MEGA CYCLE CHART

REFLECTANCE

The test chart is designed for measuring amplitude frequency response of the luminance

channel, i.e. the amplitude of the output signal relative to a reference level as a function

of frequency.

The multiburst frequencies of the chart are: 0.5, 1.0, 1.5, 2.0, 2.5 ,3, 4, 5, 6 MHz. The chart

and equipment shall be arranged as shown in fig.1.

Measuring equipment: Video oscilloscope or preferably video oscilloscope with memory.

The conditions of shooting shall be as follows:

The light density of the transparency version shall be 636cd/m² +/- 5% (2000lx) at peak white.

The correlated color temperature of the light source shall be 3200 K +/- 100 K. The test chart

shall be shot by the camera so that the frame is limited by the arrows exactly coincides with

the edges of the picture displayed on the monitor in underscan mode. The focus control shall

be in auto or manual mode and shall be in best focus. The iris control shall be in auto or

manual mode.

Gain control shall be set to “0 dB”.

Optical filter if any shall be set to “open” position.

The output signal shall be measured by an oscilloscope. The reference level Vref shall be the

level corresponding to the burst 0.5 MHz. The peak-to-peak amplitude Vn of each frequency

burst of the output signal shall be related to the reference level Vref to obtain the amplitude

frequency response A.

A = 20lg (Vn(p-p)) / Vref