Home Theater jargon, Meaning of home theater words
Here is a glossary of technical words used with home cinema. The home cinema technical words dictionary here is in alphabetical order with words starting with numbers showing first.
16:9 Projector Aspect Ratio
16:9 is the Aspect Ratio of a projector. Aspect Ratio means the ratio of the width of the screen against its height. So in 16:9 Projector the screen width and height will be at a ratio of 16:9. In short if the width of the screen is to be 8 feet wide, then the height of the screen can be calculated by dividing the width by 16 and multiplying by 9. In the case dividing 8 by 16 gives &farc12; and multiplying by 9 gives 4.5 feet as the height of the screen. It should be noted here that the size of a Projector screen is the diagonal size of the picture, from top left corner to bottom right corner or vice versa.
24p refers to the number of frames per second in a Movie Film. When movies are shot by Holywood Studios, they are filmed or recorded at the rate of 24 frames per second. The movies seen in Cinema Theaters are at 24 frames per second. When you see the same film on TV or DVD or Blu-ray the frame rate is 30 frames per second in USA transmission standards. So movies will have slightly faster movements when seen on a TV or Projector. So 24 frame movies are converted and recorded into videos at 30 frames per second by a method known as 3:2 pull down method described above. Purist videophiles prefer to see movies at the original 24 frames per second, Projector manufacturers have devised technology to convert back 30 frame movies back to the original 24 frame movie. This is a 2:3 pull down and Sony calls this 'True Cinema', LG calls it'Real Cinema' and Samsung calls it 'Cinema Smooth'
3D Projector gives a feeling that the Projector picture you are seeing is in real 3D, for example while watching a football game in 3D, you tend to duck to avoid the ball comming towards you. It is so realistic. See our website www.WhatTVs.Com for full explanation
4K Upscaling is the process by which any input from standard or HD sources can display on the new Ultra HD Projectors. 4K Upscaling is the process of converting Standard SD or HD content to Ultra HD content. For this Projector manufacturers are incorporating upconverter hardware known as 4K Upscaling on the new Ultra HD Projectors. Standard Definition or SD content is converted into HD content by interpolating extra pixels of picture data into the SD content to make it HD. But it is much more difficult to upconvert SD or HD content to Ultra HD content because of the extremely high pixel density of Ultra HD. Examples of some 4K Upscaling already introduced are Toshiba CEVO 4K processing engine and Sony X-Reality Pro 4K.
5.1 and 7.1 Surround Sound
5.1-channel Surround Sound encodes the audio as five primary (full-range) channels plus a special LFE (low-frequency effects) channel for the subwoofer. The 5 channels of sound come from 5 speakers the centre speaker, 2 front speakers and 2 rear speakers and the .1 in the 5.1 is the sub-woofer. Similarly for 7.1 channel Surround Sound there are seven speakers and one sub woofer.
Aliasing is the rough edges on the outer surface of images or text on any screen, for example laptop screens. Anti-aliasing means correction of the Aliasing fault, mostly done with specialized software.
Ambient Light is the light surrounding the equipment in question, for example the surrounding light arounda projector screen.
An Anamorphic lens is a lens that is used to convert one format picture into another format, for example to convert 4:3 aspect ratio movies into 16:9 widescreen format.
ANSI is the short form or abbreviation for ‘American National Standards Institute’. When it you say to ANSI Lumens, it means the Lumens measured as per the American National Standards Institute.
Aspect Ratio of Projector Screen
This is the ratio between the width and height of the screen. In the figure on the right 'a' is the height and 'b' the width. The Aspect Ratio thus is b:a. HD Projector has an aspect ratio of 16:9. The Projector screen size is the diagonal measurement of the screen - 'd' in the figure here. Once you know the Aspect ratio and the diagonal measurement or the Projector size, you can calculate the width and height of the Projector screen by using the Pythagoras Theorem as shown in the picture. When widescreen video images are squeezed to fit a narrower aspect ratio. For example in countries where they do not have transmission of Television signals in the 16;9 aspect ratio, they compress 16:9 pictures into 4:3 aspect and transmit it. People and objects looks thinner if viewed in the 4:3 view, but when expanded into 16:9 ratio they look normal.
Blu-ray Disc (BD) is the new format recordings for video which replaces the DVD. The BD discs are the same size as DVDs and CDs but Blu-ray Discs can hold 25 GB per layer (dual layer discs 50 GB) compared with 4.7 GB per layer of the DVD. Blu-Ray HD 1080p or Blue Ray in true High Definition 1080p is available now.
Brightness of Projector is measured in Lumens in accordance with the American National Standards Institute.
Contrast Ratio is the ratio between whitest white and the blackest black in a standard picture produced by a projector. The larger the contrast ratio the better the projector is.
Component video consists of three signals. The first is luminance, indicating brightness or black & white information, known as the "Y" component. The second and third signals are the "color difference" signals to show how much blue and red there is relative to luminance. The blue component is "B-Y" and the red component is "R-Y". There is no separate Green signal, since Green colour is inferred from a combination of Y, B-Y, R-Y.
Component Video signals are the best connection you can make for Video signal if you have no HDMI cable available. It is superior to the S-Video and Composite video cables. Component video can carry HD signals and so is preferred over S-Video and Composite cables.
In 1953 when color television was first transmitted in the USA they needed a compressed signal of all the component video information in one signal for broadcast. This resulted in the 'Composite Video Signal'. Composite Video Jacks and cable are coloured Yellow as in the picture on the left. The problem with Composite signals are that first it compresses the 3 components of the Video signal into one and broadcast it. The TV then has to uncompress all of it back into the three components. This leads to loss of quality and the final picture would have lost its sharpness and colors. Composite Video connection should only be made as the very last resort.
Digital audio Cables
To get the maximum benefit of digital sound, quality audio cables must be used. THe two audio connections widely used are the Optical Audio Cable called TOSLINK (short for 'Toshiba Link') and the Coaxial Audio Cable which have 75 ohm normal antenna Cable and an RCA connector at the ends. These cables are used to connect DVD players, CD playes, STB, etc. to Amplifiers or to the Projector direct to play multichannel surround sound like Dolby Digital and DTS. HDMI connections also support Digital Audio and newer Projectors have a feature called 'Audio Return Channel that sends back the Audio signal for Amplifiers to amplify and play Surround Sound.
Making digital images appear smoother by adding color or random noise during the digitization process.
DLP full form
The full form of DLP is 'Digital Light Processing', a projection technology developed by Texas Instruments using Digital Micromirror Device (DMD) microchip. The DMD chip consists of many tiny swiveling mirrors which reflect the image on to the screen. Each mirror in a DMD Chip represents one pixel in the digital image, so for example and HD DLP DMD chip will have 1920x1080 or a little more than 2 million mirrors assembled on a tiny DLP Chip. The DLP chip mirrors vibrates or wobbles to either reflect the light beam to the final image or rejects the light falling on it.
There are two types of DLP projectors, single-chip models and 3 chip models. In a single chip DLP projector, a high speed spinning wheel is used to make the required primary colors Red, Green and Blue to be reflected off the DMD. The spinning wheel colors cause an effect known as the 'Rainbow effect' on a small percentage of viewers. The 3 DMD chip projectors do not suffer from this effect and are used by most modern cinema theaters to project movies on their large screens.
Dolby Atmos meaning
Dolby Atmos is a new type of 3D surround sound system, which adds speakers overhead in addition to the normal front, center, side and back speakers. The overhead speakers add a third dimension to the surround sound to give true 3D surround sound.
With the new Dolby Atmos home sound systems sound comes from the top of your head as well, and this gives stunning sound to scenes like in a thunder storm, where you can feel the deafening sound of thunder overhead from the top speakers, and the natural sound of rain falling on the ground around you coming from the front, side and rear speakers.
Now it is now possible to enjoy the fantastic ATMOS Surround sound at home with new Dolby Atmos surround sound systems from famous Audio companies like Denon, Marantz, Onkyo, Pioneer and Yamaha. These Companies are introducing many new Dolby Atmos Audio Receivers either stand alone Dolby Atmos Receivers or as Dolby Atmos Home Theatre in a Box (HTIB) complete with receiver and all the required speakers.
This is the link to Amazon.com website to see Dolby Amos Home Theater Systems on offer
Dolby Digital is an audio compression technology developed by Dolby Laboratories. Till 1994 it used to be known as Dolby Stereo. Dolby Digital normally gives 5.1-channel surround sound. To quote from the Dolby site "Dolby® Digital is an industry-standard surround sound audio codec designed to deliver 5.1 channels of audio to many popular forms of entertainment including DVDs; Blu-ray Discs; cable, broadcast, and satellite Projector programming; PCs; and even video games. An advanced encoding/decoding technology, Dolby Digital reproduces multichannel audio to deliver a cinematic audio experience."
DTS full form
The full form of DTS is 'Digital Theater Systems'. DTS is a 5.1 and 7.1 multichannel audio surround sound technology developed by DTS Inc. (Digital Theater Systems Inc.)
Edge blending is the technology by which images from two or more projectors are seamlessly merged to produce a combination large image.
Energy Star is an international standard for energy efficient consumer products first introduced in the USA by the EPA (Environmental Protection Agency) in 1992. Similar programs are now being implemented in almost all countries of the world, with each country setting its own standards for energy efficiency of Appliances and electric equipments. An energy star rating logo / certificate stuck prominatly in front of Electrical devices is mandatory in many countries.
The Focal length of a lens is the distance between the lens and its focal point. A Wide Angle lens has a small focal length and a telephoto lens has a much bigger focal length.
Ghosting in an image on the projector screen means that there is a shadow like mirror image around all objects on the screen image. It could be due to several problems, but is usually a problem of the source material of the video.
HDMI full form
The full form of HDMI is 'High Definition Multimedia Interface' and is the best type of connection available so far for high quality TV and Projector inputs including HD and 4K UHD content. A picture of the 2 plugs at the end of an HDMI cable is shown in the picture here.
To quote from the HDMI.org website "HDMI technology is the global standard for connecting high-definition products: the uncompressed, all-digital interface that delivers both dazzling quality and unmatched ease of use. Over 1,000 manufacturers now incorporate HDMI connectivity into a growing list of consumer products: HDTV, Blu-ray Disc players, multimedia PCs, gaming systems, digital cameras and camcorders, mobile devices and more. It’s the one cable that transmits digital video, digital audio, and control data through a single high-speed link, making it the best and easiest way to turn your TV into a home entertainment powerhouse."
HDMI cables new standard is 1.4. Older HDMI cables standard of 1.3 works fine with most equipments but for 3D and 4K UHD content you must use an HDMI 1.4 cable. For a complete FAQ on HDMI cables see the HDMI FAQ and also see this Video explaining what HDMI cables and connections are.
The term 'HD Ready' was introduced by 'The European Industry Association for Information Systems' (EICTA). 'HD ready' means the Projector has the minimum screen resolution (at least 1280x720) and digital sockets (HDMI or DVI) to receive and display an HD picture. HD ready is not a High Definition Projector, but it can play HDProjector to give a picture quality that is near the quality of HDProjector. When you want to buy a full HD-Projector, make sure that the 'Native Resolution' of the Projector is 1920x1080.
HDTV stands for High Definition Television with 1920x1080 pixels and a 16:9 aspect ratio.
High Gain Screen
A High Gain Screen uses reflective material on the screen surface to reflect back most of the light falling on it towards the viewer to give a much brighter picture than normal screens.
Horizontal Resolution is the number of horizontal lines of resolution in a projected picture. For example HDTV has 1920 vertical lines of horizontal resolution and 1080 horizontal lines of vertical resolution.
Hybrid Projectors use two types of lamps for its light source, most often LED and Laser Light sources.
Hz Projector meaning
Hz is the symbol for 'Hertz' and is a measurement of frequency, the number of cycles per second. Hz in TV or Projector means the number of TV or Projector picture refresh cycles there is. It is better to have a higher Hz since fast action sports scenes will not be blurred, like a fast moving football will not look blurred. To explain Hz, instead of the normal 50 or 60 frames per second that is there in normal video, the TV or Projector with high Hz shows more frames per second. The extra frames are automatically added or interpolated inbetween normal picture frames to make the scene much smoother.
When projectors are ceiling mounted, they are mounted upside down, so the image has to be projected upside down and this feature in projectors is called ‘Invert image’.
Keystone: Horizontal and Vertical Keystone Correction
Keystone literally means the wedge shaped stone piece at the top of a masonry arch, but in projectors it refers to the wedge shaped pictures on the screen due to the projector and the screen not aligned properly. Projectors have a manual Keystone Correction feature to correct this out of shape picture on the screen. High-end projectors have fully automatic Keystone correction feature whereby the projector detects and corrects the keystoned image automatically with the touch of a button on the projectors remote control.
LCD' is the short form for 'Liquid Crystal Display' and is the same technology that you find inside an LED/LCD TV. The LCD panel is made up of millions of tiny Liquid Crystals, one each for every pixel in a Digital picture: that means for the High Definition HD format there will be 1920x1080 which equals to just over 2 million Liquid crystals in each tiny LCD Chip.
The tiny Liquid Crystals are sandwiched between two glass panels. This assembly is known as the LCD panel. When the liquid crystal elements in the LCD panel are charged with electricity, the crystals “untwist” to let a certain amount of light through the LCD panel. LCD by itself produces no light, it only either blocks or lets light through. Therefore in a TV it requires a backlight to show the picture on the TV screen and in a projector RGB light passes through 3 LCD panels and then recombined as white coloured light and projected on to the screen.
LED Projectors explained
LED projectors utilize LED bulbs in Red, Green and Blue RGB colors and so do not have to split white light into its individual colors. This saves a lot of space in the projector body and thus LED projectors can be made much smaller and lighter. Also the LED projector lamps have a Half Life of over 20,000 hours, some even claiming 60,000 hours. LED bulbs being solid state devices, makes LED projectors much sturdier than projectors with metal halide lamps.
LCOS stands for 'Liquid Crystal on Silicon' and is a type of digital image processing Chip that is able to produce Projector images that are superior to both LCD and DLP images. The problem is that LCoS Projectors are more expensive than either LCD or DLP projectors. The best LCoS Projectors are made by JVC and Sony. JVC produces LCoS projectors are branded 'D-ILA' which stands for 'Direct Drive Image Light Amplifier' and Sony LCoS brand 'SXRD' stands for 'Silicon X-tal Reflective Display'.
The Lens Shift in a projector is able to move the projected image up or down when it is called the ‘Vertical Shift’. The horizontal Shift in a projector is when the projected screen image is moved sideways to the left or right. Most projectors have manual controls on the projector to do the Lens shift function. In some high end projectors this function can be motorized and remotely controlled.
'Lumen' is a measure of the light output of the projector lamp and measures how much light the projector Lamp is capable of producing.
Metal Halide Lamp
Metal Halide lamps are the most common type of lamps or bulbs used in projectors. A metal halide lamp for projectors is also known as HID or High Intensity Discharge Lamp or UHP Lamps or Ultra-High-Pressure lamps. Metal Halide Lamps work with an electric arc inside a high pressure glass bulb containing a mixture of Mercury vapor and a metal halide vapor, usually Sodium Iodide. Metal Halide lamps are very efficient, producing high intensity white light of about 75 - 100 Lumens per watt. The main problem with Metal Halide projector lamps is the heat it produces, which requires special cooling fans which may make some noise and the very short life of the lamps of about 5000 hours of use.
Native resolution is the inbuilt resolution of the projector chip, like for example an HD ready projector will have a native resolution of only 1280x720 pixels, but is able to project full HD picture of 1920x1080 pixels
NTSC is an abbreviation for 'National Television System Committee' and is the standard used in USA Projector broadcasts. It uses a resolution of 525 lines and transmits 60 frames per second. The 60 frames per second is derived because the frequency of the electric power supply in USA is at 60Hz. In UK and some other countries where the electric power supply is at 50 Hz, uses the PAL system with a frame rate of 50 frames per second in sync with the electricity frequency. For Digital broadcasts in the USA a new standard, the ATSC has replaced the NTSC since June, 2009.
Optical Audio Cable
An Optical Audio Cable is an audio connection cable which uses an optical fiber to light to transmit digital audio signals. It is sometimes called TOSLINK (short for 'Toshiba Link').
PAL stands for ‘Phase Alternating Line’ and is an analogue color encoding system for TV broadcast used in UK and many of the countries which were under the British Empire of the past – the Commonwealth countries. It has 625-line frames and 50 frames per second.
A pixel is the short form of ‘Picture Element’ where the ‘Pix’ stands for 'picture element'. A Pixel is the smallest element which goes to make the picture on the TV or an LCD or DLP or LCoS Chip in a projector. Each color pixel is a combination of Red, Green and Blue subpixels. If you go close up to any television you can see the pixels arranged in a mosquito net like pattern. More the number of pixels in a picture the sharper it becomes. In HDTV there are 1920x1080 pixels totaling over 2 million or 2 MegaPixels.
Power Zoom of a projector lens means that the zoom function of the projector lens is motorized and the Zoom of the projector can be controlled by the remote control.
Projection Axis is an imaginary line from the center of the projection lens to the center of the screen.
Rainbow effect is a problem some people experience when they watch single chip DLP projectors. This is caused by the color wheel in single chip DLP projectors to produce RGB light. The Rainbow Effect in some people who have the illusion of seeing flashes of colours Red, Green and Blue like a rainbow, even after they stop watching the DLP picture. The cause of the Rainbow Effect is caused by the illusion created by the single chip DLP picture showing in sequence, a series of partial RGB color pictures. Faster color wheels with 6 segments of RGB color instead of 3 seems to reduce the Rainbow Effect in people.
In Rear projection the Projector projects the picture to the back or rear of a translucent screen and the audience is in front of the screen.
Refresh Rate of Projector
Refresh rate is how many times per second the image changes on the screen. Higher refresh rate helps in reducing the motion blur on fast moving scenes, like the football looks blurred on the Projector when it is moving fast. ‘Hz’ is a symbol for 'Hertz' and is a measurement of frequency, the number of cycles per second.
Resolution of a Projector or TV is expressed by the total number of pixels horizontally into the number of pixels vertically. This is called the Native Resolution of the Projector - for example the resolution of high definition Projector or HD Projector is 1920 horizontal and 1080 vertical pixels (1920x1080). HD Ready Projector has resolution of 1280x720 or 1,366x768. In Digital Camera talk, it would be 2.07 Mega Pixel for full HD Projector (1920x1080) and 0.92 Mega Pixel for HD ready Projector (1280x720).
RF Input or Jack
RF means the Radio Frequency. Input sockets using RF technology is called an analog connection. It is also referred to as the '75-ohm coaxial' connection. This is used for connecting external dish antennas to components having a built-in tuner, such as DTH (direct to home) STB (set top box) or satellite receivers, Projectors, etc. RF cable connectors are called "F-type" connectors, and either screw onto the 75-ohm jack or on older Projectors you see the push type jack. In this connection it should be mentioned that there are several qualities of coaxial cables used to connect the external antennas. Make sure you get a good quality cable, because the loss of signal quality suffers if inferior cables are used. For example use cables marked RG-6 instead of the standard RG-59 cables.
RGB stands for the primary colors Red, Green and Blue. The color in a digital picture, like the video signals transmitted by TV shows, is stored and processed using just 3 colors: Red, Green and Blue, usually written as RGB color. When these colors are combined or added together in different proportions, millions of colors can be produced on a Projector or TV screen
Screen Door Effect
Screen Door Effect is a phenomenon in LCD Projectors where a faint net like pattern appears on the screen of a projected LCD picture. This is actually the pattern of individual pixels and it feels as if looking through a net or the mesh of a screen door. This problem is only noticeable when you go close-up to the screen.
SECAM stands for the French 'Séquentiel couleur avec mémoire' which translates to 'Sequential Color with Memory' and is an analog TV color system used in France and the French colonies.
Soundbar, What is Soundbar
The aim of Flat screen Projector manufacturers is to make their Projectors as slim as possible. So they have no place in the Projector to have good speakers or to put sound amplifiers. So all flat screen Projectors suffer from poor sound quality or their sound is not clearly audible. The standard sound output of large flat screen Projectors are 10 Watts into 2 channels to give a total sound output of 20 Watts. For these huge Projectors this sound is not at all sufficient. An external HiFi multichannel sound amplifier with multichannel 5.1 or 7.1 speaker system is recommended to have full enjoyment of the widescreen Projector picture. Instead of the complicated amplifier and multi-speakers, a new sound system known as ‘Soundbars’ which projects sound in different directions to achieve 5.1 and 7.1 surround sound from a single speaker placed in front of the Projector is now available. The picture on the left shows how the sound beams from a soundbar placed just under the large screen picture is reflected of the wall to give 5.1 surround sound effect with just one sound bar. Each sound bar has many small directional speakers pointing in different directions to reflect the beams of sound from the appropriate walls. Yamaha's sound bar has an automatic system to point the beam in the correct direction for the room it is set up in.
Yamaha Japan revolutionized sound systems for flats screen Projectors with their invention of Soundbars and the best Projector Soundbars are still made by Yamaha Audio. Yamaha still makes the best Soundbar for Projector and, understandably, they are more expensive than competing brands.....For more on Sound bars visit our dedicated page on www.WhatTVs.Com
SPDIF: what is SPDIF connection
SPDIF stands for 'Sony Philips Digital Interface'. The SPDIF connection is also known as IEC 60958 connection. SPDIF can also be written as S/PDIF or S-PDIF. SPDIF is a Digital Audio connection found at the back of most home entertainment equipments like DVD, STB, etc. They are usually of two types - coaxial 75 ohm RCA plug connection and the 'Toslink', the optical digital connection. These are single wire connection from the output of DVDs or STBs to the Amplifier or Projector. They are high quality connections to transfer audio signals digitally over short distances for surround sound prograammes such as DTS, Dolby Digital and the newest Dolby ATMOS
This 4-pin one hole or socket connector which provides a good picture by transmitting the chrominance and luminance portions of a video signal separately. It is the next best connection to hook up video after the HDMI and Component video cables.
The Throw Distance of a projector is defined as the distance of the projector from the screen. The word ‘throw’ is used in the sense that the image is ‘thrown on the screen’. The throw distance is an important specification for a projector and specifies the minimum and maximum distance the projector can be mounted from the screen. Throw distance of a Projector can also be classified as Short Throw and Ultra-Short Throw Projectors that can be mounted very close to the screen.
Throw Ratio of a Projector is the Throw Distance divided by the maximum width of the screen at that distance. By knowing the Throw Ratio of projector, you can calculate how far back the projector has to be kept from the screen. For example if the width of the screen you want is 8 feet and the projector you plan to buy has a throw ratio of 1:1 to 1.5:1 with Zoom lens, then the projector has to be kept between 8x8=8ft and 8x1.5=12ft from the screen. If you know the distance you want to keep the projector in the room and the screen size you want, then you can calculate the throw ratio of the projector. For example you want to keep the projector 10 feet from the screen and you need a 8 feet screen width, then you need a projector with a throw ratio of 10/8=1.25.
TOSLINK: What is TOSLINK connection
TOSLINK is short for 'Toshiba Link', is a Digital Optical audio connection which is one of the best ways to connect surround sound signals of DVDs, HDProjector and Bluray audio signals to an older amplifier which does not have HDMI connections.
Zoom Lens of projector is able to vary the focal length of a projector and thereby able adjust the size of the image on a screen. This avoids having to move the projector closer or further to adjust the screen size.
Where to buy Home Theater Projectors and Projector Screens online
The best place to buy Projectors and Projector screens is the Amazon online store in your country. Amazon is best to buy online Projectors and Screens because not only are they very competitively priced, but you also have the assurance of service, and in the worst case, even return for a refund in case you are not satisfied.