Projection SCREENs
H O M E C I N E M A
An Introduction to Projection Screens
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 micro-perforations 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.
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 to 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 4K HDR Kaleidescape movie has higher resolution it can be projected larger. Whereas a DVD with lower resolution can be projected smaller if desired.
Take for example a 4:3 image from a 4K or 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.
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 4K HDR Kaleidescape movie has higher resolution it can be projected larger. Whereas a DVD with lower resolution can be projected smaller if desired.
Take for example a 4:3 image from a 4K or 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 (or above) 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 one 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. HOwever the drawback to that is that most of the screened image will look better than the spots which are perfed for the speakers.
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.
However if due to room/system constraints the only way to implement the system is to fire the speakers through the screen then one 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. HOwever the drawback to that is that most of the screened image will look better than the spots which are perfed for the speakers.
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.
Aspect Ratios
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 a variety of 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 movie server files are normally one of the following:
1.19Charlie Chaplin's City Lights (1931)Murnau's City Girl (1930)Fritz Lang's 'M' (1931)
1.33 – The NTSC ratio or 4:3 The Freshman
Fantasia
Seven Samurai
The Thief of Bagdad - (1.32 transfer)The General - (1.34 transfer)
1.37 – The Academy ratio 1932-1953 - actually 1.375The Adventures of Robin HoodCasablancaThe Red ShoesGone with the WindThe Wizard of OzThe African QueenCitizen KaneSingin' in the RainAn American In Paris
1.66 – 5:3 or 1.67Rear Window
A Passage to India
Dr. Strangelove
Some Like It Hot
Mary Poppins
(plus many foreign films)
1.78 – or 16:9 or 1.77 - the HDTV standardAvatar
Hugo
North by Northwest
The Ten Commandments
Sabrina (1954)
Days of Heaven
Dirty Dancing
Chris Botti in Boston (a wonderful concert video)
1.85 – 1953 to present - a common movie formatPleasantville
To Kill a Mockingbird
Much Ado About Nothing (1993)
Back to the Future
E.T.: The Extra-Terrestrial
The Princess Bride
Vertigo
Charade
The Greatest Game Ever Played
Sabrina (1995)
2.00Santana: Corazón - Live From MéxicoThe Last Emperor - (2.02 transfer) - (Criterion explains)Vera Cruz - (1.99 transfer)
2.20 – 70 mm standardThe Sound of Music
My Fair Lady
The Agony and the Ecstasy
Oklahoma!
Hello, Dolly!
Those Magnificent Men in Their Flying Machines
Chitty Chitty Bang Bang
Lawrence of Arabia - (2.19 transfer)
Patton - (2.19 transfer)
Baraka - (2.19 transfer)
West Side Story - (2.19 transfer)
South Pacific - (2.19 transfer)
Grand Prix - (2.21 transfer)Hamlet (Branagh) (1996) - (2.21 ransfer)Cleopatra - (2.22 transfer)2001: A Space Odyssey - (2.22 transfer)
2.35 – 1956-1972The Devil Wears Prada
Gandhi
Indiana Jones and the Raiders of the Lost Ark
Close Encounters of the Third Kind
Pride & Prejudice (2005)
Amélie
An Affair to Remember
King of Kings
Water for Elephants
2.40 – or often 2.39, but digital transfers from film can vary from 2.30-2.42Immortal Beloved
The Mask of Zorro
About Time
Amadeus
Skyfall
Samsara
2.55 – CinemaScope 1953-1957Sleeping Beauty
The Bridge on the River Kwai
Lola Montès
The Seven Year Itch
How to Marry a Millionaire
There's No Business Like Show Business
The Robe
East of Eden
Rebel Without a Cause
Love Is a Many-Splendored Thing
Lust for Life
Guys and Dolls
A Star is Born (1954)
The King and I (1956)
Hit the Deck (2.56 transfer)
Carmen Jones
Pete Kelly's Blues (2.57 transfer)
The Egyptian
The Man from Laramie
La La Land
2.76 – 1959-1966Ben-Hur
It's a Mad, Mad, Mad, Mad World
Mutiny on the Bounty (1962) - (2.77)Battle of the Bulge - (2.75)
2.89How the West Was Won
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. Whereas modern day films that are in the theaters now are typically 1.85 or 2.40. For home use many modern day films are also available in 1.78 (16:9). Plus there are many excellent music concert videos which are usually 16:9, although wonderful older concerts will be 4:3.
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 constant height screens and then masking is used to present some or all of the other aspect ratios. However in some instances a constant width screen can be more appropriate if there is sufficient ceiling height.
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.
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 minutiae required to design a high end home theater. That's what we are here for.
With regard to flatscreen aspect ratios, there have been a few flatscreens that have been 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 a video scaler 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 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
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 constant height screens and then masking is used to present some or all of the other aspect ratios. However in some instances a constant width screen can be more appropriate if there is sufficient ceiling height.
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.
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 minutiae required to design a high end home theater. That's what we are here for.
With regard to flatscreen aspect ratios, there have been a few flatscreens that have been 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 a video scaler 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 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
Viewing Distances
Viewing distances can vary depending on the resolution (4K or 1080p etc.), the quality of mastering of a given movie title, the projector quality, the size and quality of the screen material. There is much that can be said about this obviously...
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.
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.