|The Watchman and the Milky Way, Zion National Park ~ © Royce Bair|
Although the heavy barrel distortion from this lens creates a special effect that is liked by many people, I can remove that distortion with software if I choose. The software-corrected image gives me a view somewhat similar to the Canon EF 14mm f/2.8L II USM Ultra-Wide Angle lens, which has a fairly undistorted 114º angle of view (but costs about three times as much as the Canon fisheye).
Here's an example of what I mean. Above, is a shot of The Watchman and the Milky Way, taken from the foothills west of Springdale, Utah at 2:00 in the morning (light pollution from the city is lighting The Watchman). This is the fisheye view without any distortion correction.
In the next image, I left the barrel distortion alone on the left side, but did a partial correction on the right side using Photoshop's "Edit > Transform > Warp" function:
|Same image as above, with partial distortion correction on right side ~ © Royce Bair|
Both of these photos were taken with the 15mm mounted to the Canon EOS 5D Mark III camera body, which produces amazingly low-noise at the high ISO of 6400 (exposure was 30 seconds @ f/3.5).
My favorite Prime Lens for Starry Night Skies: is the Samyang/Rokinon/Bower 24mm f/1.4 because it can be shot wide open, and it produces very little coma aberration (it also costs about one-third of the Canon and Nikon lenses with equivalent specs)!
Royce Bair is the editor of this blog and the photographer of the above images. Here is my gallery of NightScape images. My schedule of workshops, tutorials, and other events is available here.