And out the other side

I had originally lined these images up for a post several weeks back, but that was at the time that Mr Bugg was doing his own monochrome posts and was being snarky, and I wasn’t going to give him any satisfaction in that regard, but now that I just did something about ultra-violet light, I figured I could go to the opposite side of the visible spectrum and do infra-red now.

I had my fun with IR photography in the past, but haven’t done anything recently, and that’s because I had a camera at the time that could do it easily – the Canon Pro 90 IS – but none of my current cameras can tackle it because they all have IR blocking filters over the sensor. Now, I still have the Pro 90 buried away and could presumably use it again, but the last time I tried it refused to power on; this might only have been the battery, I don’t know. All that aside, right now we’re dealing with shots from back in the day, a little after hydrogen had formed I think.

Old Well on UNC Chapel Hill Campus in infra-red
Believe it or else not, this is a full-color image, the barest hint of which can be seen right along the bottom. This is the original frame produced by the Pro 90 and a simple Lee 87P3 IR pass polyester filter; that booginess at the bottom is the edge of the filter, where I’d mounted it to a wire frame for easier handling, getting into the shot. Different filters pass different wavelengths and often produced distinctive color casts, but this one was almost monochromatic. That faint lavender hue served no purpose for me, so I simply converted the image into greyscale anyway, but the dynamic range was also a bit narrow, and the photo begs for more contrast. So a little more editing was in order.

original image showing edits in Curves function
The little graph in there is the histogram within the ‘Curves’ function in most serious photo editing programs, and when you look at the mountain range in that graph, you’ll notice that there aren’t even any foothills over at either side – this means that nothing in the original image actually becomes fully black (left side) or fully white (right.) Can’t have that – we want a full range. So the curve itself is adjusted by moving the corner points, upper right and lower left, inwards until they’re just outside of the mountain. What this does is take the brightest parts of the original frame, somewhere around medium light grey, and bring them all the way up to white, and the same in reverse for the darkest portions. Even though, in the way this is illustrated by the graph, it seems like we’re cutting something off, this was all unused brightness registers, and it works better to think that we’re stretching the brightness of the entire image out to the limits; the brightest part of the image, originally medium light grey, has been boosted to almost-white by doing this, and vice-versa.

Then there’s the curvy bit between those pointers. Instead of a nice diagonal line, I dragged it higher along the right side and lower along the left, which increases contrast within the existing range. If the curve were shaped the opposite way, it would reduce contrast. In this manner, I made the domed structure (this is Old Well on the Chapel Hill Campus of the University of North Carolina) remain stark and bright while brightening the leaves of the trees as well – not as much, because Old Well needs to stand out, but the surreal nature of their brightness needed to be enhanced. At the same time, I darkened down the lower registers, making the branches more distinct against the leaves and also darkening that sky. By the way, this was shot on a bright September day and the sky was brilliant blue – this is just what infra-red does to blue skies and foliage. I now wish that I’d done a frame without the IR filter so you could compare what it looked like in visible light, but it didn’t occur to me at the time (I hadn’t started blogging yet.)

So let’s see the end result in better detail:

Old Well in infra-red, tweaked for improved contrast
With a slight difference in the middle of the curve, I could have made the leaves brighter, but I didn’t want them to appear like snow, and still wanted Old well to dominate the frame, so this is my choice – others may have approached if differently. I’m very pleased with the branches standing out so well, because in visible light they almost entirely blended in with the leaves. This altered image was part of my gallery show at this time last year, as well as being donated to a charity auction many years previously where it sold for more than what I’d valued it as, so at least one other person approved.

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