Testing Equipment & Troubleshooting Methods Flashcards

Which instrument measures the color temperature of ambient light in a viewing environment?

Answer: Spectroradiometer

A spectroradiometer measures the spectral power distribution of light sources, allowing accurate color temperature readings of ambient room lighting.

When using a test pattern to check white-balance tracking, what does it mean if the grayscale steps all shift toward blue at higher IRE levels?

Answer: The blue gain is set too high

A blue shift in upper grayscale steps indicates blue gain is elevated, pushing white-balance off neutral at high luminance levels.

A DisplayCAL profiling run reports an average delta-E of 4.2 after calibration. Which action should the calibrator take first?

Answer: Check whether the colorimeter has the correct display correction matrix applied

An unexpectedly high post-calibration delta-E often results from using a colorimeter without the proper display-type correction profile, leading to systematic measurement errors.

What is the primary purpose of a lens aperture test chart used in camera setup?

Answer: To evaluate sharpness and resolving power at different f-stops

Lens aperture test charts (such as Siemens stars or resolution wedges) reveal how resolving power and aberrations change across the lens aperture range.

During a projector calibration, luminance measured at the center of the screen is 14 ft-L but drops to 8 ft-L at the corners. What does this indicate?

Answer: Lens edge falloff or vignetting

Center-to-corner luminance drop is characteristic of lens vignetting or optical falloff, a property of the projection optics rather than gamma or color settings.

Which test signal is most useful for detecting chroma noise in a video display or signal chain?

Answer: Color bars

Color bars generate saturated, defined chroma signals that make chroma noise, cross-color artifacts, and bandwidth limiting immediately visible.

An ISF calibrator notices the display measures correct color points at 75% stimulus but the primaries drift at 100% stimulus. Which display parameter most likely needs adjustment?

Answer: Color management system gain at peak stimulus

Drift of primaries at 100% stimulus is a gain-related error in the color management system, requiring adjustment of the CMS gain values at peak drive levels.