Introduction to HDTV Dynamic Resolution Test Chart Card

The HDTV dynamic resolution test chart YE0125 is particularly suitable for visually determining the resolution of high-definition cameras. It displays an asymmetrically arranged zone board ranging from 0 to 600c/ph and two zone board segments, with the center located in the left corner. The diamond shaped gap is gray.

The HDTV dynamic resolution test chart displays an asymmetric arrangement of an area board ranging from 0 to 600 cph (cycles per height) and two area board segments, with the center located in the left corner. The diamond shaped gap is gray (D=0.75). The black frame is marked with 100 cph steps. In order to display the complete image of the area board sector that maintains the scaling constant, the test image is wider on the left side than the 16:9 scale. 16: The 9 format is marked by a white arrow, approximately 5.5mm inside the edge.

The HDTV dynamic resolution test chart is particularly suitable for visually determining the resolution of high-definition cameras. It must be considered that monitors also have a decisive impact on modulation transmission. It is very easy to compare several or different cameras on the same display. The total transmission function of the camera, transmission link, and monitor can be measured through scaling.

When testing valve cameras, different anisotropy of the transfer function can be evaluated, i.e., different resolutions depending on the direction of the line grid: not only is the horizontal resolution different from the vertical resolution, but the resolution is usually different in the two diagonal directions. Horizontal resolution is often greatly limited by the low-pass characteristics of the transmission link, especially for noise reduction reasons. Due to the characteristics of electron beam scanning, diagonal resolution is distorted. This does not apply to CCD cameras.

The video signal from the camera output can be used to measure the modulation transfer function. The amplitude of the video signal is determined by an oscilloscope, aiming to illuminate the test image as much as possible. Then, the oscilloscope must accurately trigger the image line, with the vertical part within a linear function of time. In order to better evaluate these measurements, the gamma distortion of the camera must be turned off, i.e. measurements must be taken in linear operation.

The measurement in video signals is not only independent of the transfer function of the monitor, but also provides more detailed quantitative information about the transmission characteristics of the camera compared to the visual determination of resolution limits. This allows for determining the 3dB point of the transfer function, for example. For more accurate theoretical methods, the difference between modulation transfer function (MTF) and contrast transfer function (CTF) must be considered.