ISF Testing Equipment & Troubleshooting Methods 3

Question 1

What does the PLUGE (Picture Line-Up Generation Equipment) pattern primarily help calibrate?

Accepted Answer

Black level (brightness control)

Answer

The PLUGE pattern contains sub-black, black, and super-black bars that allow precise adjustment of the brightness (black level) control so crushed or elevated blacks are corrected.

Question 2

A waveform monitor showing the luma component of a 0–100 IRE ramp clipped at approximately 90 IRE suggests which problem?

Accepted Answer

Contrast (white level) set too high, causing clipping

Answer

Luma clipping below 100 IRE on a full-range ramp indicates the display or signal chain's contrast/white level control is compressing and clipping highlights.

Question 3

Which type of test pattern is best used to identify spatial uniformity problems like dirty-screen effect (DSE) on an LCD?

Accepted Answer

Near-neutral gray full-field pattern

Answer

A flat near-neutral gray full-field pattern reveals subtle clouding, banding, and dirty-screen non-uniformity that would be masked by content or high-contrast patterns.

Question 4

In a 2-point white-balance calibration, which pair of controls is adjusted?

Accepted Answer

Gain and offset (or lift and gain) for each color channel

Answer

Two-point white-balance calibration adjusts the gain (high-end) and offset/bias (low-end) for each RGB channel to achieve neutral tracking across the grayscale.

Question 5

A calibrator uses a pattern generator outputting limited range (16–235) but the display is set to full range (0–255). What symptom will this produce?

Accepted Answer

Washed-out whites and elevated black level

Answer

When the display expands a limited-range signal intended not to be expanded, black lifts above true black and white never reaches peak luminance, producing a washed, faded appearance.

(ISF) Imaging Science Foundation Certification Practice Test

(ISF) Imaging Science Foundation Certification Practice Test

ISF Testing Equipment & Troubleshooting Methods 3