Lenses – The Amazing Sky

December 15, 2024December 16, 2024

The Great Auroras of 2024

The Sun peaked at “solar maximum” and gave us wonderful sky shows in 2024.

Officially, the Sun reached the peak of its roughly 11-year cycle of activity — “solar max” — in late 2024. That’s according to NASA and NOAA.

During 2024 several major solar storms erupted as a result of the Sun’s increased activity. They blew massive clouds of energetic particles — electrons and protons — away from the Sun. Some of those storm clouds swept past Earth, sparking bright auroras widely seen in both the Northern and Southern Hemispheres.

The rise and fall of solar activity. The peak at right is as of November 2024 in mid-Cycle 25. Courtesy SolarCycleScience.com.

I was fortunate enough, as many were, to witness several of 2024’s great auroras, from home in Alberta, and from as far south as Arizona.

Trips north to Churchill, Manitoba, and to northern Norway also presented some fine aurora nights. But that’s normal at any time in the solar cycle from those sub-Arctic and Arctic locations.

It’s when the aurora comes to you that you get a truly memorable show. And 2024 had its share of them.

NOTE: My blog has a lot of images and links to movies that may take a while to load. Images can be clicked on to bring them up full screen. The blog also contains many links to other sites to learn more!

Starting the Year — February in Churchill

This was the month I made my annual trek to Churchill, Manitoba, to instruct aurora tour groups at the Churchill Northern Studies Centre. Why not join us in 2025?

An aurora selfie at the Churchill Northern Studies Centre, on February 10, with a modest Kp4-level storm underway. This is 20-seconds with the TTArtisan 11mm fisheye lens at f/2.8 on the Canon R6 at ISO 1600.

Yes, the air is cold (usually about -25° C) but the skies are often clear and aurora filled, as Churchill sits under the normal location of the auroral oval, the main zone of auroras. In fact, it is as far south in the world as the auroral oval normally resides, at a latitude of only 58º North, well south of the Arctic. If it’s clear, there’s almost always some level of Northern Lights.

This year, 2024, was no exception. Even on nights with low readings on the usual auroral indicators we got sky-filling displays that are rare down south.

This is a southerly arc of green and red Northern Lights on February 9. This is a panorama of 5 segments, each 20 seconds with the Laowa 15mm lens at f/2 on the Canon R6 at ISO 1600.

What I find in Churchill is that even with numerically weak and visually dim shows, as above, the camera often sees very red and photogenic auroras. The eye sees the colours only when the aurora brightens, which it often does (as I record below), sparking rippling green curtains (from glowing oxygen) fringed with pink (from glowing nitrogen).

I didn’t shoot time-lapses or movies this year in Churchill. Instead, the example movie above, shot using just real-time (not time-lapse) videos, is from February 2019. It is from my AmazingSky YouTube channel.

The video presents the aurora much as the eye saw it, and as it appears when it dances.

This is a 360º panorama of the all-sky aurora of February 10, from the Churchill Northern Studies Centre. This is a panorama of 9 segments, each 15 seconds with the TTArtisan 11mm lens at f/2.8 on the Canon R6 at ISO 1600.

However, I tend now to shoot mostly panoramas, as above, from this year’s visit. They can take in the full show across the sky, in high-resolution images suitable for framing!

May 10 — The Great May Display

The aurora apps were beeping this day, warning a great display was in the offing. The composite satellite image below from NOAA shows the actual extent of the aurora around the Northern Hemisphere during the great display of May 10/11 .

Note how the auroral oval is indeed an oval and how the centre is not the geographic North Pole. It is the North Geomagnetic Pole, in the High Arctic of Canada. 🇨🇦 So the oval dips down farther south over North America than it does over Europe.

Image courtesy of the U.S. National Oceanic and Atmospheric Administration.

The May 10 solar storm rated a top “G5” on the G1 to G5 storm scale, while the “Kp”geomagnetic disturbance index reached Kp8 on the Kp0 (nothing) to Kp9 (OMG!) scale.

I gave a talk at a local community art gallery that evening, and alerted the audience to the likelihood of fine aurora later that night. Sure enough, I got home in time to see the sky already lighting up with aurora in the twilight and behind the clouds.

This was the multi-coloured curtain to the south during the great display of May 10. This is a 10-second exposure with the Laowa 15mm lens at f/2.8 on the Canon Ra at ISO 1600.

The clouds cleared off enough to reveal one of the most colourful shows I’d seen in many years. This time there was no question about seeing reds and vivid pinks with the unaided eye. This was the type of show everyone hopes for. But it takes a Kp6 show and higher to spark it.

This was the view as the aurora suddenly brightened and converged at the zenith for a superb corona effect. This lasted no more than a minute before it dimmed and subsided again. This is a 9-second exposure with the Laowa 7.5mm circular fisheye lens at f/2 on the Canon R5 at ISO 800.

I blogged previously about the Great May Aurora Display here.

And a music video of the May 10 display incorporating time-lapse and real-time video footage is on my YouTube channel, with the clickable link below. Do enlarge to full screen.

One of the most remarkable aspects of this show was the blue auroras later in the night (shown below), created by sunlight illuminating the upper curtains and reacting with atmospheric nitrogen. The usual auroral greens and reds are from oxygen. Pinks are also from nitrogen. Blues are less common, but were in abundance this night.

This is a 360° panorama of the May 10/11 aurora exhibiting vertical blue and magenta rays across the western (left), northern (bottom), and eastern (right) sky, and an odd bright patch to the south at top. This was toward the end of the main activity this night, at about 2:30 am. This is made of 20 segments, each 13-second exposures, with the Laowa 15mm lens at f/2 on the Canon Ra at ISO 800.

Auroras around summer solstice, June 21, can be more colourful and often blue, as the Sun lights the upper atmosphere all night. I saw blue auroras again later in the summer.

July — NLCs and Classic Auroral Arcs

June and July are normally when we in western Canada get good displays of another northern mid-latitude phenomenon, noctilucent clouds (NLCs).

This shows sunlit noctilucent clouds in the northwest in the summer twilight, and as the waxing crescent Moon sets at left. This was July 9 at 11:45 pm MDT, in a panorama of 5 segments, each a 30-second exposure with the Canon RF24-105mm lens at f/4 and 58mm on the Canon R5 at ISO 400.

These are ice clouds at 80 km altitude (almost in space) that are lit by sunlight all night long. I saw only a couple of displays of NLCs this year, and it wasn’t for lack of trying and clear nights, even amid forest fire smoke. The panorama above is from home on July 9, over a yellow canola field. NLC season always coincides with peak canola colour time!

Might NLCs be suppressed by high solar activity? There’s some data that suggests they are. However, we weren’t getting many auroras either in early summer.

A 180° panorama of the surprise aurora of July 25, as there was little indication in the days before that an aurora was possible this night. This is a panorama of 6 segments, with the Viltrox 16mm lens at f/2 on the Nikon Z6III at ISO 800, each 8-second exposures.

But at the end of July the Northern Lights returned for some classic shows of arcs across my northern sky, first on July 25 (above), with a prominent sunlit blue/purple ray at left by the Big Dipper. The Kp Index reached Kp5 this night, which is enough to produce a good display from my location in southern Alberta. The Moon is rising at right.

A 180° panorama of the Kp5-level aurora on July 29, with a green arc, and magenta and red rays. This is a panorama of 8 segments, each 30-second exposures with the Viltrox 16mm at f/2 on the Nikon Z6III at ISO 800.

Then again, four nights later on July 29, an auroral arc appeared across the north, this one with reds mixing with greens to create a yellow band in the east, as well as blue and magenta tops to the green arc that follows the curve of the auroral oval.

August 1 — STEVE Appears

While June and July were quiet months, August made up for them.

Of all the auroras this year, only this one, on August 1, produced a showing of STEVE, at least as best I saw in 2024. He can be elusive and easily missed!

This is a capture of a faint appearance of a STEVE-like arc during the Kp5 aurora of July31/Aug 1. This was at 12:10 a.m. MDT, so on Aug 1. The camera recorded the pinkish rays at right which are likely STEVE arcs below a more diffuse and fainter red band which may be a SAR, a Stable Auroral Red arc.

STEVE is the odd arc, often white or mauve, that appears southward of the main aurora (from here in the Northern Hemisphere), typically after a show has peaked, then subsided and retreated back north, as it did above.

STEVE stands for Strong Thermal Emission Velocity Enhancement, as it is caused by horizontally flowing hot gas, and so is not, by definition, a true aurora created by energetic particles raining vertically down magnetic field lines.

For a classic showing of STEVE see my video, above, from August 2022. High-resolution 4K video I shot this night formed the basis for a scientific research paper, as it revealed structures in STEVE no one had seen before.

This is a capture of a brief appearance of a STEVE arc in the west during the Kp5 aurora of July31/Aug 1. This was at 1:10 a.m. MDT, so on Aug 1. The mauve STEVE arc was visible for about 15 minutes before it gradually faded. The green picket fence fingers, which were visible to the eye but colourless, appeared only a minute or so before this image and were gone no more than 2 mnutes later.

STEVEs are often accompanied by green “picket fence fingers” hanging down from the mauve arc. These fingers are more akin to normal auroras, but are created by particles from the STEVE band raining down local magnetic field lines. They do not come from far out in space as they do in a normal aurora!

August 4 — A Coronal Outburst

On the night of August 3/4 I was able to join a photo tour run by local photographer Neil Zeller, to shoot Milky Way nightscapes. Escaping clouds, we ended up at a scenic spot south of Medicine Hat, Alberta, called Red Rock Coulee.

A 180° panorama of a Kp5-level aurora on a partly cloudy night, August 3/4. This was looking to the northeast at 3:00 am from a side road off the Trans-Canada Highway in southern Alberta just east of Brooks.

On the way home, the aurora began to let loose behind the clouds. We stopped once off the highway as the aurora brightened in an arc across the northeast, above.

A bright auroral curtain sweeps from the zenith down the western sky, as the sky brightens with the blue of a dawn twilight. This was the morning of August 4, with a Kp5 to 6 level aurora underway. The location was just off Highway 1 between Brooks and Bassano, Alberta. This is a single 13-second exposure with the Viltrox 16mm lens at f/2 on the Nikon Z6III at ISO 400.

We stopped again later, now at 4 am, and marvelled as the curtains converged at the zenith in the finest manifestation an aurora can produce, a swirling zenith “corona.”

A music video from August 4, using just a single real-time video, not a time-lapse, is above. It shows almost the full but brief appearance of the corona, just as the eye saw it looking straight up!

August 11 — Another Great Display

August was a good month! Right after the annual Saskatchewan Summer Star Party in the Cypress Hills I headed farther east to Grasslands National Park, a favourite dark-sky site I had not visited since 2019.

My plan was to shoot the annual Perseid meteor shower that was to peak on Sunday, August 11, from the same spot I shot it in 2016.

A 270° panorama of the aurora in the evening twilight on August 11, from the 70 Mile Butte trailhead in Grasslands National Park, West Block near Val Marie, Saskatchewan. This is a panorama of 11 segments, each 15 seconds with the Laowa 15mm lens at f/2.8 on the Canon R5 at ISO 800.

The aurora had other plans. Again, as it did on May 10, the sky was lighting up with colours as it darkened in the evening twilight, above.

This is a 360° all-sky panorama of the Kp6 to 7-level aurora on August 11, from Grasslands National Park. This is a panorama of 12 segments, each 4 seconds with the Laowa 15mm lens at f/2 on the Canon R5 at ISO 4000.

The aurora expanded to fill the sky, and with odd fragmented bits, shown above. My trio of cameras set up for the meteor shower got repurposed into taking aurora time-lapses, stills, and panoramas. And selfies! — the title slide for this blog was from this memorable night at Grasslands.

The aurora was bright enough during this substorm outburst at 12:15 am that the red and green colours could be seen with the eye, though they were subtle. This is a 2-second exposure with the Laowa 15mm lens at f/2 on the Canon R5 at ISO 3200.

A notable moment was at midnight when, even to the eye, the sky to the east suddenly turned red, and a wave of crimson aurora quickly swept in. The reds from oxygen mix with the more usual auroral greens, also from oxygen, to create areas of yellow in the sky.

This was also peak night for the 2024 Perseid meteor shower. One bright Perseid meteor shoots down the Milky Way in Cygnus at top, amid the converging rays of the aurora at the magnetic zenith. This is with the Laowa 10mm lens at f/2.8 on the Nikon Z6III at ISO 6400 for 2 seconds.

A few still frames in the time-lapses did manage to catch a Perseid meteor or two, as above, embedded in the vivid curtains of light. But the meteors were upstaged by the Northern Lights this night.

A music video of this show is above, also on my YouTube channel (it’s been a busy year!). Using only time-lapses, it captures the sudden arrival of the red sub-storm, sped up to be sure, but it seemed that quick!

August 30 — From Onset to Recovery

This night I was hoping to shoot deep-sky objects with telescopes I was testing at home. Again, the aurora had other ideas.

This view is looking north, but the fisheye lens is taking in much of the sky. The August 30 show was somewhat unexpected, though there were last-hour warnings a sky-covering display might be possible. This is a single 4-second exposure with the TTArtisan 7.5mm fisheye lens at f/2 on the Nikon Z6III at ISO 3200.

As the movie shows, a band of Lights across the north early in the evening promised to develop. So I set up a time-lapse camera and fisheye lens to capture, for once, a complete development of an aurora, from a diffuse band, to the onset of an active sub-storm outburst which occurred, as they often do, at midnight when we are looking down Earth’s magnetic tail at the source of the aurora particles.

As the video shows, the storm then subsides and the aurora changes character. During the post-sub-storm “recovery phase,” usually when we are under the dawn sector of the auroral oval, an aurora can switch to a pulsating effect with patches of aurora flashing off and on and flaming up to the zenith. This form of aurora is caused by electrons trapped in the Van Allen radiation belts that are bouncing back and forth from pole to pole.

To capture this aspect of the show I switched to real-time video with that same lens, reviewed here on a previous blog.

The music video of this show, above, uses a mix of time-lapses and real-time videos shot with the 360º 7.5mm fisheye lens. It’s a great aurora lens for capturing it all!

September 16 — A Colourful All-Sky Show

Auroras are often most frequent, active, and bright around the spring and autumn equinoxes, when the magnetic field lines of Earth and interplanetary space better connect. It’s called the Russell-McPherron Effect.

This is a 360° panorama from left (southeast) to right (northeast) and extending from the horizon to the zenith, taking in the entire sky during an outburst of a particularly colourful aurora on September 16. This is a panorama of 12 segments, each 4 seconds with the Laowa 15mm lens at f/2 on the Canon R5 at ISO 400.

September 16 (6 days before the autumnal equinox) saw another all-sky show that, for us in western Canada, rivalled May 10. As with the spring show, this aurora was notable for its great range of colours, with nitrogen pinks and magentas mixed in with shades of oxygen yellow-greens and reds.

A darker blue-green band to the south (at left above) during the peak could be aurora from incoming protons exciting hydrogen, not from the usual electrons that excite all other auroras and light up oxygen and nitrogen atoms and molecules.

Yes, there are proton auroras. Another research paper using my images from an October 2021 aurora explored the relationship between proton auroras and SAR arcs (explained below).

This is an all-sky 360° panorama from the horizon at the edges, to the zenith at centre, taking in the entire sky during an outburst of a particularly colourful aurora on September 16. This is a panorama of 12 segments, each 4 seconds with the Laowa 15mm lens at f/2 on the Canon R5 at only ISO 400.

The September 16 show started with a diffuse band which quickly exploded as a sub-storm onslaught of energetic particles arrived to light up the aurora with greater brilliance, colours, and rapid motion. The onset of a substorm can happen in literally just a minute.

Even the nearly Full Moon failed to diminish this show, seen from home under perfect skies. Luckily, the smoky season had abated.

A music video of this night’s show is also above on YouTube. Do click through to watch this and the other videos in full screen mode.

October 10 — Red Aurora from Arizona

Six months to the day after the great May 10 show, the sky erupted again with auroras seen all over the world, even from more southerly latitudes that don’t normally see Northern Lights.

A rare red aurora seen from latitude +32º N from southeast Arizona during the major Kp8-level storm of October 10. This is looking north from the Quailway Cottage near Portal, Arizona and Rodeo, New Mexico. This is a single 15-second exposure with the Canon RF15-35mm lens at 15mm and f/2.8 on the Canon R5 at ISO 1600.

I know because I was at one of those latitudes, in southern Arizona at 32° N. The aurora created the kind of show seen from areas that don’t normally get auroras — a red sky on the horizon. It is these ominous red skies that provoked Medieval fears of divine wrath and myths of armies clashing in the distant North.

Red auroras can also occur in the Southern Hemisphere (as can every other form of aurora) when the aurora australis brightens and extends farther north than normal, lighting up the southern sky red at locations that rarely see the Southern Lights.

In both cases we are seeing just the red tops of distant curtains that mostly lie hidden over the horizon, the red coming from oxygen reactions that can happen only at the rarefied altitudes of 300 to 500 km. Oxygen greens come from 100 to 300 km up.

From Arizona, I saw what many in the U.S. saw this night — a prominent glow, obviously red even to the eye, across the northern horizon. I was missing a far better show at home!

This is a 360° panorama covering the entire sky and extending up to the zenith at centre, capturing a rare SAR (Stable Auroral Red) arc across the Arizona sky in the pre-dawn hours of October 11. This is a panorama of 12 segments, each 30 seconds at f/2.8 with the Canon RF15-35mm lens on the Canon R5 at ISO 3200.

But unique to my more southerly site was this phenomenon, also widely seen across the U.S. and southern Canada.

Accompanying the “normal” aurora to the north was a diffuse red (to the camera) arc across the sky that lasted most of the night. This was a Stable Auroral Red (SAR) arc, created by thermal energy flowing horizontally in the high atmosphere some 400 km up.

SARs have been seen evolving into STEVEs, as the mechanisms seem related. Indeed, one of my images from August 1, shown above, seems to show a SAR/STEVE hybrid.

I set up a wide-angle lens and time-lapse hoping to catch such an evolution first-hand, which would have been of great interest to researchers. Alas, the SAR did not cooperate, stubbornly remaining a SAR all night.

This was the pre-dawn scene from southeastern Arizona on the morning of October 11 that frames a suite of skyglows. This is a panorama of 3 segments, each a stack of 5 x 1-minute tracked exposures with the Canon RF15-35mm lens at 15mm and f/2.8 on the Canon R5 at ISO 1600.

By dawn, with blue sunlight at work, the SAR looked magenta in the twilight, accompanied by two other sky glows:

The pyramid-shaped Zodiacal Light created by sunlight reflecting off cometary and meteoric dust in the inner solar system,
And the winter Milky Way, created by the combined light of distant stars in our section of our Galaxy.
So in one image we have atmospheric, interplanetary, and interstellar sky glows! This was truly an amazing sky, the likes of which I might never see again.

Ending the Year — November in Norway

In early November I headed to Norway to instruct my first aurora group there since 2019. The location was on board a ship, the m/s Nordkapp, a ferry in the Hurtigruten fleet that does 12-day runs along the coast, from Bergen in the south, to Kirkenes in the far north, and back again.

Passengers on board the m/s *Nordkapp* are watching the Northern Light show on November 9, from the coast of Norway. This is 0.4 seconds at f/1.8 with the Nikkor 20mm lens on the Nikon Z6III at ISO 3200.

We got three nights in a row of active auroras on the northbound voyage. A Kp4 to 5 storm brought the Lights farther south and overhead for us early in the voyage, something we don’t normally see in Norway until we get underneath the auroral oval, which at that longitude in the world lies above the Arctic Circle, north of 66° latitude.

A colourful aurora appears in the darkening evening twilight sky at sea along the coast of Norway on November 9. This is a single 2-second exposure with the 20mm Nikkor lens at f/1.8 on the Nikon Z6III at ISO 1600.

But on November 9, with a storm underway, the show started early, rudely interrupting our group’s cocktail hour as we all rushed up on deck. As it can do, the aurora glowing in a twilight sky took on added tints.

This is a panorama of auroral arcs across the southern sky, with prominent red content contrasting with the oxygen yellow-green bands. Taken on November 10/11 (just after midnight). This is a panorama of 7 segments, each 1.3-second exposures with the Nikkor 20mm lens at f/1.8 on the Nikon Z6III at ISO 3200.

The next night, November 10, as we sailed through the mountainous Lofoten Islands, we were treated to an aurora with lots of red content, above. No two auroras are alike!

An arc of Northern Lights points the way into the narrow Trollfjord in the Lofoten Islands of Norway, as our ship, the m/s *Nordkapp* enters the fjord at night by searchlight. This is a 0.5-second exposure at f/1.8 with the Nikkor 20mm lens on the Nikon Z6III at ISO 1600.

A curtain of aurora also nicely pointed the way into the short but scenic Trollfjord, a fjord the ship captains like to navigate into for a memorable side trip as we slide through the narrow canyon with seemingly inches to spare.

A gallery of my Norway auroras is here on my website.

All going well, I will be back in Norway for two cruises in October. Join me!

A music video of real-time aurora sequences shot from on deck during my November 2024 Norway cruise is above on YouTube. Note the phones held high, the way most people now shoot the aurora, and usually with very good success!

What’s Coming for 2025?

We have more to look forward to in 2025.

First, it is likely that the Sun has not peaked, but may undergo a second peak of maximum activity in 2025 or 2026. A double peak is common at many solar maxes. Just look at the graph at the opening of the blog, and the previous peaks of Cycles 23 and 24.

Plus, the most energetic solar flares and storms often occur after the peak on the downward trend of activity. So we could well see more worldwide aurora displays like we had on May 10 and October 10 in the coming two to three years. The show is far from over!

Watch websites like SpaceWeather.com for aurora alerts and news of solar events coming our way.

— Alan, December 15, 2024 / AmazingSky.com

December 6, 2024February 14, 2025

Testing Wide-Angle Lenses on Nikon Z for Astrophotography

I test a trio of wide-angle, auto-focus lenses for astrophotography, all for Nikon Z mount: the Nikkor 20mm f/1.8 S, the Viltrox 16mm f/1.8, and the Laowa 10mm f/2.8 Zero D.

As a bonus, I also test a fourth lens: the TTArtisan manual-focus 7.5mm f/2 fish-eye.

NOTE: Images are large and may take a while to load.

While the selection of lenses for Nikon Z mirrorless cameras is not as diverse as it is for Sony E-mount, Nikon shooters have more brands of lenses to pick from than do users of Canon R mirrorless cameras. For nightscapes and Milky Way photography we want fast, wide-angle lenses, usually in the 14mm to 24mm range.

Canon, Nikon, and Sony all have excellent zoom lenses that cover the range. I use Canon’s RF 15-35mm L lens a lot, and reviewed it here on my blog from 2022.

But all these wide-angle zooms are f/2.8. While that’s a good speed for most astro work, having an even faster lens can be valuable. An aperture of f/2 or faster allows for:

— Shorter exposures for untrailed stars when shooting just on a tripod with no tracker.

— Capturing fainter and more numerous meteors during a shower.

— Rapid-cadence time-lapses of auroras, freezing the motions of curtains.

— Real-time movies of auroras and satellite passages at lower, less noisy ISO settings.

The Nikkor 20mm at f/1.8 allowed a short 1.3-second exposure for capturing the aurora from a ship off the coast of Norway, to minimize ship motion trailing the stars.

Also, stopping those faster lenses down to f/2.8 can sometimes yield better image quality than shooting with a native f/2.8 lens wide open.

Canon and Sony each have fast f/2 zooms that cover the range from 28mm to 70mm. While those focal lengths can be useful, both lenses are expensive and heavy. And they are still not wide enough for many astro subjects. For fast lenses with even shorter focal lengths we need to turn to “prime” lenses, ones with fixed focal lengths.

As of this writing Canon has few fast, wide primes for their RF lens mount (their new 24mm f/1.4 VCM is a costly choice designed primarily for video use). A few third-party lens makers offer fast (f/2 or faster) primes for Canon full-frame cameras, always as manual focus lenses. For example, Laowa has a 15mm f/2, and TTArtisan has a 21mm f/1.5.

Yes, Sigma now offers auto-focus 16mm and 23mm f/1.4 primes, and Samyang has a new 12mm f/2, but they are only for Canon RF-S cropped-frame cameras. Canon has yet to allow other companies to produce auto-focus lenses for their full-frame cameras.

Nikon has been restrictive as well. Sigma’s much-lauded Art series that includes the 14mm rectilinear (i.e. the horizon remains straight) and 15mm fish-eye (with a curved horizon), both f/1.4 and aimed at astrophotographers, are not offered for Nikon or Canon, only for Sony E-mount and Panasonic/Leica L-mount cameras.

However, while Sigma lenses are missing, there is a wider choice of third-party lenses for Nikon Z-mount compared to Canon RF, plus Nikon itself makes a very fine 20mm prime in their premium S-series.

That’s what I test here — three wide-angle rectilinear primes for Nikon Z: A 20mm Nikkor, and two third-party primes: one from Viltrox, their 16mm; and one from Laowa, their new 10mm.

As a bonus, I add in a test of a fast fish-eye lens, from TTArtisan, their 7.5mm f/2.

NOTE: All test images can be downloaded as full-resolution JPGs for closer inspection. Click or tap on the images.

Prices are from B&H Photo, but will vary with sales and special promotions.

The Nikkor 20mm S-Line Lens ($1,050)

I shot the northern summer Milky Way (below) with the three rectilinear wide-angle lenses (meaning these are not fish-eyes) with the camera on a star tracker, to prevent star trailing. The tracker was the Move-Shoot-Move Nomad, reviewed here on my blog.

The Nikon Z6III and 20mm Nikkor on the MSM Nomad tracker.

I shot with Nikon’s new Z6III, a 24-megapixel full-frame camera I reviewed in the December 2024 issue of Sky & Telescope magazine. It offers a number of excellent features for nightscape photography. Most notably, auto-focus lenses zip to the infinity focus point automatically when the camera is turned on, something I wish Canon cameras would do.

The Nikkor 20mm has a field of view along the long dimension of 84°.

The Nikkor 20mm is the widest prime lens in Nikon’s premium S-Line series. It offers what I consider to be an ideal focal length for most nightscape and wide-field Milky Way images.

While a 14mm lens is often thought of as the default nightscape lens, a 20mm presents less distortion (objects leaning in or stretched out at the corners) and a more natural perspective. Plus the lens can be made faster (in this case f/1.8), smaller, and not cost as much as an ultra-fast 14mm like the Sigma f/1.4 Art lens.

Nikkor 20mm Corner Aberrations

The four panels show the upper left corner, in the area outlined in the inset that shows the full frame.

Sharp stars right to the corners is the ideal for all forms of astro images. We don’t want stars to turn into winged seagulls or coloured streaks. They should remain as pinpoint as possible.

The Nikkor 20mm shows very little aberrations across the frame. Stars are elongated by tangential astigmatism and discoloured by lateral chromatic aberration only slightly and only at the extreme corners.

Stopping down the lens decreased the aberrations, but some residual astigmatism remained, even at f/4. However, the corner aberrations are low enough, and so restricted to the very corners, that this is a lens you can certainly use wide open at f/1.8, or perhaps at f/2, without any penalty of image sharpness.

Nikkor 20mm Vignetting

The four panels show the left side, as outlined in the inset. The inset is the f/1.8 sample.

Ideally, we also want images to be as fully-illuminated across the frame as possible. Light fall-off, or vignetting, creates dark corners with less signal reaching the sensor. Less signal gives rise to more noise, noticeable when brightening the corners in processing. That can reveal unsightly noise, banding, and discolouration in nightscapes, especially in the ground, often the darkest part of a scene, not the starry sky.

The 20mm shows a fair degree of edge and corner darkening when wide open at f/1.8. Stopping the lens down to f/2 improves the field illumination notably. And by f/2.8 the field is fairly uniformly lit. There is little need to go as slow as f/4.

In all, the Nikkor 20mm S is a superb lens ideal for nightscapes and Milky Way images.

The Viltrox AF 16mm STM ASPH ED IF ($580)

The new company Viltrox has been making a name for themselves recently with the introduction of a number of top-quality pro-grade lenses to compete with the best from any brand, and at much more affordable prices.

The horizontal field of view of the Viltrox 16mm is 100°.

Their 16mm is an auto-focus lens that, on the Nikon, can actually auto-focus on stars, as can the Nikkor 20mm. However, it, too, will zip to infinity focus when powered up. Plus two function buttons can be programmed to rack between two preset focus distances, one of which can be infinity.

The buttons at left are for preset distances.

A manual aperture ring (above left) has 1/3rd-stop detents, or it can be set to A for controlling the aperture in the camera.

A colour OLED display (above right) shows the focus distance and aperture, a nice way to confirm your settings at night. The display is too bright on the darkest nights; I cover it with red gel.

An option to turn it red using the Viltrox app would be welcome. Or to turn it off! ….

NOTE ADDED FEB 24, 2025 — I tested all lenses on a stock camera. But when used on an astro-modified camera with greater red and infra-red sensitivity, the Viltrox 16mm can add a noticeable red glow or flare to images, as a colleague has found and reported to me. I did confirm this with very long exposures and high ISOs with my stock Z6III. It barely shows up in dark frames boosted a lot for brightness (see below – it’s the faint magenta band across the centre of the frame).

But in modded cameras it is much more obvious. This comes from the lens’s top OLED display. The trick is to slightly dismount the lens, which turns the display off, but still maintains data contact to the camera. Viltrox is aware of the issue and has said they will fix it in a firmware update.

With Viltrox lens fully engaged and display ON

Uniquely, this and other Viltrox lenses have Bluetooth built in, for direct connection to a mobile device for firmware updates and lens settings, shown above. However, I found the app buggy; it would connect to the lens, but then refuse to allow settings to be changed, claiming the lens was not connected. Or the app would freeze, disconcerting during a firmware update. Luckily, that did not brick the lens.

Viltrox 16mm Corner Aberrations

The four panels show the small corner area outlined in the centre inset that shows the entire image.

At the extreme corners, the Viltrox shows some softness (perhaps from field curvature), but only minimal astigmatism and lateral chromatic aberration when wide open at f/1.8, and slightly sharper corners at f/2. At f/2.8 corner performance is nearly perfect, and certainly is at f/4.

This is a level of aberration correction even the most premium of lenses have a hard time matching.

Viltrox 16mm Vignetting

The panels show the left side outlined in the centre inset, which shows the f/1.8 image.

As is often the case with wider lenses, the Viltrox does show a great deal of vignetting at f/1.8, more so than the Nikkor 20mm. While this can be corrected in processing it will raise noise levels.

Stopping down to just f/2 helps, but the field becomes more uniform only at f/2.8, the sweet spot for this lens for the best all-round performance. But it offers the speed of f/1.8 when needed, such as for auroras.

If you prefer a wider field than a 20mm provides, the Viltrox 16mm (also available for Sony) is a great choice that won’t break the bank. Until Canon changes their third-party lens policy, Canon owners are out of luck getting this excellent lens.

The Venus Optics/Laowa 10mm Zero-D FF ($800)

The Laowa also accepts 77mm filters, unusual for such a wide lens..

The lens maker Venus Optics (aka Laowa) is known for its innovative and often unusual lens designs.

Introduced in 2024, their new 10mm offers the widest field available in a rectilinear (not fish-eye) lens for full-frame cameras. The “Zero-D” label is for the lens’s lack of pincushion or barrel distortion. Horizons remain straight no matter where they fall on the frame. However, objects at the corners become elongated a lot.

The Northern Lights in a superb display on August 11-12, 2024, at Grasslands National Park, Saskatchewan. This is with the Laowa 10mm wide open at f/2.8 on the Nikon Z6III at ISO 6400.

Even so, there’s a lot to be said for having a field that extends for 130° across the long dimension of a full-frame sensor. That’s more than enough to go from well below the horizon to past the zenith when the camera is in portrait orientation. Even in landscape orientation (as above) the lens covers nearly a 90° field across the short dimension, enough to go almost from horizon to zenith.

The f/2.8 speed is slower than the other lenses on test here, but is still faster than most ultra-wide lenses. Remarkably, it accepts common 77mm filters, the same as the Nikkor 20mm and Viltrox 16mm.

The 10mm is available as an auto-focus lens for Sony E and Nikon Z, and in manual focus versions for Canon RF and Panasonic L, oddly all at the same price.

Laowa 10mm Corner Aberrations

The four panels show the corner area outlined in the inset, at four apertures between f/2.8 and f/4.

Corner aberrations are much worse than in the 20mm and 16mm lenses, showing a fair degree of tangential and sagittal astigmatism, elongating stars radially and adding wings to them, respectively. The aberrations are larger and reach deeper into the frame than in the Nikkor and Viltrox lenses.

There’s also some lateral chromatic aberration adding blue and purple fringes to the stars at the corners. Stopping down to f/4 improves, but doesn’t eliminate, the aberrations.

Laowa 10mm Vignetting

The four panels show the left side, as outlined in the inset, which shows the f/2.8 image.

Edge and corner darkening were also worse than in the other lenses and required about a +50 setting to correct in Adobe Camera Raw, far less than the maximum of +100. So it’s still quite acceptable and correctable.

However, while stopping the lens down to f/4 improves vignetting, it does not eliminate it, still requiring a +40 correction. Vignetting will be a factor to deal with in all astrophotos with this ultra-wide lens.

Laowa 10mm Lens Flares

Three panels showing the Moon framed in the left corner (L), centred (C), and in the right corner (R).

With such a wide lens, the Moon or other bright light sources are bound to be within the frame. The Laowa exhibits a prominent internal lens flare when bright objects are in the corners, but just in the corners. Objects near the edge but centered are fine.

Showing the effect of decreasing aperture on the lens flare and bright light source.

Stopping down the lens adds diffraction spikes (or “sunstars”) to bright lights, but doesn’t eliminate the circular internal reflection. None of this is a serious issue for most images, but it is something to be mindful of when framing nightscapes.

With the Laowa 10mm lens at f/2.8 on the Nikon Z6III at ISO 3200. Note the Big Dipper at left and Orion at right.

In Milky Way and starfield images, constellations in the corners can distort into unnatural shapes that look odd, as I show above. While the lens can take in a great swath of sky, its distortion and corner aberrations make it less than desirable for tracked Milky shots.

An aurora in the dawn twilight on September 17, 2024. A 4-second exposure with the Laowa 10mm at f/2.8.

Where the Laowa 10mm really proves its worth is for auroras, as above, which can require as wide a field as you can muster. Note the flat horizon.

For ultra-wide nightscapes in a single image (not a panorama) with a natural looking (not curved) horizon, and for meteor showers, the Laowa is just the ticket.

BONUS TEST: The TTArtisan 7.5mm f/2 Fish-Eye ($140)

The TTArtisan has a fixed lens hood. Front filters are not possible without vignetting.

Technically, this lens is designed to be used on cropped-frame (or APS-sensor) cameras where it fills the frame with a curving horizon. But it works on a full-frame camera where it projects a circular image slightly larger in diameter than the short dimension of the frame, so not a complete circle as with a true circular fish-eye like the old Sigma 8mm f/3.5.

An aurora in the dawn twilight on September 17, 2024 in a 2-second exposure with the TTArtisan 7.5mm fish-eye lens at f/2 on the Nikon Z6III at ISO 800.

For all-sky auroras, this is ideal, where the TTArtisan’s fast f/2 speed is unprecedented in a fish-eye lens. That makes rapid-cadence time-lapses possible, as well as real-time movies. An example is here on my YouTube channel.

A stack of 4 x 4-minute exposures with the TTArtisan 7.5mm f/2 fish-eye lens stopped down to f/2.8 on the Nikon Z6III at ISO 1600, on the MSM Nomad tracker.

Or you can just capture the Milky Way from horizon to horizon, as above. For the latter, having stars sharp across the circular field is still desirable.

I have this lens for Canon RF as well, but that unit shows a noticeable softening of the left edge with defocused stars, likely from lens de-centering. I was told by TTArtisan that was a normal unit-to-unit variation and not a defect warranting replacement. Annoying!

I hesitated to buy one for my Nikon. But this is such a unique lens, and so affordable, I took the chance. The Nikon Z-mount version proved much better.

TTArtisan 7.5mm Edge Performance

There is no corner performance or vignetting to test here.

TTArtisan 7.5mm lens at f/2, showing the left side area shown in the blowups below.

Instead, I’m inspecting the same side on the Nikon Z version that caused a problem on my Canon version.

Comparing f/2 and f/2.8 edge aberrations.

The Nikon version looks fine, with stars sharp along the edge even at f/2, showing just a low level of astigmatism, to be expected in such a fast, wide lens. Stars tighten up a bit more at f/2.8. Most critically, the field was flat and in focus across the frame. There was no evidence of lens de-centering or optical defects.

The edges do show some discolouration and a soft edge to the image area. I also see two odd dark protrusions at the top of the frame. Looking through the lens, there’s nothing obvious intruding into the light path.

Keep in mind when used on a full-frame camera you’re seeing more of the projected image than was intended in the design.

The 7.5mm lens comes with a metal lens cap with a threaded centre disk. Remove it to create an aperture that vignettes the image to a smaller but complete circle.

The TTArtisan 7.5mm is a specialty lens to be sure. But at its low price it isn’t a big outlay to include in your lens arsenal, for unique all-sky images, of auroras, satellite passages, sky colours, and the Milky Way. And it is terrific for time-lapses and movies of the whole sky. It is a no-frills manual lens available for most camera mounts.

Recommendations

The Viltrox 16mm, Laowa 10mm and TTArtisan 7.5mm are all available for Sony E-mount. The Laowa and TTArtisan are available for Canon RF, but the Viltrox 16mm is not, as it is an auto-focus, full-frame lens, the class of lenses Canon has yet to allow on their RF mounts, much to the disdain of all concerned but Canon management it seems.

Viltrox 16mm — For nightscape use, the Viltrox 16mm might be the single best choice, as being the most versatile and affordable of the trio of wide-angle lenses. Its focal length is a good balance between the usual 14mm and what I think is a more useful 20mm.

Nikkor 20mm — I like the Nikkor 20mm for its lower level of vignetting, slightly tighter framing, and very sharp stars. I think a 20mm is an ideal focal length for many nightscapes and Milky Way scenes. But it is the most expensive lens tested here.

Laowa 10mm — While nearly as costly as the Nikkor 20mm, the Laowa 10mm is much more specialized and, I think, not as useful as the others for general nightscape and Milky Way shooting. But it is superb for auroras, if you are in a place where they are common, as they are here in Alberta. Otherwise, I think you’d find the 10mm a costly lens that might not see a lot of use for astrophotography. Its real forté is architecture and real-estate interiors.

TTArtisan 7.5mm — Ditto on its limited use. But it is so affordable it’s easy to justify even if it doesn’t get a lot of use. The astro images, time-lapses, and movies it can produce are unique and impossible to create any other way. Be sure to buy it from a source where you can return it easily if you find your sample defective.

Reason To Go Mirrorless

The quality of these and other premium lenses from Nikon, and also from Canon, Sony and third-party makers like Sigma and Viltrox, is one of the major benefits of migrating to mirrorless cameras. DSLRs, and the lenses made for them, are now effectively dead as new gear choices.

Yes, mirrorless cameras can be better in many aspects of their operation than DSLRs. But it is the lenses made for mirrorless that show the greatest improvement over their DSLR equivalents, many of which date back to the forgiving film days.

— Alan, December 6, 2024 (amazingsky.com)

September 22, 2017December 3, 2017

The Fast 14s Face-Off

Sigma and Rokinon 14mm on Stars

I put two new fast 14mm lenses to the test: the Sigma 14mm f/1.8 Art vs. the Rokinon 14mm f/2.4 SP.

Much to the delight of nightscape and astrophotographers everywhere we have a great selection of new and fast wide-angle lenses to pick from.

Introduced in 2017 are two fast ultra-wide 14mm lenses, from Sigma and from Rokinon/Samyang. Both are rectilinear, not fish-eye, lenses.

I tested the Nikon version of the Sigma 14mm f/1.8 Art lens vs. the Canon version of the Rokinon 14mm f/2.4 SP. I used a Nikon D750 and Canon 6D MkII camera.

I also tested the new faster Rokinon SP against the older and still available Rokinon 14mm f/2.8, long a popular lens among nightscape photographers.

The Sigma 14mm is a fully automatic lens with auto focus. It is the latest in their highly regarded Art series of premium lenses. I have their 20mm and 24mm Art lenses and love them.

The Rokinon 14mm SP (also sold under the Samyang brand) is a manual focus lens, but with an AE chip so that it communicates with the camera. Adjusting the aperture is done on the camera, not by turning a manual aperture ring, as is the case with many of Rokinon’s lower cost series of manual lenses. The lens aperture is then recorded in each image’s EXIF metadata, an aid to later processing. It is part of Rokinon’s premium “Special Performance” SP series which includes an 85mm f/1.2 lens.

All units I tested were items purchased from stock, and were not supplied by manufacturers as samples for testing. I own these!

CONCLUSIONS

For those with no time to read the full review, here are the key points:

• The Sigma f/1.8 Art exhibits slightly more off-axis aberrations than the Rokinon 14mm SP, even at the same aperture. But aberrations are very well controlled.

• As its key selling point, the Sigma offers another full stop of aperture over the Rokinon SP (f/1.8 vs. f/2.4), making many types of images much more feasible, such as high-cadence aurora time-lapses and fixed-camera stills and time-lapses of a deeper, richer Milky Way.

• The Sigma also has lower levels of vignetting (darkening of the frame corners) than the Rokinon 14mm SP, even at the same apertures.

• Both the Sigma Art and Rokinon SP lenses showed very sharp star images at the centre of the frame.

• Comparing the new premium Rokinon 14mm SP against the older Rokinon 14mm f/2.8 revealed that the new SP model has reduced off-axis aberrations and lower levels of vignetting than the lower-cost f/2.8 model. However, so it should for double the price or more of the original f/2.8 lens.

• The Rokinon 14mm SP is a great choice for deep-sky imaging where optical quality is paramount. The Sigma 14mm Art’s extra speed will be superb for time-lapse imaging where the f/1.8 aperture provides more freedom to use shorter shutter speeds or lower ISO settings.

• Though exhibiting the lowest image quality of the three lenses, the original Rokinon 14mm f/2.8 remains a superb value, at its typical price of $350 to $500. For nightscapers on a budget, it’s an excellent choice.

TESTING PROCEDURES

For all these tests I placed the camera and lens on a tracking mount, the Sky-Watcher Star Adventurer Mini shown below. This allowed the camera to follow the sky, preventing any star trailing. Any distortions you see are due to the lens, not sky motion.

Sigma on SAM on Stars — Star Adventurer Mini Tracker (with Sigma 14mm on Nikon D750)

As I stopped down the aperture, I lengthened the exposure time to compensate, so all images were equally well exposed.

In developing the Raw files in Adobe Camera Raw, I applied a standard level of Contrast (25) and Clarity (50) boost, and a modest colour correction to neutralize the background sky colour. I also applied a standard level of noise reduction and sharpening.

However, I did not apply any lens corrections that, if applied, would reduce lateral chromatic aberrations and compensate for lens vignetting.

So what you see here is what the lens produced out of the camera, with no corrections. Keep in mind that the vignetting you see can be largely compensated for in Raw development, with the provisos noted below. But I wanted to show how much vignetting each lens exhibited.

OFF-AXIS ABERRATIONS

Stars are the severest test of any lens. Not test charts, not day shots of city skylines. Stars.

The first concern with any fast lens is how sharp the stars are not only in the centre of the frame, but also across the frame to the corners. Every lens design requires manufacturers to make compromises on what lens aberrations they are going to suppress at the expense of other lens characteristics. You can never have it all!

However, for astrophotography we do look for stars to be as pinpoint as possible to the corners, with little coma and astigmatism splaying stars into seagull and comet shapes. Stars should also not become rainbow-coloured blobs from lateral chromatic aberration.

SIGMA 14mm ART

Sigma 14mm Upper L Corner — Sigma 14mm Art – Upper Left Corner Close-up at 5 Apertures

Sigma 14mm Upper R Corner — Sigma 14mm Art – Upper Right Corner Close-up at 5 Apertures

These images show 200% blowups of the two upper corners of the Sigma 14mm Art lens, each at five apertures, from wide open at f/1.8, then stopped down at 1/3rd stop increments to f/2.8. As you would expect, performance improves as you stop down the lens, though some astigmatism and coma are still present at f/2.8.

But even wide open at f/1.8, off-axis aberrations are very well controlled and minimal. You have to zoom up this much to see them.

There was no detectable lateral chromatic aberration.

Aberrations were also equal at each corner, showing good lens centering and tight assembly tolerances.

ROKINON 14mm SP

Rokinon 14mm Upper L Corner — Rokinon 14mm SP at 3 Apertures

Rokinon 14mm Upper R Corner — Rokinon 14mm SP at 3 Apertures

Similarly, these images show 200% blow-ups of the upper corners of the Rokinon SP, at its three widest apertures: f/2.4, f/2.8 and f/3.2.

Star images look tighter and less aberrated in the Rokinon, even when compared at the same apertures.

But images look better on the left side of the frame than on the right, indicating a slight lens de-centering or variation in lens position or figuring, a flaw noted by other users in testing Rokinon lenses. The difference is not great and takes pixel-peeping to see. Nevertheless, it is there, and may vary from unit to unit. This should not be the case with any “premium” lens.

SIGMA vs. ROKINON

Rokinon vs Sigma (Corner Aberrations) — Rokinon vs. Sigma Corner Aberrations Compared

This image shows both lenses in one frame, at the same apertures, for a more direct comparison. The Rokinon SP is better, but of course, doesn’t go to f/1.8 as does the Sigma.

ON-AXIS ABERRATIONS

We don’t want good performance at the corners if it means sacrificing sharp images at the centre of the frame, where other aberrations such as spherical aberration can take their toll and blur images.

These images compare the two lenses in 200% blow-ups of an area in the Cygnus Milky Way that includes the Coathanger star cluster. Both lenses look equally as sharp.

SIGMA 14mm ART

Sigma 14mm Centre — Sigma 14mm Art – Centre of Frame Close-up

Even when wide open at f/1.8 the Sigma Art shows very sharp star images, with little improvement when stopped down. Excellent!

ROKINON 14mm SP

Rokinon 14mm Centre — Rokinon 14mm SP – Centre of Frame Close-up

The same can be said for the Rokinon SP. It performs very well when wide open at f/2.4, with star images as sharp as when stopped down 2/3rds of an f-stop to f/3.2

SIGMA vs. ROKINON

Rokinon vs Sigma (Centre Aberrations) — Sigma vs. Rokinon Centre Sharpness Compared

This image shows both lenses in one frame, but with the Sigma wide open at f/1.8 and stopped down to f/2.8, vs. the Rokinon wide open at f/2.4 and stopped to f/2.8. All look superb.

VIGNETTING

The bane of wide-angle lenses is the light fall-off that is inevitable as lens focal lengths decrease. We’d like this vignetting to be minimal. While it can be corrected for later when developing the Raw files, doing so can raise the visibility of noise and discolouration, such as magenta casts. The less vignetting we have to deal with the better.

As with off-axis aberrations, vignetting decreases as lenses are stopped down. Images become more uniformly illuminated across the frame, with less of a “hot spot” in the centre.

SIGMA 14mm ART

Sigma 14mm Vignetting (5 Apertures) — Sigma 14mm Art – Vignetting Compared at 5 Apertures

This set compares the left edge of the frame in the Sigma SP at five apertures, from f/1.8 to f/2.8. You can see how the image gets brighter and more uniform as the lens is stopped down. (The inset image at upper right show what part of the frame I am zooming into.)

ROKINON 14mm SP

Rokinon 14mm Vignetting (3 Apertures) — Rokinon 14mm SP – Vignetting Compared at 3 Apertures

This similar set compares the frame’s left edge in the Rokinon SP at its three widest apertures, from f/2.4 to f/3.2. Again, vignetting improves but is still present at f/3.2.

SIGMA vs. ROKINON

Rokinon vs Sigma Vignetting — Rokinon vs. Sigma – Vignetting Compared

This compares both lenses at similar apertures side by side for a direct comparison. The Sigma is better than the Rokinon with a much more uniform illumination across the frame.

Sigma 14mm Vignetting at f1.8 — Sigma 14mm Art – Vignetting at f/1.8 Maximum Aperture

Rokinon 14mm Vignetting at f2.4 — Rokinon 14mm SP – Vignetting at f/2.4 Maximum Aperture

In these two images, above, of the entire frame at their respectively widest apertures, I’d say the Sigma exhibits less vignetting than the Rokinon, even when wide open at f/1.8. The cost for this performance, other than in dollars, is that the Sigma is a large, heavy lens with a massive front lens element.

ROKINON 14mm f/2.4 SP vs. ROKINON 14mm f/2.8 Standard

Even the Rokinon 14mm SP, though a manual lens, carries a premium price, at $800 to $1000 U.S., depending on the lens mount.

Samyang 14mm Lens — The 14mm Rokinon/Samyang f/2.8 Lens

For those looking for a low-cost, ultra-wide lens, the original Rokinon/Samyang 14mm f/2.8 (shown above) is still available and popular. It is a fully manual lens, though versions are available with a AE chip to communicate lens aperture information to the camera.

I happily used this f/2.8 lens for several years. Before I sold it earlier in 2017 (before I acquired the Sigma 14mm), I tested it against Rokinon’s premium SP version.

The older f/2.8 lens exhibited worse off-axis and on-axis aberrations and vignetting than the SP, even with the SP lens set to the same f/2.8 aperture. But image quality of the original lens is still very good, and the price is attractive, at half the price or less, than the 14mm SP Rokinon.

TWO 14mm ROKINONS: OFF-AXIS ABERRATIONS

14mm Rokinons Aberrations (Upper L Corner) — Two Rokinons (Older “Standard” vs. new SP) – Upper Left Corner Close-up

14mm Rokinons Aberrations (Upper R Corner) — Two Rokinons (Older “Standard” vs. new SP) – Upper Right Corner Close-up

Here, in closeups of the upper corners, I show the difference between the two Rokinons, the older standard lens on the left, and the new SP on the right.

The SP, as it should, shows lower aberrations and tighter star images, though with the improvement most marked on the left corner; not so much on the right corner. The original f/2.8 lens holds its own quite well.

TWO 14mm ROKINONS: ON-AXIS ABERRATIONS

14mm Rokinons Aberrations (Centre) — Two Rokinons (Older “Standard” vs. new SP) – Centre of Frame Close-up

At the centre of the frame, the difference is more apparent, with the SP lens exhibiting sharper star images than the old 14mm with its generally softer, larger star images. The latter likely has more spherical aberration.

TWO 14mm ROKINONS: VIGNETTING

The new SP lens clearly has the advantage here, with less vignetting and brighter corners even when wide open at f/2.4 than the older lens does at its widest aperture of f/2.8. This is another reason to go for the new SP if image quality is paramount

PRICES

The new Sigma 14mm Art lens is costly, at $1600 U.S., though with a price commensurate with its focal length and aperture. Other premium lenses in this focal length range, either prime or zoom, from Nikon and Canon sell for much more, and have only an f/2.8 maximum aperture. So in that sense, the Sigma Art is a bargain.

The new Rokinon 14mm SP sells for $800 to $1000, still a premium price for a manual focus lens. But its optical quality competes with the best.

The older Rokinon 14mm f/2.8 is a fantastic value at $350 to $500, depending on lens mount and AE chip. For anyone getting into nightscape and Milky Way photography, it is a great choice.

RECOMMENDATIONS

With such a huge range in price, what should you buy?

A 14mm is a superb lens for nightscape shooting – for sky-filling auroras, for panoramas along the Milky Way, or of the entire sky. But the lens needs to be fast. All three lenses on offer here satisfy that requirement.

Sigma 14mm & Rokinon 14mm SP (Front) — Sigma 14mm Art (left) and Rokinon 14mm SP (right)

SIGMA 14mm f/1.8 ART

If you want sheer speed, this is the lens. It offers a full stop gain over the already fast Rokinon f/2.5, allowing exposures to be half the length, or shooting at half the ISO speed for less noise.

Its fast speed comes into its own for rapid cadence aurora time-lapses, to freeze auroral motion as much as possible in exposures as short as 1 to 2 seconds at a high ISO. The fast speed might also make real-time movies of the aurora possible on cameras sensitive and noiseless enough to allow video shooting at ISO 25,000 and higher, such as the Sony a7s models.

The Sigma’s fast speed also allows grabbing rich images of the Milky Way in exposures short enough to avoid star trailing, either in still images or in time-lapses of the Milky Way in motion.

While the Sigma does exhibit some edge aberrations, they are very well controlled (much less than I see with some 24mm and 35mm lenses I have) and are a reasonable tradeoff for the speed and low level of vignetting, which results in less noisy corners.

Photographers obsess over corner aberrations when, for fixed-camera nightscape shooting, a low level of vignetting is probably more critical. Correcting excessive vignetting introduces noise, while the corner aberrations may well be masked by star trailing. Only in tracked images do corner aberrations become more visible, as in the test images here.

I’d suggest the Sigma is the best choice for nightscape and time-lapse shooting, with its speed allowing for kinds of shots not possible otherwise.

The Sigma also appears to be the best coated of all the lenses, as you can see in the reflections in the lenses in the opening image, and below. However, I did not test the lenses for flares and ghosting.

As a footnote, none of the lenses allow front-mounted filters, and none have filter drawers.

ROKINON 14mm f/2.4 SP

For less money you get excellent optical quality, though with perhaps some worrisome variation in how well the lens elements are figured or assembled, as evidenced by the inconsistent level of aberration from corner to corner.

Nevertheless, stars are tight on- and off-axis, and vignetting is quite low, for corners that will be less noisy when the shadows are recovered in processing.

I’d suggest the Rokinon SP is a great choice if tracked deep-sky images are your prime interest, where off-axis performance is most visible. However, the SP’s inconsistent aberrations from corner to corner are evidence of lower manufacturing tolerances than Sigma’s, so your unit may not perform like mine.

For nightscape work, the SP’s f/2.4 aperture might seem a minor gain over Rokinon’s lower-cost f/2.8 lens. But it is 1/3 of an f-stop. That means, for example, untracked Milky Way exposures could be 30 seconds instead of 40 seconds, short enough to avoid obvious star trailing. At night, every fraction of an f-stop gain is welcome and significant.

ROKINON 14mm f/2.8 Standard

You might never see the difference in quality between this lens and its premium SP brother in images intended for time-lapse movies, even at 4K resolution.

But those intending to do long-exposure deep-sky imaging, as these test images are, will want the sharpest stars possible across the frame. In which case, consider the 14mm SP.

But if price is a prime consideration, the original f/2.8 Rokinon is a fine choice. You’ll need to apply a fair amount of lens correction in processing, but the lens exists in the Camera Raw/Lightroom database, so correction is just a click away.

That was a lengthy report, I know! But there’s no point in providing recommendations without the evidence to back them up.

All images, other than the opening “beauty shot,” can be clicked/tapped on to download a full-resolution original JPG for closer inspection.

As I’ve just received the Sigma Art lens I’ve not had a chance to shoot any “real” nightscape images with it yet, just these test shots. But for a real life deep-sky image of the Milky Way shot with the Rokinon SP, see this image from Australia. https://flic.kr/p/SSQm7G

I hope you found the test of value in helping you choose a lens.

Clear skies!