Choosing a monitor
Computer monitors (external displays for laptops or primary ones for desktops) are still not commodity items. That is (in the opinion of this author), there are real differences in apparent image sharpness as well as features.
This page is meant to give you some ideas of areas to think about, but does not make specific brand recommendations.
Resolution choices (be careful!)
For monitors of any brand and size, there is a sort of "natural resolution". This more or less translates to pixel densities (pixels per inch).
In my view, these are:
| Display size | Pixel dimensions | Description | Aspect Ratio |
|---|---|---|---|
| 24" display | 1920x1080 | "Full HD" (High Definition) | 16:9 |
| 27" display | 2560x1440 | "QHD" (Quad High Definition, 4x 720p) | 16:9 |
| 32" display | 3840x2160 | "4K", i.e., double that of Full HD in both dimensions | 16:9 |
| Other possibilties exist, too: some examples | |||
| 24" display | 1920x1200 | Full HD width but extra height | 16:10 |
| 34" display | 3440x1440 | Ultra Wide QHD | 21:9 |
Take the 27" size as an example: You may see displays advertised which are 27" diagonally, but which are only 1920x1080. So you are taking the pixel count or dimensions of a 24" and spreading (smearing?) them out over a larger display, and making for larger pixels.
Conversely, there are 27" displays which cram a 4K pixel count onto a 27" display, making everything really small.
Right away, large differences like this in resolution for monitors of the same nominal diagonal measurement can explain some of the price differential between selections.
A monitor is not a television
It is worth pointing out the differences between a monitor and a TV. It is a combination of working distance (you sit far closer to a monitor) and how you use it (one uses a monitor to closely examine text or images). TVs often have surprisingly low resolutions: (a "Full HD" display on a 46" TV can still look fine; Even a 4k 65" screen has a low number of pixels per inch but it doesn't matter because you sit far away from it and still cannot see individual pixels.)
How about pixel doubling (such as Apple Retina displays)?
This discussion is distinct from Apple's Retina displays which do pixel doubling, for sub-pixel sharpness (since every pixel is really a 2x2 array of pixels). Thus, the current Apple laptops, say, are 3456x2234 at 254 pixels/inch but only displaying 1728x1117 pixels on-screen. It is rare to see non-Apple external displays that support this sort of pixel doubling.
Furthermore, even if they did, people buy external displays for lots of screen real-estate, and may not want to "sacrifice" that for pixel sharpness. (So, a 4K display in a Retina-type configuration would only give 1920x1080 versus the QHD display that really gives a lot more pixels.)
Panel technology
There are three primary technologies for flat panel displays, being TN (Twisted Nematic), VA (Vertical Alignment), and IPS (In-plane switching). IPS is considered the best of the three because of color rendition/accuracy and evenness of the display when viewing off-axis (that is, it does not get dimmer or distort colors when you are viewing at an angle). This matters more as you get to larger displays.Other considerations
There are other elements which have nothing to do with the actual monitor image but which can make it more of a pleasure to use. Some of these to consider include:
- Will it fit? Will the monitor fit under the standard hutches of NASA-GSFC desks?
- How flexible is the monitor stand?
- Is the stand height adjustable? (Can you adjust the monitor up and down?)
- Can the monitor swivel on the stand (left to right) ?
- How much can the monitor tilt on the stand?
- Can the monitor rotate 90 degrees (to become portrait orientation) ? [This is not a critical feature for many people, but it can be very useful.]
- Is the monitor VESA-compatible? (The square adapter plate on the back for wall or arm mounts)
- How big are the bezels (the (black) area between the edges of the display and the physical edge of the monitor) ? These have been getting smaller over the years. Does this matter to you?
- Extra ports: Does the monitor offer USB or power ports?
- Video connections: HDMI, Display Port, or other?
- Speakers: is there built-in audio? (the quality of these is rarely good)
- Webcam: it is rare to find built-in webcams (so arguably not a make/break buying decision).
- Aspect ratio: do you care about how tall the display is in pixels?
- Does it have a Kensington Security Slot? (Do you feel you need a security cable? (think: bike lock))
- If you're buying this for work, you don't need to pay for "gaming monitor" features, such as certain aspects of the screen refresh rate, etc.
Clearly, no person will care about every feature mentioned above. But you should think about which ones matter to you.
There is an excellent web site with reviews and educational articles about monitors. You can read it here: tftcentral.co.uk.
If you select a monitor that works well for your needs, you could easily use it for a decade or more (they will definitely outlast just about any computer.)
Good luck, and please reach out to our system team if you want specific (brand and model) suggestions.
David Friedlander
October 2022