Tuesday, September 11, 2012

Two Nightscape Lenses for the Price of One

The Watchman and the Milky Way, Zion National Park ~ © Royce Bair
The Canon EF 15mm f/2.8 Fisheye lens is one of my favorite night photography lenses because it allows me to include more than twice the sky as my 24mm lens (180º vs. 84º), and because it's really two lenses in one. Let me explain...

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
Although a more complete distortion correction could have been accomplished with software, i.e. DxO Optics Pro, I've found this is not always as aesthetically pleasing as being more selective via Photoshop. I should point out that this lens has fairly acceptable coma at its wide-open aperture of F/2.8; it is about 65% corrected at F/3.5, and it is about 75% corrected at F/4.0.

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.

1 comment:

  1. That's amazing color for light pollution. Gorgeous image.