Unnecessary Bracketing


Today’s Question: Is there any point in bracketing and blending in HDR [high dynamic range] if the total tonal range can be captured in a single exposure? In other words, if a single image histogram shows no clipping, is there any possible benefit to creating a bracketed HDR version?

Tim’s Quick Answer: There is the potential for reduced noise in shadow areas of the image if you bracket even when no clipping occurs in a single exposure. Thus, if you intend to interpret a photo to reveal significant shadow detail in the darkest areas of a scene, you may see improved results with an HDR image.

More Detail: High dynamic range (HDR) photography is often thought of simply as a way to retain detail in the full range of tonal values in a scene, from the darkest shadows to the brightest highlight areas. An additional benefit of HDR, however, is lower noise levels in the dark shadow areas of a photo. Put simply, blending exposures with HDR photography produces less noise in shadow areas compared to simply brightening up the shadows for a single capture.

Capturing a bracketed sequence of exposures to assemble into an HDR result can reduce the level of noise in the overall image, especially in shadow areas. In addition, extending your bracketing beyond the range of what is absolutely necessary can help reduce noise levels.

Using HDR when it isn’t necessarily critical, or expanding your bracket beyond the bare minimum for shadow detail, can both be helpful for reducing overall noise in the final image. As such, this approach would be most advantageous when you know you’ll want to reveal considerable shadow detail in the final image. If you’ll leave shadow areas relatively dark, that darkness can help hide noise that might otherwise be revealed.