Night Focusing the Rokinon 14mm Lens

MilkyWay over String Lake, taken with the Rokinon 14mm lens ~ © Royce Bair

Many have purchased the Rokinon 14mm f/2.8 lens for starry night photography, at my recommendation, and then have written to me about their difficultly in focusing this lens for night photography.

Focus Frustrations and Fix: I must admit, that the first time I tried to focus this manual lens I was a bit bewildered. It seemed to stay in focus no matter what I did! This is due to the incredible depth of field of this 114º angle lens, even wide open. After considerable tests in the daylight and field testing at night, I can make the following recommendations: Don't focus on the infinity mark (some are even confused as to what position the infinity mark is located on the lens barrel).

Left: This is NOT the infinity position. Right: This is the infinity position.
HOWEVER, I recommend the following focus position below:

This is the focus position I recommend when shooting 'NightScapes':
Shoot at f/2.8, and set your focus halfway between the 10-feet mark and the infinity mark.

Hyperfocal Distance correction: Some hyperfocal charts will recommend focusing on 7-feet (actually, 7.62 feet—saying that everything from 3.81 feet to infinity will now be in focus). I find that I get better infinity sharpness at my focus position, and I still get good depth of field in to about 10 feet. I think this is because most hyperfocal DOF charts are based on the sharpness quality of an 8x10 inch print, whereas I want 16x20 and even 30x40 quality. (Quoting the Cambridge in Colour website about hyperfocal distances: "... it's often helpful to use a more rigorous requirement for 'acceptably sharp,' or to focus slightly further and improve background sharpness.")

Best Ultra-Wide Lenses for Starry Night Photography: The Rokinon 14mm f/2.8 lens has incredible coma correction and quality for a lens of it's price (about $350). It surpasses the coma aberration correction (even wide open) of most lenses in its ultra wide-angle category. I find it has about 1.5 stops of light fall-off in the corners (vignetting), which is easily corrected in the Adobe Raw Converter (via Photoshop or Lightroom). It is also a little soft in the edges, unless you stop down to about f5.6 or smaller; however, I don't recommend doing that if you're using the lens for high-ISO night photography—just keep this lens wide open, and place important areas away from the edges or corners of your composition. When doing daylight landscape photography, I found this lens performed optimally at f/11, with the focus set at 7-feet (f/16 was also very good, but at f/22, I began to notice a little bit of diffraction).  If you're a Nikon user (and can afford to shell out about $2,000), the only other lens I'd recommend in this category is the Nikkor 14-24mm f/2.8 lens. This lens is well-corrected in every area, and is sharper than most prime lenses. It is a little sharper than the Rokinon, especially in the corners. Some Canon users like it so much, they even have the Nikon mount adapted to fit their EOS bodies!

Full-resolution crop of the top photo. Enlarge or download this image to see for yourself the quality of the
Rokinon 14mm when used wide open at f/2.8—just keep in mind that you're also seeing the coarseness of an
ISO 6400 image that has had some noise reduction in the ARC software (which tends to soften shadow detail).