The Linux System Gamma Calibration article used an NEC CRT AccuSync 70 monitor in the examples. After 8 years of 24/7 usage, it could no longer meet the gamma specification, (a monitor's capability to produce correct gamma deteriorates over time,) and had to be replaced. As a disclosure, I prefer cathode ray tube, (CRT,) monitors, but they do not meet the price point of modern LCD monitors, (particularly on power consumption.) After antagonizing the Google, and finding several candidate monitors, I chose the ViewSonic VA503b, (as a disclosure, I have no affiliation with ViewSonic-the VA503b won the price point at Amazon.) The VA503b is a fairly generic monitor, and I will offer details of the choice of a 15" 1024x768 monitor, below.

Monitor Gamma Calibration

There was some question whether gamma calibration could be accomplished on an LCD monitor because of the "pixel'ation" required by the display, and the dithering the display does to minimize herringbone patterns occurring when thin parallel lines are displayed. Additionally, when viewed off axis, LCDs exhibit errors in colorimetry-and to make matters worse, most LCDs use anti-glare techniques, (to suppress reflection of overhead lighting-a real problem with CRTs,) all of which effect gamma presentation.

The VA503b is quite configurable, but is delivered with a gamma of 2.2, (the industry standard,) and a color of 6500K, (which is industry standard, too.) The newer standard, sRGB is supported, (but supports approximately a gamma of 2.2-it is not done by formula, but by lookup table, and averages a gamma of 2.2, so should not be used for gamma calibration.)

The techniques used in Linux System Gamma Calibration were used to verify that the monitor actually produces a gamma of 2.2:

The same equipment that was used in Linux System Gamma Calibration was used to display the gamma charts on the VA503b, (i.e., same camera, same video card, same graphics system, etc.) Note that the picture has been "pixel'ated" several times-once by the VA503b, a second time by the camera, and, possibly, (if your display is an LCD,) a third time. (Sorry about the tilt-I had two tape measures to the camera, and a drafting protractor to hold constant tilt on the camera at the user's position in front of the display.) Nevertheless, the gamma displayed is close to 2.2. (For repeatability, the buttons at the bottom of the monitor were used to reset the monitor to the factory default specifications, Color Adjust = 6500K followed by Memory Recall to set the factory specification of a gamma of 2.2; xgamma(1) -gamma 1.0 was used for the display in the picture.)

The VA503b does produce a gamma of about 2.2, (I don't know about the stability, or reliability, however-that will take years, hopefully, of monthly calibrations.)

Monitor Selection

There are a lot of demands placed on computer monitors, (probably more so than any other computer peripheral,) because they have to work with many different prevailing standards-not to mention they are directly involved in the human interface. For the task at hand, it will be assumed, that in addition to general computing, (text documents, spreadsheets, email and browsing, etc.,) the monitor will be used to edit photographs, draft drawings, play DVDs, possibly television, and must comply with ergonomic standards. The relevant ergonomic standard is OSHA's Computer Workstations eTool which describes the geometrical relationship between the user and the computer monitor.

Specifically, OSHA's Computer Workstations eTool states that the monitor must be inclined 15 to 20 degrees from the vertical, with the user at least 20 inches away from the monitor. The next requirement will define the size of the monitor-a maximum of 35 degrees side-to-side viewing angle. For a minimum of 20 inches between the monitor and user, this means the monitor screen should be a maximum of 12 inches, which is a 15 inch diagonal screen. Any larger screen would have to be moved away from the user to meet the 35 degree maximum side-to-side viewing angle, (its about 30 inches between the user and the monitor for a 17 inch monitor.) This also means that the viewer's eyes will be in a horizontal plane with the top of the monitor screen, (from trigonometric relationships,) for the 15 inch monitor.

The Society of Motion Picture and Television Engineers (SMPTE) standard EG-18-1994 specifies a minimum of 30 degrees side-to-side viewing angle, (this is for the DVD/television requirement,) so the two specifications overlap by only 5 degrees-but they do overlap, not by much, but enough. Note, also, that this is the "standard" configuration that movie producers and television videographers, (when they are not practicing artistic license,) shoot to; anything shot has to look good within the confines of this geometrical relationship. 30 degrees side-to-side viewing angle is quickly becoming the defacto standard for home theaters, too.

The geometrical relationship between the user an the monitor has now been defined. Resolution of the monitor is a little more difficult because it depends on intended usage. Narrowing down the requirements from commercial camera ready art work, to 35 mm photo, (or digital equivalent,) and noting that commercial photographers can not consistently shoot 50 lines per millimeter, we can calculate the maximum horizontal resolution for the monitor at 50 * 35 = 1750 pixels, (to do better than this, the focus has to measured with a tape measure, and a tripod with remote shutter actuation has to be used to provide the media with sufficient resolution to be displayed on more than 1750 pixels.) Note that this resolution is close to HD television, (1920x1080 pixels for certain DVD specifications, but only 1280x720 is transmitted in the US.) The Video Electronics Standards Association (VESA) 1024x768 standard almost meets the requirement for broadcast television, (the 1280x1024 VESA specification exceeds it,) and VESA 1920x1440 would handle DVDs for the foreseeable future, at maximum resolution.

From my own perspective, 1024x768 is close enough to 1280x720, and most photographic software will display photographs at native resolution, with a slider that moves the screen around the photograph, which is a viable alternative for 2000 pixel horizontal resolution pictures out of a digital camera. Note that a pixel width for a 15 inch diagonal display is 12 / 1024 = 0.0117 inches = 0.3 millimeter, which is the minimum line width required for drafting, (see Drafting Techniques for particulars,) which means the display is adequate for drafting programs, too.

There are some other considerations when comparing computer monitors. Since the display will be used for full motion video, the minimum response time should be a maximum of 1/60 second, or 12 mS, the specifications of the VA503b claim it will do this. The contrast ratio of the VA503b is typical for LCD computer monitors at 500:1, (compared with HDTV at about a thousand, and CRT monitors that are expected to do about ten thousand,) is marginal, but acceptable for an inexpensive monitor.

License

A license is hereby granted to reproduce this software for personal, non-commercial use.

THIS PROGRAM IS PROVIDED "AS IS". THE AUTHOR PROVIDES NO WARRANTIES WHATSOEVER, EXPRESSED OR IMPLIED, INCLUDING WARRANTIES OF MERCHANTABILITY, TITLE, OR FITNESS FOR ANY PARTICULAR PURPOSE. THE AUTHOR DOES NOT WARRANT THAT USE OF THIS PROGRAM DOES NOT INFRINGE THE INTELLECTUAL PROPERTY RIGHTS OF ANY THIRD PARTY IN ANY COUNTRY.

So there.

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