原装进口，德国爱莎测试卡，杭州奥弦科技。TE264测试卡，是一张对比度10000:1的动态范围卡，

　　其形态是透射式测试卡。对比度10000:1，相当于80dB的动态范围标板。若您想确认，贵公司的摄像机摄像头的

　　亮度解析能力，即动态范围i的宽容度，建议可使用此测试。

　　OECF MEASUREMENT

　　ISO 14524 describes how the densities to manufacture the chart are calculated. The

　　values depend on the desired dynamic range of the chart. In order to measure a camera

　　the contrast of the chart should exceed the dynamic range of the camera under test. This

　　is the reason why typical contrast ranges of today’s targets are 10.000:1 and sometimes

　　even more than 1.000.000:1. Although there are still charts with 12 gray steps and less

　　available, we recommend using at least the TE264 with 20 patches to have enough

　　supporting points for the calculation. The standard version of TE264 uses a screening to

　　form the gray levels. This may lead to increased noise levels or artefacts in the images of

　　high resolution cameras that can resolve the screening. To avoid this problem the chart

　　should fit a limited image height and/or the cameras may, in contrast to the procedure

　　defined in the standard, be slightly defocused. TE264X is available that uses continuous

　　tone film and therefore does not show this problem.

　　An integrating sphere like the LE6 or LE7 provides the best uniformity for the illumination

　　of the OECF targets. Although the targets usually come with density levels and the

　　integrating sphere has a build in illuminancemeter we recommend to use a luminance

　　meter in combination with the charts because the conversion to luminances from densities

　　and illuminances requires a calibration factor. A low cost but accurate device is the

　　Gossen Mavo Monitor.

　　Note: Do not use a teleluminance meter for the measurements!!! These devices are

　　affected by stray light and do not deliver accurate values for the dark patches!!!

　　The opto electronic conversion function (described in ISO 14524) is one of the most

　　important characteristics of a digital camera. It describes how the camera transforms

　　luminance values of an object or illuminance values on the sensor plane into digital code

　　values in the digital image.

　　The OECF is typically measured from a gray scale. Depending on the type of camera

　　different versions of test charts are used. The specification of TE264 D is derived from

　　ISO 14524. It is a test chart with a circular arrangement of the gray levels. These may be

　　affected by lens and camera related shading but since most optical systems are

　　rotationally symmetric they will fall on the same shading level for all patches.

　　原装进口，德国爱莎测试卡，杭州奥弦科技。TE264测试卡，是一张对比度10000:1的动态范围卡，

　　其形态是透射式测试卡。对比度10000:1，相当于80dB的动态范围标板。若您想确认，贵公司的摄像机摄像头的

　　亮度解析能力，即动态范围i的宽容度，建议可使用此测试。