Thursday, March 02, 2017

HDR on the forest floor

HDR on the Forest floor

I visited the Tahune Air Walk and forest on a largely bright (summer) sunny day, but rainforests are typically dark (shaded) places on the forest floor. Shouldn’t a sunny day be a better time to photograph?

The answer is NO! The dynamic range of light (the range in strength of illumination, from darkest to brightest) on a sunny day is significantly higher on the sunny day, The bright splashes of foliage where shafts of full sun light is reflected many times brighter than the nearby glom of full shadow, yet there is detail there also. Whilst our eyes can handle this situation a camera and the dynamic range it can capture will probably be a lot less than required.  Typically you will your photo will have correctly exposed (or maybe slightly overexposed foliage behind dark silhouettes of tree truck of overhanging vegetation. On an over cast day this difference is much narrower, and you are much more likely to get a decent picture.

imageSo it seemed logical that this is a perfect opportunity for getting better images with a set of bracketed images (using EV steps, see screen capture on the right) and HDR post processing these images. Here I am using lightroom and the NIK software add in which has worked fine. The resulting HDR image does manage to get the shadow detail and preserve (not over expose) the colour of the foliage. I is much closer to what I remember seeing (and feeling). There is a lot that can be done at the post processing stage and this is usually referred to a tone mapping, how the extra illumination and colour detail is mapped back into the colour image and this is where HDR can get its bad name because you you can push the colour, local contrast and other aspects into very surreal and painterly abstractness. I am becoming a fan of NIK HDR Efex and their realistic presets (either balanced of deep) because they stay closed to my expectations.

I have returned to using lightroom to mamage photos on my HP Spectre and definite use two organization tools, Colour (eg. I flag bracketedimage sets with yellow) and then I stack the original images together. Thus reducing the clutter or many images that are the same.

I also have gone one step further in this image and used OnOne 10’s enhance and magic eraser to reduced the impact of a dead fern frond in the upper right and also detail filter to reduce overall digital noise, but keep as much detail as possible.

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