Understanding Resolution, Dot Pitch e.t.c?

[mikehende]

Ok guys, I am up to the Video section of MM's book and from my first reading, he doesn't explain this well so I am taking Pete's advice here from my last run-in with MM and the command line section, which was to immediately try different sources and not frustrate myself trying to understand MM's explanations.

I need some great online tutorials for this, any links anyone? My searches have not turned up anything satisfactory so far, also if any of you here has a real in-depth grasp on these issues then I could definitely use your help!

P.s. I want to master this section so I'll leave no stone unturned, this means you guys most likely will get frustrated trying to explain stuff to me so PLEASE don't post if you feel this frustration coming on as your comments [unintentionally] might be offensive, thanks.

[kern]

Mike,
Heres a primer on LCD monitors:

Here's a few important facts about LCD Monitor's:
Screen Size, Resolution and Refresh Rate
Unlike a CRT, an LCD's diagonal size (corner to corner) is the visible viewing space.
APPROXIMATE CRT to LCD sizes are: 17"CRT = 15"LCD, 19"CRT = 17"-18.4"LCD, 21"CRT = 19"-20"LCD.
LCD's have a maximum viewing resolution due to a fixed number of pixels on the LCD screen. The number of physical pixels depending on an LCD's maximum resolution is approximately: 1024x768 - 786,000, 1280x1024 - 1,310,000, 1600x1200 - 1,920,000.
Usual optimum resolutions for LCD's are: 15" 1024x768, 17"-18.4" 1280x1024, 19" 1280x1024 - 1600x1200, 20" 1600x1200. Using a lower setting will reduce image quality. Keep in mind you should match your LCD to your video card. If you purchase a 17" LCD and your video card cannot handle games at 1280x1024, then you will reduce overall image quality and increase the chances of streaking and ghosting.
The Refresh Rate is no longer a concern, since LCD’s do not flicker like CRT’s at low refresh rates. The optimum refresh rate for LCD's is 60hz (a setting that would give you a headache within minutes on a CRT). Most LCD’s will support refresh rates up to 75hz when using an analog connection, although in a side by side comparison of an LCD running at 60hz and one running at 75hz, you would not notice a difference.

Response Rate, Color Depth and Contrast Ratio
The Response Rate is made up of two figures “Rise” & “Fall” (-tr & +tf), added together will give you the total response rate of the LCD. This total will range from a "fast" 16ms, right up to a "slow" 50ms. You want an LCD with a lower response rate as possible, the lower the response rate the quicker each individual pixel can move from white to black (or vice versa), and the quicker the screen can be re-drawn. Games or other fast moving images such as DVD’s require a fast response rate- 30ms max, 25ms prefered, but the LOWER the better. The higher the response time the more likely your display will be subject to ghosting and/or streaking. This is one of the most important factors in the purchase of an LCD, especially if you are a gamer. Read the full spec sheet since some manufacturers "advertise" a low response rate using only the “tr” time, and you still need to add the “tf” time to get the total response time, so an LCD advertised as 25ms may become 40ms once you read the full specs.
The majority of LCD's display from a Color Depth of 15.2 million colors (true color). However those LCD's which have a response rate of 16ms use a slightly different method- showing two alternate colors to give you "true color". There is no noticeable flicker on screen because of the two colors being shown, but if you demand 100% accurate color matching then you may be better off with a CRT for the time being.
The Contrast Ratio is the difference in light intensity between the brightest white and the darkest black. A higher contrast ratio represents a better color representation than on an LCD with a lower contrast ratio, so the higher the contrast ratio the stronger colors will look, and the better the detail will appear. LCD's will range from 200:1 to 700:1. At least 350:1 to 400:1 should be the minimum considered.

Viewing Angle
Viewing angles are measured in degrees Horizontal & Vertical. The Viewing Angle is no longer a major issue when purchasing an LCD since modern LCD's are approximately 160° x 160°, giving a wide enough viewing angle for more than one person to look at the screen. Although some have higher viewing angles, you will still get the best possible image quality and color clarity if you sit dead-center on the screen.

Analog (D-Sub) Vs Digital (DVI)
All LCD's have an Analog connection, most now have a Digital port too. To use this Digital port your video card must also have a DVI port. You will also need a DVI cable to connect the video card and LCD. If your LCD ships with a DVI cable, use it since the manufacturer will have made sure it is suitable for the unit.
If your LCD does not come with a DVI cable you need to make sure you get one that can support the maximum resolution of the LCD. A cable designed for a 15" LCD will not provide the correct bandwidth needed for a higher resolution 17" LCD, and will result in poor picture quality and the image will shake. Best to buy a cable capable of a higher bandwidth than you require. The Belkin DVI Single-Link cable, for example, provides more than enough bandwidth for panels running up to 1600x1200. With DVI you are using a true digital connection from one end of the connection to the other, which allows improved image quality and “sharpness” of the screen. With the D-Sub connection you are going through a couple of conversions, digital to analog and then further down the line analog back to digital, and image quality suffers.

Brightness & Gamma
Brightness of LCD's is measured in cdm-² and the majority of LCDs are around 250cdm-² - 260cdm-². LCD's are very bright by nature and are usually factory set at 100 Brightness, which may hurt your eyes in a room with low ambient lighting. On LCD's with a Brightness control, set to 50- otherwise, increase ambient lighting.
Games which are rather dark may not appear too well on an LCD. If you are having this problem you will probably need to adjust the gamma settings.

Backlight's & Backlight Leakage
A backlight makes an LCD bright. Because the backlight is so bright this can cause "backlight leakage" around the sides of the panel. This will appear as a slight white "haze" around the edges of a black or dark screen. Unfortunately there is no way to totally prevent this and all TFT's suffer from this to some extent. During normal use and on bright backgrounds and games, this "haze" will not be noticeable. Backlights do fail, but estimated lifespan is >40,000hrs, or 4.5yrs on 24/7, or 9yrs on 12/7 (average use).

Monitor "Burn-In"
An LCD will be as bright and clear after three years as it was the first time you switched it on. From time to time you may notice that if you display the same image on your LCD for numerous hours, once you switch the panel off or the next day you switch it on, it is possible that the last image can be faintly seen. With a CRT this damage, called "Burn-in", is permanent, however on an LCD it is not. If this happens, simply continue to use the LCD or leave it on a screensaver for approximately the same number of hours that you displayed the static image - the after image will initially fade and then vanish leaving no permanent damage to your LCD.

Dead or Lazy Pixels
Dead sub-pixels are not uncommon on an LCD. A dead sub-pixel is one that is usually stuck on one particular color, either red, green or blue and will remain that color no matter what it should be. These pixels are most noticeable on a very dark or black background and are less visible on a lighter one. It is not uncommon for a brand new LCD to have one dead pixel. Most manufacturers allow 5-10 dead pixels before they consider your display faulty.
If your new LCD has one or more stuck pixels the first thing to do is to find out if they are “dead” or simply “lazy”. First connect the display via an analog connection and set the display to the fastest refresh rate possible (usually 75hz). Now get the pixels changing color, use a screen saver, a game, anything that gets the pixels changing color rapidly. What you may find was that the “dead” pixel was only “lazy” and after 10-15 minutes of use you may find all of your pixels are normal.

Lastly, visit your local shop to see LCD's in operation, preferably the exact units you are considering purchasing, and if possible use the applications or games that you use in a normal day, or view a DVD or two. It's easy to be impressed with the image quality on a game you use once a month, but how it looks with a game you play or applications you use daily are most important. A Display that looks good to one person’s eyes may not be so good to another person. If you cannot see the actual display you are interested in, then make sure you purchase from a vendor that will allow you to return the panel free of a restocking charge.

ClearType
Feature in Windows that eases the edges of icons and windows and is designed to be used with an LCD display. To activate in XP- Display Properties, Appearance, Effects, in the "smooth edges of screen fonts" drop-down menu select "ClearType".

[kern]

Heres some "video" definitions:

Active Area/Effective Area: In the viewing area of the LCD glass, the dimensions of the perimeter of the conductive area.
Bezel: A frame of plastic or metal, fitting around the LCD glass, to protect the edges of the glass.
Cell: See subpixel.
Cell Gap: The space containing liquid crystal fluid between the two pieces of glass.
Cold Cathode Backlight (CCFT): In LCD graphic modules, a type of fluorescent backlighting or edge lighting. One or more fluorescent lamps behind the LCD panel that provides the light that is either blocked (black) or passed (white) by the LCD cell.
Contrast Ratio: The difference in luminance between a white square centered on the screen and the black surrounding area.
DCE™: Digital Chroma Enhancement produces rich, saturated colors when video and moving images are displayed.
Digital Controls: High-tech SoftTouch digital controls electronically sense the slightest touch for easy adjustments of size, position and tuning at all resolutions.
Dot/Pixel (Picture Element): The smallest active element that forms all text and graphics on the LCD screen.
Ghosting: A phenomenon occurring when voltage from an energized element leaks to an adjacent OFF element and turns the adjacent element partially ON. Also, the temporary trail left by a moving object on a "slow" LCD panel.
In-Plane Switching (IPS): A liquid crystal technology in which the alignment field is generated from electrodes located on a single substrate rather than on opposite sides like more conventional (TN) panels. The main advantages IPS are greater viewing angles and greater contrast ratio.
Latency: See ghosting.
Liquid Crystal Fluid: Having properties of both a solid and a liquid, it consists of rod-shaped bipolar molecules that are capable of twisting polarized light when in the OFF state.
Module: An LCD glass connected to a PCB with drivers on board. It may also have controllers, temperature compensation circuits, or other features.
Native resolution: The actual number of pixels forming the LCD panel. This is typically expressed as the number of pixels in a line by the number of lines, e.g. 1024x768. The native resolution may also be expressed in megapixels, which is calculated by multiplying pixels per line by total lines.
Nit: A measure of luminance equal to 1 candela per square meter. Higher numbers indicate brighter displays.
OnView® Technology: All screen adjustments are made via an on-screen menu using simple controls.
OptiSync® Technology: Supports multiple inputs that feature precise display synchronization to any analog or digital computer signal for exceptional configuration flexibility.
Ø-Touch™AutoTune™: Automatically provides the best image by monitoring the signals from the computer and optimizing the monitor settings.
PerfectPortrait® Software: Enables the monitor to pivot easily between landscape and portrait mode.
Pitch: The center-to-center distance between subpixels of the same color.
Pixel: Picture element (see Dot/Pixel).
Saturation Voltage: RMS voltage required to turn fluid to 90% ON.
Scaling: An operation performed by a digital signal processor to fill the screen with an image not being displayed in the native resolution of the LCD panel.
Subpixel: A red, blue, or green liquid crystal shutter. One subpixel of each color forms a pixel capable of displaying as many as 16.7 million colors.
SuperClearMVA (Multi-Domain Vertical Alignment): Combines SuperClear screen technology digital with a liquid crystal technology in which each subpixel is subdivided into four regions in which the liquid crystal molecules align at angles to each other. The advantages of MVA are wider viewing angles and faster video response than TN or IPS.
Threshold Voltage: RMS voltage required to turn fluid to 10% ON.
Transmissive: An LCD which does not have a reflector or transflector laminated to the rear polarizer. A backlight must be used with this type of LCD configuration.
Twisted Nematic (TN): A type of liquid crystal in which the alignment surface, and therefore the liquid crystal molecules, is oriented 90 degrees from each surface of glass.
Video Response (response time): The time it takes to turn a pixel from OFF to ON to OFF again. A low number is desirable to display moving images without ghosting.
Viewing Angle: A cone perpendicular to the LCD in which the contrast ratio exceeds 10.
Viewing Area: The actual area that can be illuminated when the entire screen is turned ON (white).
ViewMatch®: Allows users to adjust the color temperature and individual color intensity for easy screen-to- print matching.

[mikehende]

Thanks ROB, this helps but I still need something more in-depth concerning Pixels, dot pitches e.t.c., remember that for "my" purpose this is for Comptia certification.

[mikehende]

Don't know how I could have forgotten about this site?

http://www.pcguide.com/ref/crt/res.htm

[mikehende]

Aaaay, looks like I will have to use multiple sources for this topic. Here's a good one for Dot Pitch, Resolution and Refresh Rate if anyone's interested:

http://www.folder101.com/CompHardware/Notes/lecture2/MonitorSpecs/MonitorSpecs.htm

Here's one for LCD:

http://www.sencore.com/newsletter/Oct04/LCDTechnology.htm

[mikehende]

Surprise surprise, actually I got through this section very well, Pete, if you read this post, your method worked extremely well here, by immediately reading through different tutorials, this section went by very smoothly, I even got all 10 questions correct at the end of the chapter.

I really feel I must apologize to EVERYONE here for having posted this in my inital post

"P.s. I want to master this section so I'll leave no stone unturned, this means you guys most likely will get frustrated trying to explain stuff to me so PLEASE don't post if you feel this frustration coming on as your comments [unintentionally] might be offensive, thanks."

Please note that I did so due to bad experiences on another Certification forum where guys were trying to help explain the very difficult "Command line" section and one or two of them started getting borderline insultive so I left that forum, I do understand that these one or two guys were trying to help me and felt frustrated that I could not understand their explanations but insults is not the way to teach anyone, just thought that I would explain this here so I don't ever run into that problem on this site, thanks.

[PeteF]

Surprise surprise, actually I got through this section very well, Pete, if you read this post, your method worked extremely well here, by immediately reading through different tutorials, this section went by very smoothly, I even got all 10 questions correct at the end of the chapter.


Mike,
I'm glad to hear that. Learning from books or articles can be difficult
at times, but going to a few totally different sources on the same topic
often helps because what one author leaves out, another author might
fill in, making the point otr topic very clear.

Another similar technique I've used sucessfully goes towards selecting
a book to study on a given topic. I'll visit the public library or a book
store with intention to obtain a book on a given topic. I'll have one
or two questions written down that I need answered. Then I'll grab
3 different books off the shelf on the same topic and by different
authors, and use the table of contents and index to try to find the
answer to my questions. I'll look up the same question in all 3 books.
The book that best answers my question and was easiest to use to
locate the info, is the book I obtain for further studies.

---pete---

[mikehende]

I'll have one or two questions written down that I need answered. Then I'll grab 3 different books off the shelf on the same topic and by different
authors, and use the table of contents and index to try to find the
answer to my questions. I'll look up the same question in all 3 books.
The book that best answers my question and was easiest to use to
locate the info, is the book I obtain for further studies.
---pete---

I don't know if this will work for me Pete because I can't find one single source that answers everything for me but here we are talking about 2 different things, Books vs the net, I use only the net and PC Guide is the best overall I have come across so far where tutorials are concerned but I have to go elsewhere every now and then. I am at page 850 in MM's book and closing in, my plan all along was to read the book from beginning to end making sure I understand every single page along the way then when I am done, now I would deal strictly with questions from every exam I can get my hands on.

What I don't understand is why you would prefer to use Books as opposed to the net? I would think that the net would have a heck of a lot more info available?

[Terry Hanushek]

Mike

What I don't understand is why you would prefer to use Books as opposed to the net? I would think that the net would have a heck of a lot more info available?
I have found that when I use a yellow highlighter on an Internet article, my monitor gets all messy. :D

Terry

[mikehende]

Good point Terry but I do the same by re-creating my own tutorials and printing them for future reference! So I guess this topic now has a new twist, whci is better, net or books?

[dale@fcg]

Rob,
thanks. Man, did you type all that out, or was there some copy and paste or speech to text?

[PeteF]

What I don't understand is why you would prefer to use Books as opposed to the net? I would think that the net would have a heck of a lot more info available?

It depends what the topic is, but most times I find a text book superior to
to the net because a book is better organized. Reading comprehension
is also much better with a book. The net is good for some things but
few websites are are as wel thought out and organized as a published
textbook.

On the other hand, the net is better than books for topics that involve
the latest up to date info.

---pete---