Dynamic Photo HDR

30 Dynamic Photo HDR

If you use the Quick Preview or go to the Advanced Options you will see that in these extreme areas

there is a noise on the Preview HDR image.

The merging function has simply not enough range to produce the HDR image. In these extreme

values there is so little data that even smallest change in the range will produce unwanted jump in the

dynamic values resulting in this noise.

To fix this we can use Custom Weighting function to clip the extremely overexposed bytes.

First we will start with a bell shape curve:

This may even more pronounce the noise than any of the default setting, but that is just fine for now.

We will create a point near the right side of the curve (in Overexposed part) and move it down so it will

cut to the horizon a bit earlier.

This will clip out the still over-exposed bytes during merging the final HDR image.

The result HDR image has no noise now. (It is still over-exposed however, but we cannot fix this

unless we are able to re-shoot the image with -3 or -4 EV)