Dynamic range
At face value, a measured dynamic range of 10.5EV seems low for the EOS-1D Mark IV, but I didn’t notice any restriction in the range when shooting real-world photographic images. The fairly steep mid-section of the dynamic-range curve indicates good midtone contrast, which helps convey the impression of detail. At the shadow end the curve dips sharply, indicating a compression of the tones in this area.
In keeping with Canon’s other DSLRs, the EOS-1D Mark IV has both Highlight Tone Priority (HTP) and four levels (including off) of shadow-boosting Auto Lighting Optimiser (ALO). As with the EOS 550D and EOS 7D, these options can’t be used simultaneously.
Although it can be difficult to predict the degree of lightening that will be seen when ALO is employed, it can be useful when there are important details that need bringing out in the shadows. When contrast is high it can help photographers produce print-ready images direct from the camera, thus saving time at the computer.
