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Commercial Spectrum Readings

10638 Views 20 Replies 2 Participants Last post by  chriscmore
All readings performed with a X-Rite certified and calibrated i1pro spectrophotmeter. This spectrophotometer is calibrated yearly by X-Rite.

X-Rite i1Pro Device Specifications

  • Spectral measurement device,supported measurement modes:
    Reflectance single measurement
    Reflectance scanning measurement with automatic patch detection
    Emission: radiance measurement (monitor measurement)
    Emission: irradiance measurement (light measurement)
  • Spectral analyser: Holographic diffraction grating with 128 pixel diode array
  • Optical resolution:10nm
  • Physical sampling interval: 3.5nm
  • Spectral data: Range: 380 to 730 nm in 10nm steps
  • Measurement aperture: 4.5mm diameter
  • Measurement geometry: 45°/0° ring illumination optics, DIN 5033
  • Light source: Gas filled tungsten (Type A)
  • Physical filters: No or UV cut (Filters not exchangeable)
  • Inter-instrument agreement: Average dE*94 0.4, max. dE*94 1.0
    (Deviation from X-Rite manufacturing standard at 23°C for single measurement mode on 12 BCRA tiles, D50, 2°)
  • Short-term repeatability: ΔE*94 <= 0.1 (D50, 2°), with respect to the mean CIELab value of 10 measurements every 3 seconds on white
  • Data format: Spectral radiance (mW/nm/m2 /sr); Luminance Y (cd/m2)
  • Measurement range: 0.2 to 300 cd/m2
  • Short-term repeatability: x,y: +/- 0.002 typical (CRT 5000°K, 80 cd/m2)
  • Type: Cosine-corrected diffuse light measurement head
  • Diameter: 6.0 mm
  • Data format: Spectral irradiance (mw/nm/m2), Illuminance Y (lux)
  • Physical dimensions: 6”L x 2.6”W x 2.6”H (151 x 66 x 67mm)
  • Weight: 6.5 oz (185g)
  • Power conditions: Device powered by USB. No additional charger or battery required. USB 1.1 high power device.

This will be a closed thread with all of the spectrophotometer readings of all the commercial materials I have.

This is what the chart will look like. This is a reading from a X-Rite N5 Gray Card.

The upper left side has all the data fields. The middle left is the D65 bullseye. The lower left is the RGB Color Balance which shows the saturation for each primary color.

The upper right side is the spectrum chart. Below that is the CIE plot and the Color Temp gauge.

The Y value in xyY is a foot lambert measure, not the standard cd/m2 measure we are used to seeing. Multiply it by 3.4262590996353834259536468581083 to get the proper nits value.
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Re: Data and Testing Definitions and Intro

I spent some time with the new Sencore and have some results of the Center Stage XD color testing like I mentioned I'd try to get around and do.

Our Sencore OTC-1000 was calibrated at their facility against a Photo Research PR650 Spectra Colormeter (ID#73P650-1, SN 60940101). An Epson 7500UB that Epson sent us was calibrated to D65, x=.313 y=.329 on the 1931 CIE chart using a white reflectance standard target from NASA.

First, the Epson 7500UB was calibrated to the NASA reflectance target. Then, the target was replaced with the Center Stage XD screen material to measure what difference in color it had to the calibrated reference. The measured result shows a color value of x=.315, y=.333 or a color shift of x=+.002, y=+.004, dE=2.5. The resulting color temperature was 6345K. Delta RGB measured red +/-0.0%, green +/-0.0% and blue -2.9%.

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