高動態范圍（HDR）測試卡的密度范圍超過120dB（光密度>0.6）。該測試卡可以測量相機單個圖像色調響應、噪聲和HDR相機單個圖像而不是多個圖像的動態范圍以及包圍圖像的曝光。ITHDR36的斜邊緣與MTF測量比例為4:1。邊緣具有一個MTF50≥16周期/毫米，這是比好噴墨圖卡還要好約3倍。中間的灰色背景密度非常類似于36補丁動態范圍卡，實現與自動曝光相機的正確曝光。HDR的黑色背景測試目標相機自動曝光模式傾向于使感光過度明亮的補丁。

Details

The High Dynamic Range (HDR) test chart has a density range exceeding 120dB (optical density >6.0). This chart allows you to measure the tonal response, noise, and dynamic range of HDR cameras with a single image instead of multiple, exposure bracketed images. The ITHDR36 contains slanted edges with 4:1 contrast for measuring MTF. The edges have an MTF50 >= 16 cycles/mm, which is about 3 times better than the best inkjet charts. The middle gray background density closely resembles our 36-patch Dynamic Range target, enabling proper exposure with automatic exposure cameras. HDR test targets with black backgrounds tend to overexpose the brighter patches with auto-exposure cameras.

The HDR chart’s active area of 197 x 235mm is a good fit for both the DNP Standard Color Viewer and ITI LED lightbox. Imatest recommends using the HDR Target with a high illuminance light source (close to 10,000 Lux) in order to provide sufficient light to test image sensors over their range of sensitivity. The chart is well suited for measuring both camera and sensor dynamic range, which are fundamentally different. Camera DR measurements are affected by flare (stray) light in the lens. They represent real-world performance. Sensor measurements are based on the patch pixel and noise levels in unprocessed RAW images, using the technique described in Multicharts/Multitest/eSFR ISO Noise, which fits data to an equation based on dark and photon noise.

The Imatest 36-patch High Dynamic Range Target includes an acrylic frame which can be excluded.