1080p refers to image resolution that represents 1,080 lines (or pixel rows) displayed sequentially on a TV screen. All lines or pixel rows are scanned or displayed progressively. This means that 1,920 pixels run across the screen and 1,080 pixels run from top to bottom with each line or pixel row displayed sequentially one after the other. To get the number of total pixels displayed on the entire screen area you multiply 1,920 x 1,080, which equals 2,073,600 or approximately 2.1 megapixels. TV technologies that support the making of TVs that can display 1080p resolution images include Plasma, LCD, OLED, and DLP. In order for a 1080p TV to display lower resolution video signals, such as analog, 480p, 720p, and 1080i it must upscale those incoming signals to 1080p. This means a 1080p display on a TV may be done with internal upscaling or by accepting a straight incoming 1080p signal.
1080p/60 vs 1080p/24
Almost all HDTVs that accept a 1080p input signal directly can accept what is known as 1080p/60. 1080p/60 represents a 1080p signal transferred and displayed at a rate of 60 frames-per-second (30 frames, with each frame, displayed twice per second). With the advent of Blu-ray Disc, a variation of 1080p was also implemented: 1080p/24. 1080p/24 represents the frame rate of standard 35mm film transferred directly in its default 24 frames-per-second from a source (such as a film on a Blu-ray disc). The idea is to give the image a more standard film look. This means that in order to display a 1080p/24 image on an HDTV it has to have the ability to accept an input of 1080p resolution at 24 frames per second. Almost all, but the earliest 1080p TV models can accept and display 24 frames per second signals. If you have a 1080p TV that doesn’t have this capability, all Blu-ray Disc players can also be set to output 720p, 1080i, or 1080p/60 signals and, in most cases, the Blu-ray Disc player will detect the appropriate resolution/frame rate that the TV can display automatically.
How 720p TVs Are Different Than 1080p TVs
Another thing that consumers need to be aware of are TVs that may accept a 1080p input signal but may have a built-in pixel resolution lower than 1920x1080, such as a 720p TV. If you buy a TV with either 1024x768 or 1366x768 default pixel resolution (which are promoted as 720p TVs), they can only display that number of pixels on the screen, running horizontally and vertically. As a result, a TV with a default 1024x768 or 1366x768 pixel resolution must downscale an incoming 1080p signal to display it on the screen as an image. Some older 720p TVs don’t accept 1080p input signals but will accept up to 1080i input signals. The number of incoming pixels is the same, but 1080i is an interlaced format (each row of pixels are sent alternately in an odd/even sequence), rather than a progressive format (each row of pixels is sent sequentially). To display these images a 720p TV has to scale the incoming signal and also “deinterlace” (combine) the lines or pixel rows of the interlaced image into a progressive image. If you purchase a TV with either 1024x768 or 1366x768 default pixel resolution, that is the resolution image you will see on the screen. Therefore, a 1920x1080p image will be downscaled to 720p or a 480i image will be upscaled to 720p. The quality of the result depends on the video processing capability of the TV.
1080p TVs and 4K Resolution
Another thing to consider is the availability of 4K resolution content sources. Most 1080p TVs can’t accept 4K resolution input signals. Unlike 480p, 720p, and 1080i input signals, which a 1080p TV can scale up and additionally adjust for screen display, they can’t accept a 4K resolution video signal and scale it down for screen display.
1080p TVs, Smart TVs, and HDR
In addition, there are a small number of 1080p TVs (mostly available from LG in the U.S. and Sony in Europe) that also include HDR decoding. This provides enhanced brightness and contrast encoded on specific content, including select video games. HDR is most commonly found on 4K and 8K TVs.
The Bottom Line
Although there are TVs with various default display resolutions, as a consumer, don’t let this confuse you. Keep in mind the space you have available to place your TV, your viewing distance and angle, the types of video sources you have, your budget, and how the images you see look to you. If you are considering the purchase of an HDTV smaller than 40-inches, the actual visual difference between the three main high-definition resolutions, 1080p, 1080i, and 720p are minimal if noticeable at all. The larger the screen size, the more noticeable the difference between 1080p and other resolutions. If you are considering a purchase of an HDTV with a screen size of 40-inches or larger go for at least 1080p – However, 1080p TVs above 40-inches in size are getting harder to find as 4K in smaller screen sizes, such as 40-inches is becoming more affordable. In fact, it is becoming common to find 1080p TVs in the 32-inch size. Definitely consider 4K Ultra HD TVs in screen sizes 50-inches and larger. If you really want to push your budget, 8K TVs have arrived on the scene and can be found in screen sizes ranging from a high of 98-inches and a low of 55-inches. However, at sizes below 70-inches, the difference between 4K and 8K is very hard to see.
