HDR vs. SDR - Exposure Considerations


HDR vs. SDR - Exposure Considerations

Exposure in a camera for HDR and SDR can basically be done in a similar way. Regardless of SDR and HDR shooting, exposure should be done correctly in mid-tone areas. For bright areas, however, things are different, and here the approaches already differ significantly. Thus, the brightness upper limit of HDR can very quickly appear "unnatural" or "disturbing". Therefore, it is important to reduce the upper brightness limits for shots that are planned for HDR in order to be able to better compensate for and edit, i.e. adjust, the brightness differences in the workflow afterwards.

Contrary to the assumption that you actually need to pay less attention to brightness caps in HDR because a larger luminance range is "available", exactly the opposite is the case.

Brightness ceilings should not exceed certain values in an HDR production and certain brightness values have to be set at certain levels, it is advisable to keep an eye on the brightness ceilings in HDR productions during the recording and to compensate accordingly, for example, if they "run out". For example, reducing the ISO value and, of course, ND filters in many cine cameras can help to compensate for the upper brightness limits. But what do you do with the image in the mid-range? And how do you deal with noise? Basically, you should overexpose even with HDR shots; there is hardly any difference between SDR and HDR productions. However, in HDR productions you should pay attention to the upper brightness limits and certain contrast differences in order to make the shot look natural in the end.

In the end, this means nothing other than that the balance has to be right in terms of brightness. For example, if a person is standing in front of a window, in HDR production it can quickly happen that the person is over-illuminated by the high luminance of the window. In an SDR production, clipping is often accepted, but in HDR productions clipping is taboo. Ergo, HDR productions require more attention and better handling of the illumination of a scene from the start, if you are aiming for high image quality in the final product.

In our HDR courses, we show what you absolutely have to pay attention to in an HDR workflow, and in our "Hands On Set" workshop, we go into the specifics for shooting HDR productions.

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