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Thread ID: 70297	2006-06-28 07:54:00	Viewsonic VX922 Monitor	ruup (1827)	PC World Chat

Post ID	Timestamp	Content	User
466909	2006-07-30 01:50:00	Regarding the VX922, it is indeed 16.2 million colours :thumbs: A comprehensive spec sheet can be found here www.newegg.com	RandomCarnage (9359)
466910	2006-07-30 01:55:00	From compreviews.about.com 8-Bit vs. 6-Bit Color Depth The color range of a computer is defined by the term color depth. This means the total number of colors that the computer and display, in tandem, can display to the user. The most common color depths that users will see when dealing with a PCs are 8-bit (256 colors), 16-bit (65,536 colors) and 24-bit (16.7 million colors). True color (or 24-bit color) is the most frequently used mode now as computers have attained sufficient levels to easily work at this color depth. Some professional use a 32-bit color depth, but this is mainly used as a means to pad the color to get more defined tones when rendered down to the 24-bit level. Speed Versus Color LCD monitors have encountered a bit of a problem when it comes to dealing with color and speed. Color on an LCD is comprised of three layers of colored dots that make up the final pixel. To display a given color, current must be applied to each color layer to give the desired intensity that generates the final color. The problem is that to get the colors, the current must move the crystals on and off to the desired intensity levels. This transition from the on to off state is called the response time. For most screens this was rated around 25ms. The problem is that many LCD monitors are used to watch video or motion on the screen. With this 25ms time frame for transition from on to on states, pixels that should have transitioned to the new color levels trail the signal and result in an effect know as motion blurring. This isn't a problem if the monitor is being used with applications such as productivity software, but with video and motion it can be jarring. Since consumers were demanding faster screens, something needed to be done to improve response times. To facilitate this, many manufacturers turned to reducing the number of levels each color pixel render. This reduction in the number of intensity levels allows the response times to drop but has the drawback of reducing the overall number of colors that can be rendered. 8-Bit vs. 6-Bit Now color depth was previous referred to by the total number of colors that the screen can render, but when referring to LCD panels the number of levels that each color can render is used instead. This can make things difficult to understand, but to demonstrate, we will look at the mathematics of it. For example, 24-bit or true color is comprised of three colors each with 8-bits of color. Mathematically, this is represented as: * 2^8 x 2^8 x 2^8 = 256 x 256 x 256 = 16,777,216 High-speed LCD monitors typically reduce the number of bits for each color to 6 instead of the standard 8. This 6-bit color will generate far fewer colors than 8-bit as we see when we do the math: * 2^6 x 2^6 x 2^6 = 64 x 64 x 64 = 262,144 This is far fewer than the true color display such that it would be noticeable to the human eye. To get around this problem, the manufacturers employ a technique referred to as dithering. This is an effect where nearby pixels use slightly varying shades or color that trick the human eye into perceiving the desired color even though it isn't truly that color. A color newspaper photo is a good way to see this effect in practice. (In print the effect is called half-tones.) By using this technique, the manufacturers claim to achieve a color depth close to that of the true color displays. How to Tell if an LCD is 8-Bit or 6-Bit This is the biggest problem for individuals who are looking at purchasing an LCD monitor. Most manufacturers do not list the color depth of their display. Even fewer will list the actual per-color depth. If the manufacturer lists the color as 16.7 million colors, it should be assumed that the display is 8-bit per-color. If the colors are listed as being 16.2 million or 16 million, consumers should assume that it uses a 6-bit per-color depth. If no color depths is listed, it should be assumed that monitors of 12ms or faster will be 6-bit and the 20ms and slower panels are 8-bit. Does it Really Matter? This is very subjective to the actual user and what the computer is used for. The amount of color really matters to those that do professional work on graphics. For these people, the amount of color that is displayed on the screen is very important. The average consumer is not going to really need this level of color representation by their monitor. As a result, it probably doesn't matter. People using their displays for video games or watching video will likely not care about the number of colors rendered by the LCD but by the speed at which it can be displayed. As a result, it is best to determine your needs and base your purchase on those criteria.	Mackin_NZ (6958)
466911	2006-07-30 03:50:00	A couple of my friends bought that monitor & they are very impressed with it. How notisable is the difference between 2ms, 4ms & 8ms?	Greven (91)
466912	2006-07-31 01:00:00	It is effectivly the refresh rate . Where a CRT paints the screen line by line, a LCD dumps the entire image at once over the whole screen . While there is a big difference between grey to grey or black to white or a rise and fall test, generally the speed can be equated to how many times the image on screen can be refreshed, with 2ms being 500 times a second . This should not be taken to literally, as real speeds are somewhat slower than this, but the 2,4,6,8 ms etc listed time is a reasonable indicator of refresh speed relative to other listed times . In the case of the VX922, it trades off colour depth and contrast for high speed "gaming" applications where "ghosting" (i dislike the term) or after image is negated but at a cost in quality . On some slower LCD's, any rapid lateral movement such as spining around quickly can cause a halo effect to be visible around the object as the crystals can't realign fast enough to produce a clear image . 8 ms screens are usually true 8 bit, 16 . 7 million colour and have high contrast allowing for near true black to be displayed (difficult cos of the LCD back light) Faster than 8ms screens are usually 6 bit colour, (6+2bit) but can display an effective gammut of around 16 . 2 million colours due to the fast response time fooling the human eye faking colour by having adjacent pixels using different colours to trick our sences into seening a 3rd colour . To a large extent, fast screens can get away with this, but the reality is closer to 256,000 colours being rapidly used to simulate 16 . 2 million . Unless you play games where speed is a priority, an 8ms screen with true 8 bit 16 . 7 million colours and high contrast (800:1 or better) is the way to go .	RandomCarnage (9359)
466913	2006-07-31 02:10:00	Between 2ms 4ms and 6ms there is probably not a lot of difference (if any). Manafacturers response times ratings are usually rubbish anyway, as they pick the fastest time reached, not the average response time.	mejobloggs (264)
466914	2006-07-31 21:19:00	Where do they hide the information that says if the monitor is 6 bit or 8 bit? I was considering buying a VX924 (or 922 if a 924 is too hard to come by), but 8ms is still a pretty good response time & if someone can reccomend a 19" LCD with 8ms or better response time that is 8 bit rather than 6 bit, I will go with that instead.	Greven (91)
466915	2006-07-31 22:03:00	Response times not withstanding, IMO unless you have an 8bit and a 6bit monitor sitting side by side, you'd be hard pressed to tell the difference.	Mackin_NZ (6958)
466916	2006-08-01 11:44:00	Consider then the Viewsonic VX2025wm. It is a 20" wide screen 16x10 with 8 bit colour (16.7 million) and 800:1 contrast. It has a listed response time of 8ms. This monitor has had many favourable reviews that I have seen during my research into the 922. My over all conclusion is that the 922 is a very good gaming monitor which virtually eliminates haloing/after image. The colour seemed very good all in all, given its 6 bit herritage, but the one main failing if you will was its ability to render true black. This may limit its satisfaction utility to some extent, especially if you prefer high quality images over super fast (gaming) applications. You are right to say that an 8ms 19" (or larger) screen is fast enough for most applications, inc. games, and it is likely that you will not notice any significant after image except perhaps in fast lateral turns (spinning around quickly in a high detail game). I suggest you look into the Viewsonic 2025wm rather than the vx922. I get the feeling it will suit you better. (edited to change model to 2025wm. I had mistakenly listed 2025ws)	RandomCarnage (9359)
466917	2006-08-01 21:19:00	Sounds good, but it is $250 more expensive than the VX922. Even the 922 is at the high end of my budget	Greven (91)
466918	2006-08-02 07:31:00	www.pricespy.co.nz Check this out. Very good site for finding cheapest prices in country.	RandomCarnage (9359)
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