Tuesday, August 04, 2015

The Darkside of AUTO HDR

I have been in the habit of taking bracketed exposure sets for a long time. Not so much that I want to do a formal HDR but really just as a safeguard against getting and exposure wrong. Particularly when I’m not confident the light meter is giving me the right exposure, the exposure I want rather than an average grey. In some case I can use one of the exposures only, or perhaps I can make a composite from two or all three of the images or I can use the various HDR techniques to gain a broader dynamic range.

Troubles can surface if all the decisions are passed onto an automatic process. This can be appealing because you can save time. It also removes your input into the creativity or aesthetic decisions. However more and more systems are offering HDR and it is now so often a one click solution.
Bald Hill windfarm makes itself noticed
This example might make the look like Tony Abbot’s comment about blots on the landscape could have a glimmer of truth. The reality is this image is the google+ autoawesome HDR has over adjusted the sky and produced the telltale halos of inappropriate tone mapping of high contrast areas and dirty skies. There are techniques to fix these halos but the best solution is to avoid them in the first place and don’t rely of automatic processes to get it right.
Postscript: A small upside is it has highlighted that I have a couple of dust particles on my sensor, and time for a clean

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