I don’t often get to an area that the stars aren’t diminished substantially by light pollution, but I was up in Northern Wisconsin recently and wanted to try capturing some star trails. It is really amazing how much the sky moves in just 48 minutes, which is how long this exposure was.
- Canon 5D Mark II Camera
- Canon 17-40mm f/4L IS Lens
- Remote Shutter Release (I use the Canon TC-80N3)
The Set Up:
- Switch the lens to Manual Focus and set focus to infinity. Compose your shot as best you can – it is a little tough when it is so dark.
- I took a few quick trial shots to figure out what manual settings that might work for me. I wanted to keep the ISO pretty low to minimize noise. I settled on f/5.6, ISO 320 and a focal length of 20mm. The picture mode dial on camera was set to “B” for bulb, which lets me keep the shutter open for as long as the shutter button is pressed.
- On my remote shutter release, I pressed and locked the shutter open and went inside, had some dinner and hung out, came back out, released the shutter button and that was that. The exposure ended up being 2,891 seconds (about 48 minutes).
The Post Processing (Using Lightroom 2):
- The one thing I learned from this is that there is a lot of post processing to get the effect I wanted. I’ll go through what I did to get the look you see above, but since there are so many factors that affect the colors (light pollution, air pollution, haze, time of night), there is no one formula that works for everything.
- For the White Balance, the Color Temperature was set to 2833K and Tint was set to -25.
- Exposure was set to -0.38.
- Blacks was increased to 50.
- Clarity was set to +100 (watch out for the “halo” effect that can sometimes appear from too much clarity)
- Vibrance was set to -10
- In the Tone Curve settings, the Point Curve was set to “Strong Contrast”
- I messed with the Hue, Saturation, and Luminance quite a bit. I prefer using the Targeted Adjustment Tool (right) for these adjustments.
- I normally don’t change Hue very often, but I had some mixed light sources affecting the color of the trees, and once I settled on a white balance, the tree at the bottom looked funny. So using the Targeted Adjustment Tool I ended up settling on Green set to -53 and aqua set to -17.
- Saturation was used to help with some of the funny white balance issues in the trees as well. Again, I used the Targeted Adjustment Tool and ended up with the following settings: Yellow -80, Green -48, Aqua -27, Blue -6, and Purple -36.
- For luminance and wanted to turn down the green in the trees slightly, and using the Targeted Adjustment Tool in the sky area, turning it up brought more details out in the stars. The settings ended up as follows: Green -13, Aqua +10, Blue +56, and Purple +6.
- Finally, I cropped photo a little bit. I wanted to leave some of the trees in there, but the original had too much of the trees on the left and the bottom.
- For the blog post, I exported to resize the long edge to 550 pixels, sharpening set to “screen” and “high”. I also wanted you to be able to click on it and see a larger version, so I exported another one with the long edge set to like 1200 pixels and sharpening set to “screen” and “high”. The resized images typically look better if you do the resizing yourself in a program like lightroom rather than letting the web program (blog, facebook, etc.) resize them for you.
- Like I mentioned earlier – a lot of fiddling around to get the look you want, but it turns out pretty nice once you take the time. And lightroom 2 makes it really easy to do.