LCD vs CRT displays

CRT or LCD? Which one is better? It seems to be an argument discussed in nearly every computer trade magazine at some point in time. What are we to make of all this information being thrown at us about the different technologies? Since we here at LaCie have to answer many questions and concerns on this issue daily, we put together this e-mailing to inform all LaCie VARs about the two technologies, and how they perform the job they are designed to do. The information in this e-mail will bring up some points which you should be aware of when helping your clients select their next monitor.

Since LaCie manufactures graphic monitors we will approach this article with the frame of mind that image quality and colour accuracy is a very important factor in the selection process. So lets break down of the two technologies in an attempt to put the difference between the two into perspective. Note the links at the end of this e-mail for some additional Internet resources on the subject. These links have technical information with actual calibrated results and exact measurements in a direct comparison of LCD and CRT monitors.

LCD
LCD screens as little as 5 years ago were not pleasant to use even in their most common application on laptop computers. The evolution of LCD technology over the past few years tightened the dot pitch, pixel response time, colour range, and brightness of LCD screens. Today we have LCD
monitors which look bright, sharp and colourful.  Which is the main reason why they are becoming more widely offered by many companies, including LaCie. They are small in size and offer a small footprint. They consume less energy then CRT monitors. Their main weaknesses are related to colour accuracy, image quality, viewing angle, and pricing.

CRT
Some say that CRT technology is old and has not evolved much in the past years. Nothing could be further from the truth. While the basic principal
of how CRT tubes work has remained the same for years, the image quality has improved significantly on CRT monitors over the past few years. Introduction of flat tubes, super fine dot pitch, higher resolutions and higher refresh rates have done wonders for the CRT monitor's image quality. The fact that the technology is mature means great value in terms of price and product reliability. CRT tube colour accuracy is 2-3 times better
then that of an LCD screen. Maximum resolutions also tend to be higher then those offered by LCD screen. The main weakness everyone points to is size and weight, power consumption and refresh rate flicker.

Let's take a look at some of the recent claims made by both the LCD and CRT camps. Note that since the LCD is the challenger to the CRT technology, it is the LCD technology camp making more claims directed at dethroning the CRT.

LCD is better because it's smaller and lighter.
If the comparison is done directly on a weight scale, and lighter is better then LCD wins. LCD monitors area also thinner then CRT monitors.  Since
most users will lift their monitor once or twice a year it's not the ultimate deciding factor as size reduction has little to do with image quality.

LCD offers the same viewable size.
You see these claims often. 15" LCD is the same as 17"(16" viewable) CRT, or 17"LCD is the same as 19"(18" Viewable) CRT, etc. Well, the numbers should tell you this is not so. Not only do you get this extra 1" in viewable size on the CRT, but the CRT is able to display a higher
resolution image. A quality 17" or 18" LCD will do 1280x1024 where as a quality 19"(18" Viewable) CRT will display 1600x1200 resolution comfortably. A 30% desktop area increase over the LCD. This resolution difference is true all the way up in the direct viewable size comparison
chart between LCD and CRT.

CRT monitors have annoying flicker.
Due to the physical difference between LCD and CRT technologies it is true that CRT monitors can flicker. However, if you are currently using a
monitor which flickers, it's time to put that Commodore 64, 286XT and Apple II on a quick retirement plan. Today's graphic cards are able to provide
high resolution and high refresh rate signal to the CRT monitors. And CRT monitors are able to refresh images well in excess of 80Hz at resolutions
as high or higher then 1880x1440. That certainly is a high quality crisp image as those of you reading this email on your LaCie ElectronBlue
monitors will confirm. Today's CRTs offer this higher performance to ensure there is no visible flicker.

What's the deal with ghosting on LCDs?
LCD screens change the image with current supplied to the transistor cells in the LCD panel. These cells take a few milliseconds to change their
state. The resulting effect is called "ghosting".  Especially visible in motion video or video games. It is the appearance of the previous frame of
a moving image after the next frame is already being played. This has improved with the response time of LCD panels, however it is still present
and visible on even the latest LCD screens.

Why do my LCD resolutions look strange?
LCD screens have a fixed resolution. Let's say you have one that's 1024x768. If you try to display 800x600, you will experience an effect
called pixel multiplication. In this case the pixels are not able to scale down evenly to the lower resolution, 2 pixels end up representing one. Also the higher dot pitch of LCD monitors in the range of .28-.31dpi further amplifies this effect. It makes the image and fonts appear deformed, and is a source of many technical phone calls. If you buy an LCD screen that is designed to work at 1024x768 resolution, you have to use it at that resolution to have a clear undistorted image. CRTs can display any resolution up to their maximum allowable resolution without this strange effect.

LCDs look bright and lively, just like CRTs
LCDs today do in fact look bright. LCD panel is really a light filter. It needs a back light source projected at the rear of the LCD panel to actually make it appear like an image. It is the intensity of this light that has improved providing high brightness levels on today's LCDs.

What about Colour?  How does LCD stand up to CRT?
The truth is that current LCD models can't hold their own when it comes to colour range they are able to display. Many LCD screens found on the market today are 18-bit, with six bits per pixel for RGB colour interpretation. That means they have a maximum colour range of 262,144 colours, instead of the 16.7 million with eight bits per pixel, 24-bit which CRTs are able to display. It is also true that CRT monitors are at least 2 to 3 times more accurate when it comes to displaying colour then LCD screens even when both are displaying 24bit colour and both are measured and calibrated with a colorimeter. CRT is able to maintain colour uniformity across the screen 2 to 3 times better then an LCD as well. The brightness in the LCD we just talked about above comes at a price. It may make the colours appear "washed out". When LCD screen is measured with a colorimeter and calibrated for colour the brightness in many cases must be reduced by half to display acceptable colour range.

Colour Temperature ­ Hot or Cold?
CRT monitors reproduce colour temperature much more accurately then LCD monitors. This is especially important to those working in the 5000K range when working with pre-press and colour.

What about the digital vs. analogue?
LCD screens are digital by design. However not all offer DVI digital connectivity. Quality LCD do have DVI digital connectors. CRTs are connected mainly with DB15 pin connector. There are CRT monitors beginning to appear with digital connectors and this feature will be introduced in the near future on all quality CRTs. Especially when DVI connectors and the likes become as standardized as DB15 is today. Digital connectivity eliminates the need for digital to analogue converters on the graphic card allowing the digital signal to be sent directly from the card to the display.

LCD screens have better image geometry.
LCD screens are flat and therefore, from the start did not have to overcome some of the challenges CRT had to overcome to be flat. LCD screens certainly display geometrically correct images. However, today's flat CRT monitors also display images with equal accuracy. CRTs of today also provide many "tweaking" menu options to have full control over the CRT image properties to ensure this accuracy.

So by now you may think that LCD has some short comings. You are not the only one. LaCie is well know for our ElectronBlue line of graphic CRT
monitors which sport many features designed to ensure highest image quality. BlueHood and BlueFrame ensure minimized light glare and reflection. BlueEye hardware calibrator to fully calibrate the ElectronBlue CRT monitor guns for accurate colour.

LaCie has spent the last 5 years educating all LaCie resellers about image quality, colour calibration, and the graphic features we have pioneered and perfected in our monitors. Exactly one year ago, we were faced with the "main stream" introductions of LCD screens. LaCie selected the best quality LCD panels found on the market to date. Super fine .28 dot pitch. 24bit colour for 16.7M range. High brightness levels, and wide viewing angle. Highest quality manufacturing process to ensure no defects (I am yet to see one with a dead pixel). We morphed this LCD screen with graphic features such as pivoting screen for Landscape and Portrait use, BlueFrame and BlueHood from our ElectronBlue CRTs. This LaCie LCD screen is known as LaCie Photon18Blue. We delivered simply the best LCD technology currently available for the demanding customer who wants LCD with the highest image quality. Those of you who have seen our Photon18Blue know the image quality and colour quality it has compared to other LCDs.

Yet with the introduction of this LCD screen, we have not eliminated our CRT line of monitors which are selling now better then ever. Why? Because even the highest quality LCD is not yet equal in quality of image and colour accuracy to a LaCie ElectronBlue CRT monitor.

LaCie ElectronBlue remains our reference point of what other monitors we introduce should live up to, regardless of technology. We worked hard to deliver a professional graphic monitor to market with image quality equal to monitors costing 4 or 5 times the LaCie price. Many of us have to
wrestle with colour, but don't want to have money wrestled away from our wallets.

Be assured that right now we are but one of a handful of companies working and developing an flat panel monitor which will address key issues about image quality,  colour accuracy, colour calibration, and image ghosting. We know that this technology is coming and we want to bring it to you when it lives up to expectations. For now, when it comes to graphics image quality and colour accuracy CRT technology is the only choice.

Here are some links we found on MacWorld's site that are very interesting. Especially the first link with colour tests and measurements with actual
results of colour measurements.

MacWorld Colour and PhotoShop expert Bruce Fraser puts CRT and LCD in the colour boxing ring. Take a look at the measurements taken with a
colorimeter of best LCD and CRT monitors on the market. http://www.macworld.com/2001/06/features/color.html

MacWorld looks at LCD Monitors.

• http://www.macworld.com/2000/07/features/flatpanelside.html

For Further Reading:

• MacInTouch.com: Flat-panel iMac report.