Bread Pitt
Member
The question often comes up when you want a large image: TV or video projector? The answer is not simple, it depends on what you want to prioritize. Some will prefer to have good blacks and strong contrasts, while others will bet everything on image size. In addition, we will also have to look at the context (amount of ambient light in the room) and the budget.
Black depth - Contrasts
The depth of blacks
It is the residual of the black, that is to say the deepest black that the image diffuser is capable of producing, which makes it possible to evaluate the depth of the blacks. The lower it is, the deeper the blacks in very dark scenes will be perceived.
In an obscure room, OLED TVs are unbeatable in this area. Indeed, they are capable of producing absolute blacks. But, apart from this technology, video projection is quite capable of competing with the world of television concerning the residual of black, especially vis-à-vis LCD IPS panels which is its weak point. It is even possible to obtain deeper blacks in video projection, by the choice of the projector, like a JVC for example, and / or by that of a gray canvas .
But beware, the depth of the blacks depends greatly on the ambient light in the room, and this is even more true in video projection than for a TV.
Sequential contrast
It is obtained by successively displaying a completely black test pattern (we say 0 IRE), then another all white pattern (we say 100 IRE). The sequential contrast is then the ratio between the luminance at 100 IRE and the luminance at 0 IRE:
Sequential contrast = luminance at 100 IRE / luminance at 0 IRE
For example, if the sequential contrast is 10,000: 1, it means that whites are 10,000 times brighter than blacks.
Knowledge of sequential contrast is mainly used to assess the ability of an image diffuser to produce good blacks in dark scenes. The higher it is, the more likely we are to have abyssal blacks.
In the television sector, we must distinguish OLED screens , whose sequential contrast is infinite, and LCD screens much less to their advantage in this area. For my part, I believe that an LCD TV must have at least a sequential contrast of 3000: 1 to start to perform in dark scenes. It should be noted that all high-end LCD TVs have a contrast enhancement device, so it is rare that this value is not greatly exceeded.
In the field of video projection, it is generally mono-DLP projectors which have the lowest sequential contrast, with values which rarely exceed 2000: 1 . Conversely, machines using LCD matrices , SXRD at Sony or D-ILA at JVC, have a much higher native sequential contrast, with values that can exceed 10,000: 1 , or even 20,000: 1 . For my part, I consider that the sequential contrast of a video projector starts to be good from 3000: 1 .
In terms of sequential contrast, there is no winner between the world of television and that of video projection because it greatly depends on the technology used.
ANSI contrast
It corresponds to the intra-image contrast at 50% white , that is to say that it is determined with a checkerboard pattern (see figure below) comprising as many white boxes as black.
Checkered pattern used to determine the ANSI contrast
To determine the ANSI contrast of an image broadcaster (TV or video projector), the operator will go into complete darkness and begin by measuring the luminance of the white boxes, then he calculates the average value. Then it performs the same operation with the black boxes. And finally, it calculates this contrast by applying the following formula:
ANSI contrast = average luminance of white boxes / average luminance of black boxes
For example, for a video projector, an ANSI contrast of 300: 1 means that the white boxes are 300 times brighter than the black ones. The higher the number, the brighter the image, the more contrast it will appear.
In video projection, a good ANSI contrast starts from 300: 1 and can go beyond 500: 1 for the best projectors in this area. For LCD televisions , it's much more, the best of them can exceed 5000: 1 ! As for OLED TVs , their ANSI contrast is considered to be infinite since the luminance of black is estimated in theory at 0 cd / m².
So, to simplify, we can admit that TVs have an ANSI contrast at least ten times stronger than that of a video projector , which gives them a very significant advantage. On this point, the video projection really can not fight, especially since the ANSI contrast of TVs is much better resistant to ambient light than that of video projectors.
Image size
The most common dimensions for televisions range from 32 ″ to 65 ″ (144 cm wide), while for projection screens the most popular sizes in Europe range from 2 meters wide (we speak of basic rather than width in video projection) up to 3 meters.
It is not so much on the width of the image or on its diagonal that we have to look, but much more on the surface. Indeed, what gives the feeling of immersion for a large image is its surface. The larger it is, the more the spectator has the feeling of being immersed in the scene. Conversely, if the surface of the image is small, the spectator has the sensation of looking at the world through a small "skylight".
The table below lists the dimensions of the largest TVs on the market and those of the most common projection screens.
Dimensions of TVs or projection screens in 16: 9 format
The feeling of immersion will start from a 2 m² image area. And it's a bare minimum! It is therefore illusory to believe that a 65 ″, or even 75 ″ TV, will offer the same immersion as in video projection. Only TVs with a minimum diagonal of 85 ″ can start to compete with this universe.
Let's compare for example a 65 ″ TV, which is already big in this area, and a projection screen of 2 meters basic, which can be considered rather small. Between these two screens, there is only 56 cm in width difference, but in terms of surface, we go almost from simple to double. That makes all the difference ! Thus, it is very difficult to have a feeling of immersion with a 65 ″ TV, unless you are positioned less than 2 meters back, which few people do, while for a projection screen of 2 meters, just stand within 3 meters and immersion is guaranteed.
In addition, a diagonal of 100 ″ constitutes a physical limit for TVs. Beyond this dimension, this poses manufacturing, storage and transport problems. The situation is very different in video projection where the size of the image is only limited by the light power of the projector or by the dimensions of the living rooms.
The battle for image size is therefore clearly won by the world of video projection , and when you exceed a base of 2.50 meters, you really have the feeling of being in the cinema.
Black depth - Contrasts
The depth of blacks
It is the residual of the black, that is to say the deepest black that the image diffuser is capable of producing, which makes it possible to evaluate the depth of the blacks. The lower it is, the deeper the blacks in very dark scenes will be perceived.
In an obscure room, OLED TVs are unbeatable in this area. Indeed, they are capable of producing absolute blacks. But, apart from this technology, video projection is quite capable of competing with the world of television concerning the residual of black, especially vis-à-vis LCD IPS panels which is its weak point. It is even possible to obtain deeper blacks in video projection, by the choice of the projector, like a JVC for example, and / or by that of a gray canvas .
But beware, the depth of the blacks depends greatly on the ambient light in the room, and this is even more true in video projection than for a TV.
Sequential contrast
It is obtained by successively displaying a completely black test pattern (we say 0 IRE), then another all white pattern (we say 100 IRE). The sequential contrast is then the ratio between the luminance at 100 IRE and the luminance at 0 IRE:
Sequential contrast = luminance at 100 IRE / luminance at 0 IRE
For example, if the sequential contrast is 10,000: 1, it means that whites are 10,000 times brighter than blacks.
Knowledge of sequential contrast is mainly used to assess the ability of an image diffuser to produce good blacks in dark scenes. The higher it is, the more likely we are to have abyssal blacks.
In the television sector, we must distinguish OLED screens , whose sequential contrast is infinite, and LCD screens much less to their advantage in this area. For my part, I believe that an LCD TV must have at least a sequential contrast of 3000: 1 to start to perform in dark scenes. It should be noted that all high-end LCD TVs have a contrast enhancement device, so it is rare that this value is not greatly exceeded.
In the field of video projection, it is generally mono-DLP projectors which have the lowest sequential contrast, with values which rarely exceed 2000: 1 . Conversely, machines using LCD matrices , SXRD at Sony or D-ILA at JVC, have a much higher native sequential contrast, with values that can exceed 10,000: 1 , or even 20,000: 1 . For my part, I consider that the sequential contrast of a video projector starts to be good from 3000: 1 .
In terms of sequential contrast, there is no winner between the world of television and that of video projection because it greatly depends on the technology used.
ANSI contrast
It corresponds to the intra-image contrast at 50% white , that is to say that it is determined with a checkerboard pattern (see figure below) comprising as many white boxes as black.
Checkered pattern used to determine the ANSI contrast
To determine the ANSI contrast of an image broadcaster (TV or video projector), the operator will go into complete darkness and begin by measuring the luminance of the white boxes, then he calculates the average value. Then it performs the same operation with the black boxes. And finally, it calculates this contrast by applying the following formula:
ANSI contrast = average luminance of white boxes / average luminance of black boxes
For example, for a video projector, an ANSI contrast of 300: 1 means that the white boxes are 300 times brighter than the black ones. The higher the number, the brighter the image, the more contrast it will appear.
In video projection, a good ANSI contrast starts from 300: 1 and can go beyond 500: 1 for the best projectors in this area. For LCD televisions , it's much more, the best of them can exceed 5000: 1 ! As for OLED TVs , their ANSI contrast is considered to be infinite since the luminance of black is estimated in theory at 0 cd / m².
So, to simplify, we can admit that TVs have an ANSI contrast at least ten times stronger than that of a video projector , which gives them a very significant advantage. On this point, the video projection really can not fight, especially since the ANSI contrast of TVs is much better resistant to ambient light than that of video projectors.
Image size
The most common dimensions for televisions range from 32 ″ to 65 ″ (144 cm wide), while for projection screens the most popular sizes in Europe range from 2 meters wide (we speak of basic rather than width in video projection) up to 3 meters.
It is not so much on the width of the image or on its diagonal that we have to look, but much more on the surface. Indeed, what gives the feeling of immersion for a large image is its surface. The larger it is, the more the spectator has the feeling of being immersed in the scene. Conversely, if the surface of the image is small, the spectator has the sensation of looking at the world through a small "skylight".
The table below lists the dimensions of the largest TVs on the market and those of the most common projection screens.
Dimensions of TVs or projection screens in 16: 9 format
The feeling of immersion will start from a 2 m² image area. And it's a bare minimum! It is therefore illusory to believe that a 65 ″, or even 75 ″ TV, will offer the same immersion as in video projection. Only TVs with a minimum diagonal of 85 ″ can start to compete with this universe.
Let's compare for example a 65 ″ TV, which is already big in this area, and a projection screen of 2 meters basic, which can be considered rather small. Between these two screens, there is only 56 cm in width difference, but in terms of surface, we go almost from simple to double. That makes all the difference ! Thus, it is very difficult to have a feeling of immersion with a 65 ″ TV, unless you are positioned less than 2 meters back, which few people do, while for a projection screen of 2 meters, just stand within 3 meters and immersion is guaranteed.
In addition, a diagonal of 100 ″ constitutes a physical limit for TVs. Beyond this dimension, this poses manufacturing, storage and transport problems. The situation is very different in video projection where the size of the image is only limited by the light power of the projector or by the dimensions of the living rooms.
The battle for image size is therefore clearly won by the world of video projection , and when you exceed a base of 2.50 meters, you really have the feeling of being in the cinema.
