All About: Monitors
Although we interact with a monitor of some format nearly every day they are still surrounded by a surprising amount of technical jargon. As monitor technology evolves, so does the language used to describe certain aspects of the display and as with most things, it is useful to understand your current equipment to help inform your next upgrade. See the page glossary for any terms you are unsure of. The first thing to consider is the change over the last decade from heavy, square boxes to the altogether ergonomic and aesthetically please flat-screen monitors. Moving from CRT (cathode ray tubes) to the now relatively standardised LCD (liquid crystal display) has enabled a generation of energy efficient, variable size displays units.
With variable sized display units comes resolution. This is the number of dots, or pixels contained within your screen and this will affect the image in front of you. Resolution can be measured in different ways but generally a higher resolution will equal greater clarity of image. For example, your phone resolution will have increased greatly over the last decade: the iconic Nokia 3310 featured a whopping 84x84 monochrome display – excellent for Snake II – whereas many current smartphones are beginning to support a 1080x1920px display giving users a High Definition experience in their pocket. As monitor size has increased over the year’s display standards have changed accordingly:
- XGA (Extended Graphics Array) = 1024x768
- SXGA (Super XGA) = 1280x1024
- UXGA (Ultra XGA) = 1600x1200
- QXGA (Quad XGA) = 2048x1536
- WXGA (Wide XGA) = 1280x800
- WSXGA+ (Wide SXGA plus) = 1680x1050
- WUXGA (Wide Ultra XGA) = 1920x1200
- WQHD = 2560 x 1440
- WQXGA = 2560 x 1600
- QSXGA = 2560 x 2048
The pixel resolutions displayed here influence the standard of image available to your monitor. The second major influence over image clarity is the size of the actual screen itself. Aspect Ratio dictates the ratio of width to length of a screen. The de facto monitor aspect ratio used to be 4:3. However the advent of widescreen monitors has seen this change to 16:9, allowing higher resolutions to be used. Paired with this is the actual Screen Size. This measurement is usually taken from diagonal corners but differs for CRT and LCD monitors:
- CRT: Measure from the true extreme of the corner, outside the monitor casing to the opposite diagonal point.
- LCD: Measure from inside the monitor casing, diagonally across the screen from diagonal to diagonal.
This discrepancy equates a 17” LCD monitor with a 19” CRT, so if attempting to purchase a CRT be sure to investigate the Viewable Screen Size for a true indication of what you are purchasing. Monitor sizes are increasing though popular sizes vary from 15” – 21”, with some excellent offerings appearing on sizes up to 40.” We must state here that resolution is directly affected by display size. Coming back to our Nokia 3310, the 84x84 pixel display would be unreadable stretched onto a modern 5” smartphone due to the total pixel spread.
Monitor Colour Depth
Now we understand resolution, pixel spread and display size we can consider the Colour Depth. This is still affected by the resolution but in a different manner and is dictated by the specifications of the Graphics Processing Unit (GPU) of the computer. Virtually all varieties of colour are decided by the number of bits available. You may have encountered terms such as ‘32bit’ and ‘64bit’ when considering operating systems, processors (CPU) or games consoles i.e. Nintendo 64 – the 64 indicating its power. For example, most LCD monitors have a bit depth of 32 (referred to as True Colour), allowing for 16, 777,216 colours to be displayed across the liquid crystal formation. Bit depth moves in multiples of 8 and preceding 32 bit was 24, 16, 8, 4, 2 and 1.
- 32bit: 16,777,216 (True Colour + Alpha Channel)
- 24bit: 16,777,216 (True Colour, SVGA)
- 16bit: 65,536 (High Colour, XGA)
- 8bit: 256 (VGA)
- 4bit: 16 (EGA)
- 2bit: 4 (CGA)
- 1bit: 2 (Monochrome)
Strictly speaking, 32bit is an enhanced graphics mode used in digital video, video gaming and animation techniques to allow for increased depth of colour through the enabling of translucence in images though monitors will by and large all be completely functional utilising 24bit colour standards. Advanced GPU units can now support HDMI (High Definition Multimedia Interface) output with a spectrum of 1.073 billion colours, so long as the monitor itself can process the exacting resolution (1920x1080 or higher).
For all of this to work there are specific varieties of cables used to connect the monitor (depending on type) and computer and can be found in analogue or digital format. CRT monitors utilise an analogue connection as standard, requiring information to be constantly delivered in waves, rather than the digital format which utilises pulses in the binary system format.
The standard cable many individuals will have encountered is the 15-pin VGA cable but does not allow for digital transmissions. For this, the DVI standard was developed to enable digital transmissions to digital monitors (DVI-D – digital only format) but also comes with an analogue flavour (DVI-I – digital and analogue) to enable cross generation compatibility. For your monitor to achieve its optimum picture quality it is important to note the types of input available and to choose the appropriate cable. For HDMI quality images, a specialised HD cable is required.
Monitors have come a very long way since their inception and will continue to evolve in the coming years. We are now seeing the advent of 4K Ultra HD (3840x2160) and 8K Ultra HD (7680x4320) in television manufacturing and it is not uncommon in commercial or industrial situations to find large monitors in use that far exceed any monitor in use across most residential settings.
Other Monitor Parameters
Some other parameters to consider when choosing a monitor:
- Viewing Angle: Maximum angle images can be clearly viewed, measured in degrees e.g. 167° viewing angle.
- Luminance: Measures the luminous intensity of the monitor e.g. the numerical number of light projected by the screen.
- Refresh Time: The number of time in a second that a display is illuminated. This is typically a very low number measured in millionths of seconds e.g. 7m/s.
- Response Time: Limits the refresh time by dictating the time between active, inactive and back to active. Again, measured in millionths of a second with lower times relating enhanced picture transition.
- Power Consumption: A measure of power consumed by the monitor. Can be useful to know if using non-traditional sources of power.