|Theewaterskloof Dam after Dark - Canon 40D, Tokina 11-16, 20x30sec, f/2.8, ISO 3200
I arrived there late one afternoon a few weeks ago, just in time to catch the last light on some of the trees. I blundered along the swampy shore (it had been raining heavily earlier that week) and tried to reach the trees I had photographed two years ago, but in the gathering dark I eventually gave up and turned back. Next time I'll bring gum boots!
As the last of twilight faded away, the only remaining illumination was the light pollution from Franschhoek and Stellenbosch behind the mountains - and from the Milky Way, which was rising in the East.
I set up my tripod and panoramic head and took a series of 30second exposures at ISO 3200 (the highest my old 40D can manage) and f/2.8, which I eventually stitched into the panorama above. I'll show you my post-processing below. It's quite similar to how I made the Quiver Trees by Night series.
|Last Light - Canon 40D, Canon 70-200 f/4 IS, 130sec, f/11, ISO 100, ND filter
Composing a panorama is difficult, since it is very hard to visualize what a 270 degree view will look like compressed on a single page - that is simply alien to the way we normally see the world, which is why ultra wide-angle panoramas can be so striking. There are a few tricks worth knowing, though.
First, parallel lines in the sky get turned into arch-shaped structures in the final panorama (assuming a equirectangular projection or similar). Such patterns may by quite subtle, often just a statistical asymmetry in the random pattern made by clouds - the linear structures aligning parallel, or sometime perpendicular, to the direction of the wind. But in a panorama, these arches can become quite obvious, as in the image at the top of the post. The lines in the clouds here were parallel to the shore of the lake (that's just dumb luck on my part), and so the feet of the main arch stand nicely above the edges of the water.
I set up my camera at the point on the shore nearest to the stumps, so that way the stumps would end up in the center of the distorted image of the lake, and thus also directly beneath the arch in the sky. On my way there I had hoped that the Milky Way might arch over the whole scene, but it was still early and the Central Bulge was just rising in the East. I was again lucky in that it is nicely balanced by the brightest region of light pollution in the West.
Once again, this shows that light pollution - hated by most astrophotographers - can contribute something essential to the composition.
I didn't do any. I just found myself with a free evening, packed my gear into the car and drove off. I was mostly lucky to get this shot. I really should have done my homework, though, and with wonderful free software like Stellarium it is child's play to predict exactly where the stars and moon will be at any time and location.
I always shoot RAW (for maximum flexibility), and import the images into Lightroom. I had made 20 exposures, covering almost the entire sky. I had learned from previous experience: rather include too much than too little, you will crop a lot anyway.
|The 20 exposures in Lightroom
I made some basic adjustments in Lightroom: Pulled down the highlights (the highlights actually clipped in the brightest part of the cloud on the right - I should have been more careful), raised the shadows, and set a very low color temperature white balance to better contrast the orange light pollution from the blue stars.
I then exported the images as 16-bit TIFF files (so as to keep all color information for Photoshop to work with).
Next, I loaded the files into Hugin, my favorite (though quirky) panorama stitcher. Hugin does a very good job at finding control points (pairs of points in separate exposures that should coincide in the final panorama), especially in starry skies. But since I had such high noise levels in my exposures (ISO 3200 with shadows additionally lightened), Hugin's built-in control point finder struggled a bit with the darker regions. It's also quite bad when control points are added in the clouds, since these move from shot to shot - especially during a 30 second exposure. So I spent some time adding control points mannually.
Once Hugin had finished stitching a nice 16-bit high resolution panorama, it was ready for Photoshop.
|Adjustment layers in Photoshop
These are the adjustment layers I made. As you can see, my weapon of choice is the Curves Adjustment, masked so as to affect only certain portions of the image. Curves gives you the finest possible control over contrast, and I also use it for lightening and darkening, instead of the dodge and burn tools.
|Tone curve for tree stumps
|Darken the clouds
|Increasing contrast in the Milky Way
|Darkening edges and corners
One layer I had better explain is the "faked texture for blown bit". This is a transparent image layer onto which I cloned a bit of texture onto the blown bit of cloud from the surrounding cloud. I just selected as source the bottom layer and then painted onto the transparent layer with the clone stamp. This way I could control the opacity of the layer and thereby adjust just how much fake texture to introduce. I tried not to overdo it. Here are the before and after pictures of that portion of the image.
Some more pics
Well, that's it. Here are a few more images of the Theewaterskloof Dam (taken during a full moon outing with the Helderberg Photographic Society), as an apology for neglecting this blog for so long. My excuse: I'm holding my inaugural lecture on Thursday, and that takes a lot of preparation. Enjoy!
|I really need to lay off the colors in my HDRs...