I’m looking for and would sincerely appreciate your recommendations for the best prime EF-mount ultra wide-angle lens for use on Canon EOS crop-sensor (7D) and full-frame cameras (specifically 6D, and 6D Mk. II) for astrophotography.
(While there are excellent zoom lenses available, the possible risk of chromatic aberration makes them impractical. That said, I’m a relative novice to astrophotography and still have a great deal to learn — so if you use a zoom lense for astrophotography, please let me know of your experience.)
I’m imaging asterisms and the Milky Way which require relatively longer exposures but I wish to avoid having stars appear oblong in shape from too-long an exposure; to that end, I need the fastest glass possible to obtain as much detail a lens is capable of capturing — as well as the quality of the detail that is captured. Canon’s 14mm f/2.8L is a good lens, but is it the best quality glass (assuming that cost is not a factor) on the market? It must be heresy to ask if other manufacturers produce a better lens, but I’m willing to consider all contenders as long as the lens is compatible with my Canon cameras: price is not a consideration.
As I disable autofocus and image stabilization in taking these types of photos, a manual focus (only) lens such as those made by Zeiss is perfectly acceptable.
I’m well aware that below f/2.8, price increases dramatically: while having an equatorial mount would allow for longer exposure times without star distortion, it would create problems for foreground terrain blurring and additional post-production labor, which I’d like to avoid if possible. My 6D is heavily modified for heat reduction and has had its IR filter removed so that light in wavelengths of 656.28 nm appear in photos, but the scale of these structures make use of a telescope impractical. Light pollution poses another difficulty with increased exposure times, so high-quality fast glass is a better option for my purposes.
Any lens f/2.0 or below, in the range of 8-18mm, might be ideal. I would appreciate anyone with experience with this lens type sharing their recommendation.
Chris P. Bacon
F-1; AE-1; EOS 1V, EOS-1D X Mark III, 5D Mk IV, 6D, 6D Mk II, 7D, and 7D Mk II; scads of Canon, Zeiss, and Sigma lenses.
