Saturday, February 21, 2015

Macro to the rescue

Today was not the best for outdoor photography, being rather dull and cloudy. Nevertheless I wanted to do something. So, as I was getting in some wood for the fire, I found my subject: a desiccated a Darkling Beetle, a member of the Tenebrionidae family...but don’t ask me what one!

Of course the subject selected the lens for me: my trusty EF 100mm F2.8L macro lens and I decided to ‘just’ see if I could use natural window light, as the dull sky created a rather large soft box.

As for a background, I remembered we purchased Romanesco broccoli, which is also known as Romanesque cauliflower. Wiki tells us that the Romanesco superficially resembles a cauliflower, hence its other name, but it is light green in colour, and its form is rather fractal like. The inflorescence (the bud) is self-similar in character, with the branched meristems making up a logarithmic spiral. In this sense the bud's form approximates a natural fractal; each bud is composed of a series of smaller buds, all arranged in yet another logarithmic spiral. This self-similar pattern continues at several smaller levels. The pattern is only an approximate fractal since the pattern eventually terminates when the feature size becomes sufficiently small. The number of spirals on the head of Romanesco broccoli is a Fibonacci number.

Anyone looking out for unusual macro settings would be well advised to get down to their local food store and look at the exotic food that is readily available these days: we got ours from Whole Foods.

The beetle, of course, being dead, was a rather willing subject; so posing was simple! As for camera settings, I decided not to focus stack: I will try that on another occasion, together with my ring flash.

Being a macro lens, the depth of field was only a millimetre or so, hence I was expecting a fall off across the depth of the image. I manually focused, using a 10x zoom window, and used Magic Lantern’s dual-ISO, ie a single image, ISO-bracketed shot, with alternating Bayer line pairs at ISOs of 100 and 800. Finally I pushed the aperture to F/20, which placed it in the degraded diffraction area, ie beyond F/16, but I needed help with the depth of field.

After exporting the images into Lightroom, I first delaced the dual-ISO, which gave me my starting DNG negative. I then used a little LR ‘trick’, after carrying out the lens correction.

The trick, which is useful for dark images, is to go to Camera Calibration and select the 2010 Process. Then go to the Basic Panel and, low and behold, there is the ‘old’ Fill Light slider. After I had adjusted the Exposure and applied some Fill Light, I then ‘burned in’ the 2010 Process settings by exporting to another application, eg one of the Nik plugins, BUT without changing anything. This gave me 16-bit TIFF which I then adjusted further with the 2012 Process sliders.

A final tweak was achieved after exporting the image to Photoshop and using one of favourite plug-ins to enhance and boost local and global contrast, namely Fixel Contrastica 2 (http://aescripts.com/fixel-contrastica/)



Although these two images need more work, eg I will try focus stacking next and look for another ‘subject’ around the house, I think the combination of the beetle and the Romanesco broccoli provide a rather interesting image. As usual I welcome feedback on this any of my posts.

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