Originally Posted by BattleAxeVR
I'm also looking for an affordable meter for some of my own prototypes, do you know if the i1Display Pro will work for narrow bandwidth RGB laser projectors? Or anything that will?
I find sites that don't mention their list prices kind of suspicious, when it makes you contact them first. So I'm skeptical the price is going to be cheaper than the more well-known brands and an actual response to the OP's under 300$ price query, but it's still worth my time to jump through these hoops if it saves me a few hundred on software afterward.
i1Display PRO is an amazing meter for it's money (for the price range you are searching, below $300), but as any colorimeter, it's performance good when it will measure a display/projector SPD which will be close to the tables is coming from the factory.
A tristimulus colorimeter uses filters to separate light out into color components, and then fits those to matching curves based on the human eye, to produce color values in one or another three-value color space (XYZ, xyY, etc.) based on what the human eye would see.
The goal of any tristimulus colorimeter is to measure a display with responses matching the three CIE color-matching functions. In order to do this the colorimeter typically employs some form of filter/detector combination.
Filtering detector response to match the CIE color-matching functions is difficult. In fact, most commercial tristimulus colorimeters, have significant detector/filter errors.
Measurement results can be reasonably accurate when the colors are broadband because colorimeters are typically calibrated against NIST (National Institute of Standards and Technology) traceable and spectrally broadband CIE Illuminant A source of light having a correlated color temperature (CCT) of 2856 K to represent typical, domestic, tungsten-filament lighting. Some colorimeters are being calibrated against a reference state-of-the-art grade one LCD monitor.
Because the three primary colors (red, green, blue) that comprise the color gamut of LCD, LED or OLED displays are usually other than broadband; deviations from the desired color-matching-function responsivities can occur that will result in significant errors in color and luminance measurements whenever the spectra of the colors are no longer broadband; when measuring the primary colors of a display, or any mix of them.
Due to imperfect spectral matching of the three channels to the color matching functions (CMF) measurement errors occur, which rise with increasing spectral difference between calibration source and test source.
For that reason, i1Display PRO is coming with additional (from default Generic CMF) spectral corrections for each display technology (CCFL, Wide Gamut CCFL, White LED, RGB LED, OLED, Plasma, RG Phosphor, Projection) because different display technology can have very different spectral power distributions; these additional tables helps to reduce the chromaticity/luminance errors.
i1Display PRO colorimeter initially designed mainly as the ideal tool for web-designer/photographer and post-production market; while it became very popular to the consumer TV/Projector market also; so the models of the displays used from X-Rite to measure and create each display technology spectral characterization correction (at 1 nm internals using a Konica-Minolta CS-1000 spectroradiometer) was selected from a list of popular displays from these markets.
For example, X-Rite used a Sony PVM-2541 RGB OLED Monitor to create the OLED spectral correction for i1Display PRO which can be useful when you will measure the Sony or FSI (Flanders Scientific Inc.) RGB OLED Broadcasting Monitors and not a consumer LG WRGB OLED or the following brands which are using LG's WRGB OLED panel also: Sony, Panasonic, Toshiba, Loewe, Philips, Skyworth, Metz, Grundig, Vestel, Arçelik and Bang & Olufsen.
For RG Phosphor they used the Dell Ultrasharp U2413 and AU Optronics B156HW01 Monitors, not a popular Vizio RG Phosphor consumer display.
For LCD-CCFL IPS (EIZO/HP LP2465), for Wide Gamut LCD-CCFL (NEC 241/271/PA271W), for Projection (Marantz/HP/Panasonic), for CCFL-LED IPS (Eizo/HP), for RGB-LED (HP/SOYO) and for White-LED IPS (LG/Samsung SyncMaster/AU Optronics B156HW01).
The only exception was for Plasma where they used a consumer Panasonic Plasma TV.
The best choice to achieve the most color accurate results by measuring any display/projector technology will require to have both a spectrophotometer/spectroradiometer and a colorimeter.
Meter profiling is a process for improving the accuracy of a filter-based colorimeter, for a specific display/projector. Profiling creates a calibration profile for the colorimeter, for the display currently being measured, based on display measurement data from a reference spectrophotometer/spectroradiometer.
When you profile a colorimeter, you measure the unique spectral characteristics of a display with a spectrophotometer/spectroradiometer and basically you transfer that accuracy to your colorimeter, for that display/projector.
The process is known as the Four-Color Matrix Method (FCMM) for Correction of Tristimulus Colorimeter developed by Ohno and Hardis at NIST (National Institute of Standards and Technology).
When you have a such ultra narrow SPD of Blue Laser projector (or RGB laser), profiling your colorimeter (any brand/model) using an i1PRO1/2, you will see an improvement, but errors can be reduced more when you use a 5nm Spectroradiometer.
For example see below some SPD graphs coming from different blue laser projectors (see peak shape but weighting also):
The spike of blue of laser is ultra narrow to be characterized properly by the coarser read bandwidth of the i1PRO2 because it does not have enough spectral resolutions (i1PRO2 has 128 sensors binned into 41 10nm increments).
A higher resolution (2 - 2.5nm) spectroradiometer can increase more the accuracy but it's required when you will measure an RGB laser source, with Blue laser with 5nm is enough.
But with 5nm spectro with RGB laser source you will see significant difference over 10nm (i1PRO).
For that reason the best idea is to get a colorimeter for you (i1Display PRO) and then see if you can rent a high-end spectro or hire a pro (for meter profiling only service) with a 5nm spectro, like JETI/PhotoResearch/Colorimetry Research/Minolta...a 5mn spectro or lower which is required for such narrow band light sources, you will able to do create a more accurate meter profiling for your i1Display PRO.
For more details about i1Display PRO or i1PRO2 and generally how stuff works, about meter profiling, certification of meters or other details, you can see them all collected there: http://www.displaycalibrations.com/x...ions_info.html
JETI has available in interesting PDF to take a look, talking for measurements of RGB laser projectors: JETI - Selected problems of display and projection color measurement