Video Display Basics
Looking back over the past decade and seeing all that has transpired, one could conclude that the rate of evolution in video display technologies would have made Darwin's head spin! Today's variety of different video display technologies offers a spectrum of choices, each with a unique set of advantages. To choose the best technology for your system, consider your priorities:
Choosing the best product for your needs requires a familiarity with all the relevant technologies and all the latest product models. We recommend that you consult us early in your project. As a general guide, we've outlined some of the options below. Note that we are referring to higher performance equipment—as lower performance products have different profiles.
Note: There are products in each of the above categories that have either 1080P HD or 2160P 4K Ultra HD capability.
With regard to specific models of video components and displays because there are so many models from so many companies, coupled with the fact that the prices of video components change frequently, we do not attempt to list them all on our website. However as of 2015, for LCD flatscreens we usually recommend certain Sony models and for OLED we recommend certain LG models. Although models from Samsung or Sharp could also be considered as well. However we are not at this point recommending JVC, Hisense, Panasonic, and Vizio as these brands all suffer from the "soap opera effect" which is more technically termed as motion smoothing. The problem with JVC, Hisense, Panasonic, and Vizio flatscreens is that his motion smoothing cannot be turned off. Whereas the other brands mentioned have at least some models where motion smoothing can be defeated. Of course there are other considerations besides motion smoothing that are obviously important to consider when deciding upon a certain make and model flatscreen. For instance, there is the question of which resolution to choose: 1080p HD or 2160p Ultra HD. And what size to choose—as well as the native aspect ratio. Then there are technical parameters such as black level, color gamut, color accuracy, video dynamic range (after calibration of course), fully implemented HDMI 2.0/HDCP 2.2 support, etc.
High performance screens are available both for front and rear projection. Rear projection, while when done right can offer a superb picture, is more complicated and therefore is not as popular as front projection. But whether it is for front or rear projection, the choice of a screen will dramatically influence the performance of a projection system. You can select the screen material, size, aspect ratio, variable masking, and whether to incorporate microperforations or not. The screen may either be fixed to the front wall—or you can have a motorized screen which can be hidden in the ceiling and rolled down for viewing.
Video purists usually tend to choose constant-height screens. This means that as you switch aspect ratios from 4:3/1.33:1 (or even down to 1.19) to 2.40:1 (or even 2.55 or beyond) the screen height remains the same. Having said that the screen needs to be matched to the room, viewing distance, and the projector—and there are reasons why a constant-height screen is not always the best for certain applications. Screen masking is another subject about which a lot could be said, but to keep things simple the goal is to mask all of the aspect ratios that you would use. Adjustable masking is desirable because that way the aspect ratio of the projected image that you are watching is bordered on all 4 sides by movable black panels, thus framing the white screen area where the image is viewed within a non-reflective black border. For a comparison of a Constant Height vs. Constant Width screen click here.
The Ultimate in Projection Screens
For an ultra high end home theater a 4-way masking screen such as the Stewart Director's Choice can be the ultimate choice. One type of implementation is to have it work as a constant height screen for images from 16:9 and wider—and for images that are less wide than 16:9 the height can be increased such that a 4:3, 1.37, or 1.66 image will not be so small compared the square area of a 16:9 or a 2.40 aspect ratio image.
Take for example a 60" constant height screen. The 4:3 image will be 60" x 80" which is 4800 square inches. The 16:9 image will be about 60" x 107" which is about 6400 square inches. Whereas the 2.40 image will be 60" x 144" which is 8640 square inches. Compare that to a 70" x 144" 4-way masking screen, which is the same 144" width as the above. The 4:3 image will be approximately 70" x 93" which is 6533 square inches. Whereas the 2.40 image will be the same 60" x 144" which is 8640 square inches.
Or compare that to an 80" x 144" 4-way masking screen, which once again is the same 144" width as the screen example above. The 4:3 image can be 80" x 107" which is 8570 square inches. Whereas the 2.40 image will be the same 60" x 144" which is 8640 square inches.
Another advantage of this type of screen is that different resolutions can be projected at different image sizes. For instance because a 1080P Blu-ray has higher resolution it can be projected larger. Whereas a DVD with lower resolution can be projected smaller.
Take for example a 4:3 image from a 1080P Blu-ray which, for a certain viewing distance, might be most optimally projected as an 80" x 107" size image. Whereas for example a 4:3 image from a DVD, for a certain viewing distance, might be more optimally projected as an 60" x 80" size image.
For more information on the Stewart Filmscreen Director's Choice you are welcome to give us a call.
Note: This type of screen is optimally used with a high end projector that has a multitude of memory zoom and aspect ratio settings.
Perforated Screens vs. Non-Perforated Screens
The best possible audio and video fidelity is obtained if a non-perforated screen can be utilized. This approach usually necessitates that the center speaker be placed below the screen and that the left and right front speakers be on either side of the screen.
However if due to room/system constraints the only way to implement the system is to fire the speakers through the screen then the best approach would be to have selective "perfing", in which case the perfing is only in the region where the speakers are located behind the screen.
Another factor to take into consideration is whether the projector is a 1080P/2K or a 2160P 4K UHD one. At 4K the pixels are much smaller and the micro-perforations will interfere more with the image quality—whereas at 2k the micro-perforation interference will be less so.
In video the aspect ratio is the ratio of width to height and can either refer to the video display hardware itself or the image as seen on the screen and can be expressed in several ways. For decades the aspect ratio of the original NTSC format was called 4:3 which can also be expressed as 1.33:1 or just 1.33 for short. Now the HDTV format is referred to as 16:9 or 1.78. However there are many other aspect ratios than just those two. For instance over the years movies have been made in a variety of aspect ratios. And the aspect ratios of movies that have been transferred to either Blu-Ray or High Definition 1080p movie server files are normally one of the following:
Of the above the most commonly seen formats here in the US are 1.33, 1.37, 1.78, 1.85, 2.35, and 2.40. Though many older foreign films and some great US ones are in 1.66. And some of the greatest movies of all time were 70mm with a 2.20 aspect ration. Then there are the Cinemascope movies from the 1950's in 2.55.
Of course a high quality front (or rear) screen projection system that is properly designed and setup can present all of the above aspect ratios. At this point home theaters in which movies will be viewed are typically being setup with 2.40:1 aspect ratio screens and then masking is used to present some or all of the other aspect ratios.
If the system is going to use a projector and screen then ideally there should be an appropriate range match with regard to the aspect ratio of the lens and that of the screen. Examples of screen calculations & different high quality lens ranges follow:
Lens Aspect Ratios Example #1
There is of course more that could be said about aspect ratios, lenses, and screens! But once again you don't have to become an expert in all of the technical minutae required to design a high end home theater! That's what we are here for!
With regard to flatscreen aspect ratios, there are some flatscreens that are being marketed as 21:9 which are designed to show full frame 2.39 aspect ratio movies. Just like a projection system, this means then that there is a constant height for all aspect ratios 2.39 and smaller. Plus it allows video scalers to to use an easily implementable 4:3 scaling factor. However 21:9 (63:27) is an approximation of the actual ratio which is 64:27. You might be interested to know that 16:9 is the square of 4:3—and 64:27 is the cube of 4:3.
For a comparison of various screen sizes in terms of width, height, and square area—as well as comparing Constant Height screens vs. Constant Width Screens—click here.
For an 18 minute video on the history of aspect ratios in film with examples click here.
Then view this interesting video: On the Waterfront: A Tale of Three Aspect Ratios.
General Price Ranges of Video Projectors & Screens
Depending on your budget and what level of performance you wish to attain, there are quite a range of both HD 1080P and 4K UHD 2160P projectors as well as screens to choose from. Here are some rough ballparks of what you can expect in various general price ranges:
Note that the above price range estimates are for here in the US and are denominated in US dollars. Prices in other countries may be higher.
Video Projector Lamp Types
There are a variety of lamps used for video projection including various types of LED, metal halide, UHP, and xenon.
Many higher quality DLP video projectors use a high-pressure UHP lamp, which is also known as a mercury arc lamp. Better projectors will use a short-arc type of UHP lamp which produces a better quality of light—and for more light output two may be paired together. They are usually made with materials such as borosilicate glass and fused quartz, and because quartz is such a hard material to work with special machinery is necessary in order to heat and mold the quartz. You might be surprised to know that the glass in these lamps is not mass-produced but rather is usually hand-made by a glass-blower.
There are also some projectors that use LED as a light source. The advantage to using an LED design is the long-lasting nature of the light source as opposed to other light sources which occasionally need expensive bulb changes every few thousand hours. Whereas an LED light source can be give good quality light for something on the order of 30,000 hours. The challenge to using LED's as a light source has been getting sufficient brightness. However the latest designs have gotten better in this regard. Still as of 2015 it is best to limit screen widths to the 8-9' region.
Currently the best projectors utilize a Xenon lamp assembly along with the requisite power supply and associated circuitry. One advantage of Xenon lamps that most people aren't aware of is that it only takes about 10-15 minutes for them to warm up to their optimal light quality output. Whereas some UHP lamps can take 1-1.5 hours before they achieve their full optimal quality of light output. Xenon lamps can also put out a lot of light power which comes in handy for larger screens. In addition Xenon lamps inherently have a larger color gamut, also known as color space, which enables a larger range of color gradations to be seen thus enabling the most vivid, true-to-life color reproduction.
Other types of illumination are also appearing such as laser, etc. Time will tell if any of these newer types of illumination will have a place in a high quality residential cinema system.
Projector Light Output Relative to Ambient Light Levels
In a technically perfect viewing room everthing in the room—including walls, floor, and ceiling—would all be non-reflective black. Or alternatively everything would be a combination of photographic gray and black. Most people however don't have a totally dark room that is photographic gray or black. If a viewing room is not totally black even a dedicated home theater without windows, and with all the lights off, can still have the side walls and ceiling lit up from the light reflected off of the screen. The approach then is to make sure that there is sufficient light output from the projector for such viewing conditions such that the screen is lit up to the appropriate foot-lamberts target number. There are also certain types of screens that are available which are designed to operate in higher level ambient light conditions. In all cases we prefer to aim for a 10:1 or better ratio between the peak white measurement from the video display device projected on the screen relative to the level of ambient light.
With regard to viewing distances relative to screen size here are some guidelines for front projection:
There is more to the story than just that though. For instance take the case of a 1080p or 4K 3-chip DLP front projector with an anamorphic lens that is used for wide screen images of 2.40 or wider aspect ratios. Using a 2:40 aspect ratio unity gain screen which is 162" wide by 67.5" high, the minimum suggested front row viewing distance is about 2 times the screen height of 67.5" which when calculated would be a 135" suggested front row minimum viewing distance. However if an anamorphic lens is not being used and the projector can be used in the servo-zoom and focus mode then the minimum suggested front row viewing distance is about 1.5 times the screen height of 67.5" which would calculate to be about 101".
Note: the above viewing distance guidelines are for high end home theater projectors with top quality lenses coupled with high performance screens. And obviously source quality also needs to be taken into account as well.
Field of View
Field of View (FOV) is defined as the total angle between the viewing position and the left and right edges of the image projected on the screen. In other words this is the panorama of the viewing experience; the greater the FOV, the more immersive the experience. (For those that have experienced it think Cinerama here!) It is only more recently that the technology capable of reproducing this experience has been made available for residential viewing. Note that this logically applies to projector-based systems. The ideal of course is to achieve the optimal FOV, however that optimization is best done individually for a given system/room setup.
Note: The term "architectural cinema" is now being used to describe system/room combinations which are designed to a high level in every regard including FOV optimization.
At first glance it might not seem plausible, but all things being equal a 720p 3-chip projector can have noticeably more resolution than a 1080p single-chip DLP projector if the single chip DLP has a color wheel and the 3-chip DLP does not. The reason is that if the projector has a color wheel, that color wheel will reduce the perceived resolution of a video projector. Presently the highest quality projector image will come from a top quality 1080p or 2160p source on a high end 1080p or 2160p 4K UHD, either 1-chip or 3-chip, DLP projector with a top quality lens shown on a top quality screen with masking.
Given sufficient control over a variety of parameters, where possible we will design a home theater which utilizes a projected image to be accurate right down to the pixel level at all projected aspect ratios. To reach this level entails careful calculations and implementation. It would get rather techical to try to explain this in detail—but suffice it to say that it is the best way to go!
Ultimately if you have the opportunity to see a top quality 1080p Blu-ray disc, 1080p bit-for-bit Blu-ray quality file, or 2160p 4K UHD high quality file on the best projector/screen setup, one that has been properly engineered and professionally calibrated, it can be rather stunning to say the least! We know because we have a high end setup here on demo and even we are still amazed at the image quality every time we turn it on!
4K UHD 2160P
There are some 2160P 4K projectors (as well as flatscreens) that are now available—though 4K is now being termed 4K Ultra HD (or 4K UHD or 4K Ultra High Definition) for home theater use.
However there are some differences between 4K UHD specs which are aimed at home theater and 4K as it is designed for commercial theaters. Technically speaking the DCI Full Container 4K spec, which is used in commercial theaters, is 4096 pixels by 2160 pixels—and so it has the identical number of pixels vertically but is a number of pixels wider than 4K UHD which is 3840 x 2160.
Below is some more detail on DCI (Digital Cinema Initiative) 2k & 4K specifications:
Flat (1998 x 1080 or 3996 x 2160) ~1.85 aspect
4K Ultra HD 2160p has 3,840 x 2,160 pixels whereas HD 1080P has 1920 x 1080 pixels. Though as of early 2015 there is very little 4K UHD source material actually available for home use. However it has been officially announced that in late 2015 (or maybe 2016?) there will be high quality locally-stored 4K UHD files available as well as a standard for 4K UHD Blu-ray which will provide for native 4K UHD discs. However as of early 2015 there is a paucity of material available from Sony and Samsung which offer only a small number of titles of 2160p files.
Though there are some Blu-Ray players which will upconvert 1080P to 4K UHD—this is really only a stopgap measure. Until if and when sufficient high quality 4K UHD source material is available, we typically recommend sticking with 1080P for which there are a considerable array of Blu-Ray discs, as well as bit-for-bit Blu-Ray quality movie server files available, with more being released each week. However if you wish to be an early adopter then you should definitely talk to us so that we can give you the most up-to-date info and steer you in the right direction in terms of a home theater design that will do both 1080p HD as well as 2160p Ultra HD.
While it is a bit more cut and dried when it comes to flatscreens, there are several approaches if you are thinking of a projector/screen type of home theater. One thing that you may be interested in knowing is that there are some 1080P/2K high end projectors that are upgradeable to 2160P/4K. That way you can equip your home theater for 2K/1080p now and upgrade later if you wish. Or you might choose to go with a 4K projector now and use a video processor to up-rez any 1080p content.
Note: For for those with a Kaleidescape movie server bit-for-bit true Blu-ray quality downloads are available from the Kaleidescape Store. In 2015 Kaleidescape will release a 4K UHD player plus they we will have "attractive upgrade paths" available for those who already own their movie servers. And they have announced that they will have 2160P 4K UHD files available in the their download store! Here is a link for more info on 4K UHD.
DLP Chip Quality
There are different grades of chip quality as well as different sizes of those chips which are being utilized now in DLP projectors. The first thing to understand is that there are consumer grade DLP chips as well as exhibition grade DLP chips. Consumer grade chips range in size up to 0.95". And in the case of these DLP chips all things being equal a projector with a larger chip should be superior.
Exhibition grade DCI DLP chips range from 0.69" to 0.98" to 1.2" for high quality 1080p projectors. Whereas 4K projectors may use chips up to 1.4" in size. If you are seeking the highest quality picture then an exhibition grade DCI DLP chip coupled with a top grade lens is the ideal.
Projection Lens Quality
A high quality lens is required for a projector in order to produce a high quality picture. This can be especially important for projection as the larger the picture the more the lens quality is exposed for better or for worse. A quality lens for a projector can run $5000 or $10,000 or more. So for reasons of lens quality alone you simply can't expect a projector that costs a few thousand dollars inclusive of a cheap plastic lens to project a top quality image.
To put quality projection lens cost into perspective, the image that you view when watching movie is typically captured with a high quality lens. And you might be interested to know that a high quality lens used to film a movie can cost in the neighborhood of $50,000—although they can range even higher than that. For instance the world's most expensive lenses were used by Stanley Kubrick for one of his movies. These were special Zeiss super-fast 35mm & 50mm lenses with an F-stop of 0.7. These were used to shoot the candlelit scenes in "Barry Lyndon" (1975)—in other words the only light used for filming those scenes was from the candles themselves! The lenses have also been used to shoot scenes in several other films including "Schindler’s List”, “Shakespeare in Love”, and “The English Patient". These lenses were originally developed for a NASA project in order to take still photographs of the dark side of the moon. Only 10 were made—and Kubrick obtained of three of them. Today each of those camera lenses is probably worth—well if you have to ask you probably can't afford it...
Anamorphic vs. Non-Anamorphic
One advantage to using a projector with a motorized anamorphic lens is that movies much wider than the 2.40:1 aspect ratio can be fully masked with a constant height variable masking screen. Whereas with a non-anamorphic lens-type video projector typically only movies up to a 2.40 (or maybe a 2.55) aspect ratio will be fully masked with a constant height screen. While there are relatively few movies with aspect ratios wider than 2.40, those wider aspect movies may not be masked top and bottom with a constant height screen unless an anamorphic lens is utilized. For a non-anamorphic projector you may wish to use a screen that also has adjustable top and bottom masking. One reason why some people choose to forgo the anamorphic lens option is to save on the price of an anamorphic lens which can be range up to $15k or higher for a high quality motorized one.
Of course regardless of your projector and lens setup, ideally you will want to fully mask every movie aspect ratio. To do so the obvious choices are either a high quality 4-way fully adjustable masking screen, such as the Stewart Filmscreen Director's Choice which is the type of screen typically found in the home of a top Hollywood producer or director—or a constant-height masking screen.
If you are setting up a home theater with a video projector, one thing to keep in mind is the degree of reduction in light output when using a zoom lens—which is of course what most projectors utilize today. Depending upon where the projector is installed, the zoom lens will be in a different position from wide angle to telephoto. Understand that there are differing amounts of light output from the projector at different zoom positions—because zoom lenses as fitted to projectors aren't usually constant aperture. Therefore at the telephoto end a smaller aperture (bigger f-stop) equals more light. Of course the degree of loss of light will vary from projector lens to projector lens. For example, take a 1000 lumen projector which has a zoom lens with an f-stop of 1.7 to 2.1. Dividing 1.7 by 2.1 yields a factor of 0.6553. The light output of the projector is multiplied by that factor, thus giving a 655 lumens light output which is reducing brightness by up to a third in this example.
Another aspect to be taken into consideration is how many foot-lamberts a video projection system is capable of on a given screen size and material type when optimally adjusted. And by the way, the best measure of brightness isn't a claimed lumens specification of a projector but actual measured foot-lamberts at the screen after everything is set up and calibrated properly. In the days of film 12 foot-lamberts of brightness was normal. Today many digital theaters are targeting 14-22 foot-lamberts. For dedicated home theater rooms with good ambient light control however we find that most people prefer something in the 20-35 foot-lamberts region. For a high quality front projection system we typically like to have a system capable of 35-40 foot-lamberts, though we may adjust it down to something like 22-30 foot-lamberts depending upon client preferences.
However in the case of high levels of ambient light a projector setup in "daylight TV mode" may be asked to produce up to 80 foot-lamberts. It may also be good to have a bit more available headroom as a higher quality projector can automatically adjust the brightness over time to account for the projector bulb possibly getting dimmer with age so that the same level of brightness output is maintained.
Installation and Set-up and Video Calibration
Once all of the equipment is specified, and the room is ready to receive it, the various components need to be physically installed. Suffice it to say that we can provide the necessary expertise to install your video system so that everything is properly aligned. For instance the screen should be level and at the correct height relative to the projector lens. And the projector should have the correct throw distance for the particular model, type of lens, and screen size. Once everything is in place then we go through an initial setup and testing procedure.
After the setup is completed then the projector needs to be calibrated. Calibration ensures that your picture will look as good as possible. To talk about calibration in depth requires using a lot of technical jargon like gamma and black level which unless you are well-versed in video terminology will probably not be meaningful to you. However to briefly touch on the subject calibration can include such things as:
Calibration itself is a specialty and there are a handful of top recognized calibration experts here in the US. Given your system and location, we will utilize the most appropriate calibration technician for your installation.
Once your system is all set-up and calibrated then you can start viewing movies in all their glory! Occasionally you may also wish to use a demo disk to show what your new home cinema is capable of to your friends and family.
Of Course That Isn't All There There Is To It!
There are other aspects to consider as well when planning, installing, and tweaking a home theater installation. Suffice it to say that especially with projection systems, that they require carefully planning and implementation in order to fully realize the high performance levels that the equipment is actually capable of. Product specifications, configuration, installation, and calibration can get quite technical and involved. Of course, if you visit our showroom, we would be happy to talk to you about your home theater design and show you the stunning picture quality that we can achieve. You don't have to be an expert, that's what we are here for. In the end all you have to do is sit back and enjoy your wonderful home theater once it is installed!
To learn more about other aspects of home theater see Surround Audio Systems and Home Theater 3D screens for info about new developments in 3D screens. Also see D-Box for Home Theaters for info on motion-controlled seating effects which are synched to encoded movies titles.
NOTE: The current term for high end home theater is Architectural Cinema. But regardless of what you call it, if you are planning on coupling a high end projector/screen type of system with a high performance surround sound system you are invited to call and speak directly with Alan Goodwin at 781-893-9000 ext 14. He will be happy to discuss your project with you and provide you with the latest thinking with regard to the design and implementation of your project—whether it will be incorporated into an existing room or be in a new custom-designed for your home.
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