is usually established by being positioned between a shot of a character looking at something, and a shot showing the character's reaction (see  shot reverse shot ).The technique of POV is one of the foundations of film editing. Pov  Both of these shots are POV shots that help show someones perspective, sometimes making scenes more tense as unlike other shots you can't see any of their surroundings. These are often used to show that someone is being watched or spied on. Sometimes a POV shot is done over the shoulder who remains visible on the screen, when a shot is taken over the shoulder a pull focus is used to make a certain subject seem more dramatic.

Eye Level:

 A fairly neutral shot; the camera is positioned as though it is a human actually observing a scene, so that eg actors' heads are on a level with the focus. The camera will be placed approximately five to six feet from the ground. These re often used in films and television to show characters are having second thoughts or have another motive that hasn't been explained before in the production as the eyes can hint at this by moving them around, instead of being fixed on a singular spot. These shots can also cover as much emotion as a close up shot can as the eyes can easily show how someone is feeling without showing the background or anything around them, making the viewers more tense and unsure as well. 

Birds eye view shot : This shows a scene from directly overhead, a very unnatural and strange angle. Familiar objects viewed from this angle might seem totally unrecognisable at first (umbrellas in a crowd, dancers' legs). This shot does, however, put the audience in a godlike position, looking down on the action. People can be made to look insignificant, ant-like, part of a wider scheme of things. Hitchcock (and his admirers, like Brian de Palma) is fond of this style of shot.  

Off Centre:   

The Dutch angle, also known as Dutch tilt, canted angle, oblique angle or German angle, is a type of camera shot where the camera is tilted off to one side so that the shot is composed with vertical lines at an angle to the side of the frame. In cinematography, the Dutch angle is one of many cinematic techniques often used to portray psychological uneasiness or tension in the subject being filmed. Many Dutch angles are static shots, but in a moving Dutch angle shot the camera can pivot, pan or track along the established diagonal axis for the shot. A Dutch angle differs from a high-angle shot and low-angle shot in that those refer to placement of the camera in height relative to the subject, which for human subjects is mostly defined by a person's eye-line. A special type of Dutch angle is the Bavarian angle, where the angle is changed by 90° from the common angle where horizontal lines become vertical.

  Worms eye view:  

In cinematography a worm's-eye view is also useful in movie making. It is useful because it can be used as one of the camera shots/views. It is used in filming to look up to something to make an object look tall, and also makes them seem more in power as is often used in fantasy films, where a villain would be stood above another character, an example of this would be in the walking dead (spoiler) when dale has been shot by Daryl it shows dales POV just before he has been shot to make him look like he is in power and that Dale is a lot weaker than him.  

Upside down:    

This angle is used to give the viewer a disorientated feeling towards the scene also the point of view shot is used to make the viewer feel like they are there with the characters. These can also be used to show another characters point of view like the scene between batman and the joker in batman, that isn't just upside down but is also an off centre dutch angle shot to also make the joker seem even more insane than he was already perceived. 

Centre:

 the centre angle is a fairly neutral angle to give the viewer a balanced shot and you can add on extra effects such as zoom effects ect. But they are mainly used in conversation shots as they are more static. disadvantages of using these are that the scenes that use these are normally quite predictable and can be quite boring, but when filming slow scenes with a lot of dialogue this camera angle is one of the only ones you could do without confusing the viewers.          

Side ways Shot:

The shot is another used to disorientate the audience makes the scene more chaotic and distressed and in peril e.g. in gravity the use of side angle and upside down angle adds to the free flowing effect to the shot. These are quite hard to do especially without swapping to another shot, like what is done in Gravity as you would have to move the camera around the whole scene without getting any film crew members in the shot or any equipment in shot, these would often be done in single camera productions. Advantages of this shot on the other hand are that it adds an uncertainty in the scene making the viewer unaware as to what will happen, therefore making it more tense and uncomfortable for the viewer. 

Colour Temperature

When using cameras colour temperature is very important when filming and taking pictures as if you want to create a certain feel or filter for an image you have to control it. An example of controlling colour temperature would be in most rom com films, as they all use filters on lights surrounding the scene to make the scene look warmer.

Colour temperature is measured in Kelvin (K). When the colour temperature is over 5000k it is called a cool colour, whereas when the colour temperature is at 2700-3000k the colours are warm colours. 4000k is moonlight, 6500k is daylight and 15000k is clear blue sky. 

Tungsten lights are 3800k, that is very similar to the colour temperature of moonlight, that is 4100k. When filming in the sun the light will change depending on what time of day it is, as it can be red, orange, yellow or white. You can set the white balancing automatically with most cameras as they zoom in on a certain white object to determine the lighting and colours of the rest of the image.

 On some more expensive cameras you can set it manually to your own settings, on these you can white balance on things that aren't white, like light blue for example to make the rest of the image seem warmer, doing this means you won't have to use lighting gel and filters. If you were to use a gel it would not last very long as they wear off and also could even melt after a while depending on the heat from the light.

Filters are used on lamps to change the look of what is on the camera and change the colour temperature coming from the lamp. 

If you wanted to create a warm scene for example you can use a tungsten light to light up the scene and then use a blue gel filter to filter through the light and then white balance the blue through the camera to make the scene look brighter , you can then remove the filter as the camera has been light balanced. But if you wanted to create a more cold darker feel for a shot you would need to use a dark blue gel filter to get the correct white balance.

White Balance

White balance is the process of removing unrealistic color casts, so that objects which appear white in person are rendered white in your  photo. White balance has to take into account the "color temperature" of a light source, which refers to the relative warmth or coolness of white light. Our eyes are very good at judging what is white under different light sources, but digital cameras often have great difficulty with auto white balance and can create unsightly blue, orange, or even green color casts. Understanding digital white balance can help you avoid these color casts, thereby improving your photos under a wider range of lighting condition

Color temperature 

Color temperature refers to a characterization of the spectral properties of a light source and is commonly used during the production phase in the film and photography industries. Low color temperature is the warmer, more yellow to red light while high color temperature is the colder, more blue light. Daylight, for example, has a lower color temperature near dawn and a higher one during the day. The standard unit of measurement for color temperature is Kelvin (K). Some typical color values include the following;

• candles or oil lamps: 1000K
• household light bulbs: 2500K
• bright sunshine on a clear day: 6000K
• very overcast sky: 10,000K

Reference : http://www.studiadualne.info/whatis/TERM/C/color_temperature.html

Post production work though  guide  

Colour temperature is used within the film industry in order to create and allow for a better colour for the picture for example allow for more reds if you want to achieve a warm effect and blue is you want to achieve a cold or cooler tone eg a horror film . 

When creating or editing something on apple software you have to first create a new project folder, to do this you must hold ctrl (control) and then click to bring up a drop down option, then click new folder and in this you can save all of your files. Putting all of the footage in one folder makes it easier to find as it's all in one place and you can just search the folder name and find it, whereas if everything wasn't in a folder you would have to find them all individually.To start editing some footage you must first import some footage:

After the footage has finished importing you can then drag all of the footage from the project tab, thats in the top left and onto the time line, that's on the bottom. This is where you can just import all of the footage and only use what you want as you don't have to drag it all onto the timeline. On the timeline if you are trying to time footage then you can add a marker just by clicking on the top with the moue and align the clip with the time at the top, you can also zoom in on the timeline and see the frames for more optimal timing.The timeline:

Next to the timeline there are all of the tools that you would need to do a very basic edit of a clip, you can find transitions and effects on the effects and tools tabs at the top of the screen, but if you do use these you must render the clips that you have edited afterwards to add these effects. You can also add audio effects that will be under another option.Files:You can export clips as different file formats so you can use them on different software, like exporting something from paint to Photoshop for example. You can also compress files if you are planning on exporting them to put on something like YouTube s they take up less memory and are faster to upload.

Some files wont export onto other software though, as the newest final cut does not export over to older final cuts as the do have other features and some of them wouldn't update.

Post-Production

The first step in post production is choosing where the files have. usually the best idea is to create a folder to place your new project in, to do this right click and select new folder. (external or internally saved)   Save in this file all the work

All the files can be taken straight from DSLR,external recorder or the internet and placed in the folder. To import into final cut by using log and capture or import.

Scratch Disks 

Scratch disks are hard drives (or portions of space on a hard drive) that are used by Final Cut Pro for the temporary storage of files when editing videos. Although Final Cut Pro does not use the space for permanent storage of video files, scratch disks are vital when working with videos or clips that contain a lot of complex effects or transitions.

Setting scratch disks on Final Cut Pro is an

important part of the editing process

It dictates where the any footage captured (log and

transfer) will be stored, including rendered files,

waveform, cache and autosaves. 

Project and Sequence 

The timeline that you are working on currently has a sequence in of clips.  you can use more that one

sequence in single project. 

This is very useful when creating rushes eg.(quickly previewing footage for a director)  you can

create projects much more quickly when using this technique.  

   To create a new sequence in the current project

1.            Do one of the following
             Choose File > New > Sequence (or press Command-N).
   •      Control-click in the Viewer, then choose New Sequence from the shortcut menu.

Exporting Footage

   In some cases, you may want certain file formats for exported footage

   It may be because the client wants the video for mobile content, web use, DVD or even uncompressed allowing for high quality viewing 

   If you have a sequence in a low quality codec, and want a high quality export, then you can export in PNG format. This export will usually easily finish overnight even with a long project.

   ways to export, you can:

•         encode this movie to x264, H264, FLV or WMV (or any other format) 
•       drag it into DVD Studio Pro or iDVD to author an SD DVD
•        take it on a Firewire drive to a dub house to transfer to a broadcast format for cable/satellite, or for a film festival
•      or any other conceivable use.

Or the two main ways in the quicktime format 

QuickTime Movie (This is a high quality compressed version of your current sequence in

a .MOV file – an Apple developed format)

Quicktime Conversion (This allows you to choose from multiple file formats, the

resolution it exports and quality of the finished product)