What is commonly used alongside reference tones to calibrate the video signal?

• A. Test Card or Color Bars
• B. Lamps and Cables
• C. Digital Noise
• D. Color Correction Matrix

Answer: (A)

Using a test card or color bars provides a known, objective reference pattern for calibrating video. These patterns display standardized colors, grayscale steps, and alignment marks that let you set and verify brightness, contrast, gamma, and color accuracy across the video chain. When you pair them with reference tones, you can also confirm proper signal levels and synchronization for the entire broadcast path, ensuring consistent video and audio quality.

Lamps and cables don’t offer a standardized visual reference for calibration, digital noise isn’t a recognized calibration signal, and a color correction matrix is used as a processing adjustment rather than a live, reference-based calibration tool.