Choose the Best Monitor for CAD18 Mar, 2010 By: Ron LaFon
CAD 101: Arm yourself with these solid fundamentals as you set out to find the consumer- or professional-grade LCD display that's right for you.
Editor's note: For an updated look at this topic, see "How to Choose a Monitor for CAD" (Cadalyst, Spring 2013).
Your onscreen display is your window to your work every day, so selecting the right monitor is an important decision for CAD-related work. Although the common wisdom about large monitors and CAD going together holds a lot of truth, there's more to making the right selection than size alone. This article serves as a guide to help you find your path through the labyrinth of features, sizes, and options. I use these basic procedures each time I purchase a new display.
Size and Resolution
Large monitors make sense for CAD use. They require less panning and zooming — and display detail work more effectively — because more of a design shows on the screen at one time, allowing the portion being drawn to be shown in the context of the overall design.
Screen size. In general, 19" monitors are considered entry-level equipment for CAD and design work, and 21" or larger panels are deemed suitable for general work. The larger your monitor, the larger the content will display — an important consideration if your eyesight is not perfect. Bigger screens also provide larger views of segments of drawings, which is extremely useful when working with highly detailed designs.
Resolution. This measurement indicates the number of pixels per inch on your screen and determines the overall sharpness of your display. The larger the LCD panel, the higher the resolution it will have, typically. For example, my 24" LCD display has a default resolution of 1,920 x 1,200 pixels at a sync rate of 60 Hz. Most 27" monitors have this same high resolution, but the larger screen size means text and graphics details will be slightly larger and thus easier to see on screen. Modifying a display's default resolution is possible but usually results in a loss of image quality, and has the potential to distort the onscreen display of the objects you're designing.
Sync rate. Currently available LCD displays typically default to a sync rate of 60 Hz, which is enough to prevent flicker for most people.
Response time. In the simplest terms, response time for LCDs indicates the time required for the display to refresh a video image. The lower the number, the better — and note that this is not a configurable setting. Typical response times on today's LCD monitors are more than 5 ms, which is comparable to the refresh rates of older CRT displays. For smooth rotations, panning, and animations, you'll need a display that has a response time of 5 ms or less to avoid jerky onscreen movements, which I call "visual stutter." This is very important for CAD and other graphics-intensive applications in which users frequently zoom, pan, and rotate complex models in drawings and animations.
Antireflective coating. The quality of antireflective coating on the display surface is important: Glare not only makes it difficult to see the content on your screen, it also can adversely affect eyesight over time. All displays come with antireflective coating, but the quality of these coatings varies widely. Do your homework and ask questions to be sure you don't sacrifice quality in this area.
Features: Professional vs. Consumer Models
Do you need a more expensive professional-grade monitor for CAD work, or can you make do with a less-expensive consumer model? In general, professional-grade displays have faster response times, more contrast, better color rendition, and the latest technology, all features that combine to produce superior display results. But with these added features — many of which are nice to have but not be essential for most users — comes a higher price tag.
Must-have features include controls for adjusting the onscreen display, such as brightness and contrast, as well as some means of selecting which input the display is using. Nice-to-have features include an intelligently designed menu system; control buttons that, when touched, show the buttons' function on the screen; ambient-light sensors that adjust your display according to the available room light; and USB ports on the panel. For me, USB ports on the panel are a must-have, as I use them constantly to plug in devices such as external hard drives. Luxury features for me are sound bars, cowls to reduce extraneous light, and color-correction probes. But every user has a different list of musts. If you're doing color-critical work such as visualization, for example, cowls and color-correction probes might be essential features. Prioritizing features will also depend upon your budget.
High-quality monitors typically have the following connections: DisplayPort (the up-and-coming standard), DVD (typically one or two ports), HD component video, HDMI, S-Video, composites, and VGA. Most users are unlikely to use all these connections, so be sure you have the most common ones for your display.
Because DisplayPort connections are an emerging standard, it's probably wise to select them as well.
Some CAD users prefer a multiplemonitor setup. The increased screen real estate of side-by-side monitors means you can display twice as much of the drawing at one time, or design on one monitor while using the other to display menus, text screens, or even e-mail.
The display area of these configurations is limited by the size, resolution, and ultimately, the number of monitors. You can mix both the type (CRT or LCD) and the size of the monitors, with the operating system managing the resolution of each independently.
You'll need either a video card that supports two discrete outputs (dual-head) or two separate graphics cards. Depending on your motherboard, you might be able to use the graphics card on the motherboard plus an additional graphics card. The drawbacks of a multiple-monitor setup are the extra cost and system complexity.
An alternative to a double-monitor setup is Eizo Nanao's FlexScan SX3031W, a 29.8" wide-screen monitor. Its picture-by-picture function divides the screen into equal halves, each 1200 x 1600, with no center bezel. Input from two different computers (such as a Windows and a Mac) can be displayed, making it possible to work on two tasks simultaneously without having to toggle back and forth between inputs.
Prices for good-quality LCD displays range from approximately $125 to $2,000, depending upon the panel's size, features, and stand flexibility. In general, consumer-level displays cost less than $900; the more capable professional models go into the upper price ranges. Can you get by with a $125 consumer-grade monitor for CAD work, or do you need a professional model? The answer depends on the complexity of the work you do and your personal requirements. An inexpensive model that has good resolution and response time might fit the bill for 2D drafting. For digital-content creation (DCC), you might require a high-end display for its color accuracy, potentially greater color depth, and its ability to use color correction hardware to fine-tune the color.
By all means, look for sales. Office supply superstores such as Staples and Office Depot often sell high-quality monitors at bargain prices — watch web sites and local ads, and sign up for rewards programs to receive special offers and coupons that can reduce those prices even further. Also consider refurbished monitors available directly from Dell (www.dell.com/outlet) or HP (www.hp.com/sbso/buspurchase_
refurbished_computing.html). Refurbished displays are checked and certified by the vendor; however, they do come with shorter warranties (typically 90 days to one year).
Typical warranty coverage for LCD displays is three years for parts, labor, and backlight. From time to time, you'll find a vendor that offers longer coverage. After three years, you can expect to replace the backlight for your display.
When shopping for monitors, don't overlook personal preferences. Like televisions, some monitors will produce pictures that are more pleasing to your eye than others. Some will seem more suitable for your desktop setup. Monitor size preference can be personal as well. For example, I prefer to sit relatively
close to my monitor, so the 30" display that's coveted by many is simply too large for me. My 24" display is just the right size — whether working in a CAD drawing or in a Microsoft Word document with two full pages side by side. I can work with a 19" display if I must, but I find it hampers productivity because of the extra panning and zooming it necessitates.
I am more than happy with my current Dell display, so I'm hoping it lasts a long time. When the time comes to make a change, I'll probably look for the same size panel and the same highly adjustable stand — another personal preference — and perhaps 30-bit color if it is reasonably priced by that time.
Current and Future Trends
Current and emerging trends in LCD displays include DisplayPort connectors, faster sync rates, and variable contrast ranges. New monitors from NEC feature what the company calls X-Light Pro technology, which maintains consistent light output for the useful life of the display and corrects for short-term fluctuations. These new NEC displays also incorporate ColorComp technology to reduce uniformity imperfections by compensating for color and luminance across the screen area.
In the near future, we're likely to see designs that are increasingly thin and energy efficient. We've already begun to see 30-bit color displays on the market, which offer a staggering one billion colors onscreen, compared with the 16.8 million colors possible with typical displays. In addition to more vivid and realistic colors, these displays also create less banding and color reduction artifacts. HP has introduced a notebook with a 30-bit screen.
These displays are likely to become increasingly prevalent as prices drop. Not long ago, a high-end, production-level monitor could sell for as much as $10,000; today, an HP DreamColor LP24808zx 30-bit display is selling for $1,999, down from $3,299 earlier this year.
Caring for Displays
Once you invest in a large LCD display, be sure to calibrate it regularly to ensure it continues to deliver the best possible image quality. The best calibration tool I've found is DisplayMate (www.displaymate.com), which I use for testing all monitors that come through Cadalyst Labs. For 32-bit Windows systems, you can use the USB version and avoid the need to install software.
Cleaning your new LCD monitor is simple and inexpensive. Get a microfiber cloth, such as those used to clean optical equipment, moisten it very slightly with plain or distilled water, and wipe your screen. Never spray liquid directly on the display (it can leak into the housing), and don't use glass cleaner or paper towels (the chemicals in cleaner can etch the display, and paper towels can leave scratches on its surface).
See for Yourself
Although you may enjoy the convenience of shopping online, it's more difficult to determine which models produce a picture that's pleasing to your eye and have a design that fits your desktop. Whenever possible, buy your LCD monitor locally so you can see and test the display and controls for yourself. By viewing a display in person, you also have an opportunity to compare it head-to-head with similar displays that you might be considering.
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