Maple State Street cultivar (Acer miyabei “Morton”) is Chicagoland’s own creation. A bizarre mix of low twisty branches, primary stems forking out at very low height, making the tree trunk practically vanish at your waist level. Barren exposed wavy roots, make this tree look like someone conducted a cruel experiment with few dozen octopuses by knotting them all together. I think of it as a wax figurine from Madame Tussauds’ struggling under high noon sun, fighting a losing battle.
The tree is as weird looking as it is photogenic.
Enough about the tree, let’s talk light and about how I really struggled with this IR shot. It was too early in the spring with no leaves on any tree when I took it, the morning sun still close to the horizon, so the lighting was very problematic and harsh, even for infrared. And separation of the tree and the background was near nil. In short, tonality was a hot mess.
Which brings me to a subject I’ve been learning about recently and that is infrared and reflectance of non-living objects (such as wood bark). We all know that chlorophyll in foliage is what reflects the most light, so when leaves are around, the math is straight forward and we get those gorgeous radiant and very contrast-heavy IR pictures. In winter, when the main reflective surface in a deciduous forest will be “dead” material, such as tree bark, the problem with contrast significantly worsens. There is no chlorophyll, so the camera has to expose for lower light by setting a slightly longer exposure, resulting in very high contrast between shady areas and areas fully exposed to sun rays. So high, in fact, that you may see highlights and blacks clipping on your histogram before you even touch it in the post. Case in point, you can clearly see white on the trunk above, while the bark in top branches facing away from the sun is nearly black. Very high dynamic range, too high for the camera to handle.
And there comes the problem: post processing. Though I started shooting JPEGs on my GR III, I nearly exclusively shoot RAW on my IR converted GR II. There is simply no way around it. Infrared requires much more work in post than regular visible spectrum photographs. Be it different tonality, unrealistic contrast, channel swapping, monochrome conversion, selective channel split toning, the list goes on. If this shot were a JPEG, I’d be toast. RAW saved it partially, but not fully.
This is a fitting example showcasing where I made a mistake. Usually, in harsh light and extremely high winter contrast I resort to highlight metering by using focus & recompose technique. Unlike GR III, my infrared GR II doesn’t have highlight metering mode, so what I normally do is to set it to spot metering, focus and meter in the center of the picture, lock exposure reading of a bright area, move camera to my desired composition and then take the shot. That way my highlights are perfectly exposed and shadows are very dark, or nearly black.
The thought process behind this is as follows: you can recover shadows, but you cannot ever recover blown out highlights. A well known fact.
This is how it would look in the post:
If I did proportional metering and equally segment-metered for highlights and shadows, the highlights would be nearly white and shadows would not be as dark. In the attempt to save the picture, I’d selectively lower the tonality in highlights in post, making them grey (and very messy), then I’d selectively raise brightness in shadows (though very dark, the camera still did record light information in there we can use), but the picture would be ruined – with blown highlights, there is no information left in the RAW file other than pixels of white, so no software can ever recover what isn’t there.
If I metered for the highlights, I’d have well exposed light parts and very very dark shadows. That could be solved by raising tonality in midtones and shadows – recovering all those pixels, which did record light, albeit very little of it. Still, it should be enough to recover some of the information captured by the sensor.
I can’t recall for sure, but judging by the terrible tonality, I did not follow my own rule and failed to expose for the highlights, then had to scramble in the post and try to recover some of the white clipping. It is apparent on parts of the trunk. This is where Live View and histogram are my best friend. If I don’t keep that bell curve away from the histogram edges, I know I’m in for a bag of hurt.
I have never done it, but this shot gave me an idea of infrared HDR. I could bracket my shots and stack them in post. I am not a proponent of HDR and “larger than life” colors or tonality, so we’ll see. Worth of an experiment.
Back to the tree for a moment: this maple cultivar is reported to do very well in urban locations as a shade tree for parks and streets. I can absolutely see why. The low hanging wavy branches, nearly non-existent trunk and overall looks make it a perfect climbing structure for kids an who would not want to take a picture with a hundred-tentacled wooden octopus!
The root system begs for some close ups.
I’ll be back.