High dynamic range

High dynamic range (HDR) is used to refer to photographs which have captured a broader range of luminosity values than what is usual. In most contexts it implies a higher dynamic range than a digital camera sensor can detect between saturation and its noise floor. How can this be achieved? By combining several images so that different parts of the scene come for images taken with different exposure settings. In other words exposure bracketing followed by digital processing to merge the images. If you do not know what is the meaning of bracketing in photography please first read my earlier post on the subject. Continue reading High dynamic range

Bracketing

[post revised on 2017-10-21]

Definition and explanation

Before describing different types of “image merging” workflows, I will explain some terms that I will be using in this blog. Today I will explain the meaning of bracketing.

Bracketing consists in acquiring a series of images with different camera settings. The word bracketing comes from the idea that we have a target value for the setting, say exposure, and we acquire images with this exact target setting and settings both at slightly large and slightly smaller values (bracketing both “sides” of the target). At least three images need to be acquired for the meaning to strictly apply, but in some exceptional cases even hundreds images are acquired. Continue reading Bracketing