So a huge break down and recapping all the great info FreedomGundam has shared and then More information that fits into the discussion.
Response time: How fast a pixle can change or fill. Measured in Microseconds. Faster Response time means less ghosting or motion blur.
Refresh Rate: how many times the image refresh or change in one second, Measured in hertz. Hertz is how many cycles per second. NTSC standard is 60 hz, Pal is 50.
**Input Lag/ Display Lag: **The delay from input compared to the output. Example: In Super Mario Bros, its time time from when you hit that jump button til you see Mario Jump. Also measured in Microseconds.
This is always left out of the Display’s Advertised specs.
**Frames per second: ** Often incorrectly confused with Refresh rate. In a video these are the rate of animation changes in a video (referred to as a frame). Typically most movies and video are displayed at approx 24 to 30 frames per second. Frames per second (FPS) is also used as a term in gaming, how often a computer’s CPU Plus Graphics Hardware (GPU) draws a new image of animation. The “GOLD” standard for this is 60 frames per second to MATCH the Refresh rate of most displays.
**Image Post Processing: ** The additional computer processing a display does to render the image displayable on a LCD screen display.
The next few all fall under Image Post processing, all effects display lag. This does not cover all image post processing.
**DAC or Digital to Analog Conversion: ** the change or conversion from a Digital to Analog Signal and vise versa. Used to allow for digital displays to accept Analog signals. Often this is handled by a chip separate from the rest of Image Post processing. Depending how good the DAC is, would effect if you get additional input lag or not.
**Aspect Ratio: ** Refers to the dimensions of a screen or display. With Standard Definition displays most screens are 4:3 or for every 4 measurements wide the screen is only 3 measurements tall.
With Movie Cinema wide screens and HD displays you have 16:9 or Wide screen format, the image is 16 measurements wide for every 9 measurements tall.
**Scalling: ** The Process where a image is re-sized to fit a Digital display. This is for both to match the image to the resolution of the display as well as to correct for aspect ratio differences. This process is automatic and “Near Instantaneous” in Analog CRT Displays.
To make a 4:3 image fit a 16:9 screen (and vise versa) there various methods to go about this,
Stretching: The Image is stretched to fill the whole screen.
Letter Box: Black bars are added to the image to make the image fit the screen without stretching. For 4:3 images on a 16:9 display will produce 2 black bars on ether side of the screen.
Postage Stamp: Taking Letter box to the extreme by putting black around the whole image, top, bottom and sides. This has the effect of making the image seem smaller than it should be.
Zooming: the image is zoomed in, often cropping out parts of the image that extends beyond the screen.
**Interlace: ** Interlaced video is a technique of doubling the perceived frame rate without consuming extra bandwidth (this includes analog formats, even over the air), Only half the image is displayed at any one time each frame, as the image is scanned in every other scan line is skipped, on the next scan refresh the scan lines that were skipped are scanned in.
**Progressive: **The Entire image is displayed at one time,
**Deinterlacing: ** The Process of turning an image from a Interlaced to a Progressive image.
**Line Doubling: ** Another method to deinterlace a image, Every line is doubled on each frame, this does cause a side effect called image craw, where the edges of objects on screen seem to "crawl"
The process is also used to make 240p resolution images fit a 480p with little or no processing.
This only applies to TVs, Monitors, Displays and video converters/ external video processors. When a video feed is deinterlace without Line doubling you produce a visually better image but you also add 2 frames of display lag as the image processing needs both interlaced frames to compile a single progressive image.
Combing : A Visual artifact or defect from Deinterlacing. A noticeable comb-like effect is seen, especially if the video is paused.
- Image is from Wikipedia
Game Mode : A visual display setting in some HDTVs that tries to bypass much of the unnecessary Image Post processing to reduce Input lag/ image Display Lag.
PC Mode : Display Settings that used when a PC is connected to a HDTV, similar to Game Mode much of the image post processing is bypassed (in many displays even more so).
In Some displays to get the least amount of input lag both modes are needed.
For HDMI/DVI-D input PC mode, this works as expected. HDMI and DVI is so similar in format that many HDTVs would often consider a PC video source DVI even if the video coming from a HDMI source.
For VGA or DVI-A (DVI-A is just VGA via a DVI connector) the video input has to be processed by the DAC first. If your Display has a quality DAC there no issues. If your HDTV has a terrible DAC you will get Input lag.
Careful with going with the VGA description as it used to describe two different things. VGA stands for Video graphics Array
- (adopted/blanket term) VGA as in the connector type, the 15 Pin DE (DE-15) sized Sub-D connector, sometimes called HD-15 (high density) and incorrectly called DB-15. (DB connectors are 25 pin connectors) used to carry RGB VH 31Khz carrier frequency analog video signals.
- Video graphics array, refers specifically to the display hardware first introduced with the IBM PS/2 line of computers in 1987 640x480 pixels with 16 or 256 colors.