fish-eye – The Amazing Sky

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)

May 18, 2024May 18, 2024

The Great Aurora Show of May 10, 2024

It has been many years since we were treated to an aurora as widely seen as the show on May 10, 2024. Here’s my tale of the great display.

As the sky darkened around the world on May 10/11, 2024, sky watchers in both the northern and southern hemispheres were amazed to see the sky lit by the deep reds, greens and pinks of a massive display of aurora. For me, this was my first Kp8 to 9 show (to use one measure of aurora intensity) in more than 20 years, back in the film era!

Throughout the day, aurora chasers’ phones (mine included) had been beeping with alerts of the arrival of a major solar storm, with the usual indicators of auroral activity pinned to the top of the scale.

A NOAA satellite’s eye view of the ring of aurora May 10/11, showing it south of me in Alberta, and across the northern U.S. People in the southern U.S. saw it to their north.

As I show below, the graphic of the intensity of the band of aurora, the auroral oval, was lit up red and wide. This was a night we didn’t have to chase north to see the Northern Lights or aurora borealis — they were coming south to meet us (as I show above).

**The Kp Index was reading 9 on SpaceWeatherLive**

Observers in the southern hemisphere had the normally elusive aurora australis move much farther north than usual, bringing the Southern Lights even to tropical latitudes in Australia, South America and Africa.

The cause was a massive sunspot group on the Sun which had let off several intense solar flares.

Sunspot group 3664 was so big it could be seen with the naked eye, using solar eclipse glasses. Photo courtesy NASA.

The flares had in turn blown off parts of the Sun’s atmosphere, the corona, that anyone who saw the total eclipse a month earlier had admired so much. But a month later, the corona was being blown our way, in a series of Coronal Mass Ejections (CMEs), to collide with Earth.

A movie of six CMEs blasting toward Earth, captured by the SOHO satellite. Courtesy NASA/ESA.

As it happened I was scheduled to give a community talk in the nearby town early in the evening of May 10, on the topic of The Amazing Sky! Watching the indicators, I could more or less promise the audience that we would indeed see an amazing sky later that evening as it got dark.

Post talk, I hurried home to get the cameras ready, choosing to forgo more hurried driving out to a scenic site in southern Alberta, for the convenience of shooting from my rural backyard. As the sky darkened, the clouds were lit purple, and curtains of aurora appeared in the clear patches.

Clouds and aurora in twilight with the 11mm TTArtisan full-frame fish-eye lens.

A bright arc of aurora shining through the purple clouds, with the 7.5mm TTArtisan circular fish-eye lens.

Something big was going on! This was promising to be the best show of Northern Lights I had seen from home in a year. (Spring 2023 had three great shows at monthly intervals, followed by an aurora drought for many months. See The Great April Aurora.)

A selfie at the start of the great aurora show of May 10, 2024.

I shot with four cameras (a Canon EOS R, Ra, R5 and R6) — two for time-lapses, one for real-time movies, and one for still images. I used the latter to take many multi-image panoramas, as they are often the best way to capture the wide extent of an aurora across the sky.

The arc of aurora in purple and white across the northern sky from home in Alberta at the start of the great display (about 11:30 p.m. MDT).

Early in the evening the arc of aurora wasn’t the usual green from oxygen, but shades of purple, pink, and even white, likely from sunlit nitrogen. The panorama above is looking north toward a strangely coloured arc of nitrogen (?) aurora.

Then after midnight a more normal curtain appeared suddenly, but toward the south, brightening and rising to engulf much of the southern sky and the sky overhead.

Looking south with the 15mm wide-angle lens.

It is at local midnight to 1 a.m. when substorms usually hit, as we are then looking straight down Earth’s magnetic tail, toward the rain of incoming aurora particles bombarding the Earth. During a substorm, the rain turns into a deluge — the intensity of the incoming electrons increases, sparking a sudden brightening of the aurora, making it dance all the more rapidly.

This is a 300° panorama of my home sky now filled with colourful curtains.

As the aurora explodes in brightness it often swirls up to the zenith (or more correctly, the magnetic zenith) to form one of the sky’s greatest sights, a coronal outburst. Rays and beams converge overhead to form a tunnel effect. It is jaw-dropping.

I’ve seen this many times from northern sites such as Churchill and Yellowknife, where the aurora often dances straight up. And from my latitude of 51° N in western Canada, the aurora does often come down to us.

But this night, people at latitudes where, at best, the aurora might be seen just as a glow on the horizon, saw it dance overhead in a corona show to rival the solar eclipse, and that other corona we saw on April 8!

This is a panorama of a substorm outburst creating an overhead corona with rays converging to the magnetic zenith (south of the true zenith), and amid clouds. The rays show a rich mix of oxygen greens and reds, as well as nitrogen blues blending to create purples. Some greens and reds are mixing to make yellows.

Yes, the long exposures of aurora photos (even those taken with phone cameras) show the colours better than your eye can see them (insensitive as our eyes are to colour in dim light). But this night portions of the arcs and rays were bright enough that greens and pinks were easily visible to the naked eye.

This is a single 9-second exposure of the peak of a bright outburst at 1 a.m. MDT. It was with the Laowa 7.5mm circular fish-eye lens at f/2 on the Canon R5 at ISO 800. It is one frame from a time-lapse sequence.

A brief outburst of a substorm created an overhead corona with bright rays converging to the magnetic zenith (south of the true zenith).

At its peak the show was changing rapidly enough, I couldn’t get to all the cameras to aim and frame them, especially the movie camera. The brightest outburst at 1 a.m. lasted just a minute — the time-lapse cameras caught it. The sequence below shows the view in 9-second exposures taken consecutively just 1 second apart.

This series shows a brief outburst of bright aurora at the magnetic zenith overhead. The time between these 7 consecutive 9-second exposures is only 1 second, so this bright outburst did not last long (little more than a minute). With the TTArtisan 7.5mm f/2 fish-eye lens on the Canon R5. Click or tap to enlarge to full screen.

Here’s another sequence of frames taken as part of a time-lapse sequence with the 11mm lens. It shows the change in the aurora over the 80 minutes or so that it was most active for me at my site.

The time between these 12 images is usually 8 minutes, though to include some interesting activity at a bright outburst, the interval is 5 minutes for three of the images around 1 a.m. Each is a 7- or 9-second exposure taken as part of a time-lapse sequence using the 11mm TTArtisan lens at f/2.8 on the Canon R at ISO 800 or 1600.

Shooting time-lapses with fish-eye lenses captures the show with a minimum of attention needed (except to adjust ISO or exposure times when the aurora brightens!). I could use the still camera (with the Laowa 15mm f/2 lens) to take individual shots, such as more selfies and home shots.

This is a single 6-second exposure with the Laowa 15mm lens at f/2 and Canon Ra at ISO 2000.

This is a single 8-second exposure with the Laowa 15mm lens at f/2 on the Canon Ra at ISO 800. Another camera taking a time-lapse is in the scene. I had four going this night.

As colourful as the aurora was at its best between midnight and 1:30 a.m., I think the most unique shots came after the show had subsided to appear just as faint rays across the north again, much as it had begun. To the eye it didn’t look like much, but even on the camera’s live screen I could see unusual colours.

I took more panoramas, to capture one of the most unusual auroral arcs I’ve even seen — a blue and magenta aurora across the north, similar to how the night started.

This a stitch of 11 segments, each 13-second exposures, with the Laowa 15mm lens at f/2 on the Canon Ra camera at ISO 800, and turned to portrait orientation. Processed in Camera Raw and stitched with PTGui.

The colours may be from nitrogen glowing, which tends to light up in blues and purples, especially when illuminated by sunlight at high altitudes. At 2 to 2:30 a.m. the Sun might have been illuminating the aurora at a height of 150 to 400 km, and far to the north.

I’d seen blue-topped green auroras before (and there’s a green aurora off to the west at left here). But this was the first time I’d seen an all-blue aurora, no doubt a product of the intense energy flowing in the upper atmosphere this night. And the season and my latitude.

The panorama is a spherical projection spanning 360º, and reaching to the zenith 90° high at centre. This a stitch of 20 segments, each 13-second exposures, with the Laowa 15mm lens at f/2 on the Canon Ra camera at ISO 800, and turned to portrait orientation. Processed in Camera Raw and stitched with PTGui.

The weirdest aurora was at 2:30 a.m., when in addition to the blue rays of nitrogen, an odd white and magenta patch appeared briefly to the south. What was that??

The lesson here? During a bright show do not go back to sleep when things seem to be dying down. Interesting phenomena can appear in the post-storm time, as we’ve learned with STEVE and other odd red arcs and green proton blobs that we aurora photographers have helped document.

I end with a finale music video, mostly made of the time-lapses I shot this night.

Enjoy!

Bring on more aurora shows as the Sun peaks in activity, perhaps this year. But the best shows often occur in the 2 or 3 years after solar max. So we have several more years to look forward to seeing the Lights dance in our skies.

Watch in full screen and in 4K if you can. For all the tech details click through to YouTube and check the description below the video.

Thanks and clear skies!

— Alan, May 18, 2024 amazingsky.com

April 29, 2023May 18, 2024

The Great April Aurora

On April 23, 2023 the sky erupted with a massive solar storm, bringing the aurora to millions of people around the word.

On April 23 warnings went out alerting aurora watchers that a solar storm was imminent. And as the sky darkened that night locations all across the Northern and Southern Hemispheres were treated to a great sky show.

This is what we want to see in our aurora apps! Code Red and a vast auroral oval.

When we see this on our phone apps, we know we’ll get a great show. This was the auroral oval, lit up red, as the display was underway at my location in Alberta, Canada.

The strength of the interplanetary field (Bt) was high and the direction of the field (Bz) was well south, all welcome indicators of a superb show.

Sure enough, as it got dark that night, and from my location after the clouds cleared, an aurora was underway covering much of the sky.

A fish-eye 360° view of the Great April Aurora of April 23, 2023, from home in southern Alberta, Canada. The Kp level reached 7 to 8 this day. The Big Dipper is above centre. This is looking north. A single 5-second exposure with the TTArtisan 7.5mm circular fish-eye lens at f/2 and Canon R6 at ISO 3200.

The aurora moved south to occupy just the southern half of the sky, but with incredible ribbons crossing from east to west, rippling and pulsating off and on. Seeing patches of aurora pulse off and on and flaming up to the zenith is not uncommon toward the end of a substorm outburst. But this was the first time I can recall seeing pulsating ribbons.

At times, there was a dark ribbon across the sky, as the aurora formed a gap in its curtains, looking like a “dark aurora.”

The view looking straight up is always the most jaw-dropping when an aurora fills the sky. Rays and curtains converge at the magnetic zenith to form a “corona.”

The aurora of April 23, 2023, looking straight up to the zenith to capture the converging curtains in a coronal display. The Big Dipper is at top. A single 3.2-second exposure with the Canon R5 at ISO 800 and Laowa 15mm lens at f/2.

I shot with three cameras, taking stills, time-lapses, and real-time movies. I edited them together here in a music video. Enlarge to full screen to view it. I hope you enjoy it!

A 3-minute video of the April 23, 2023 aurora show from Alberta.

An aurora selfie with the great all-sky Kp6 to 8 level aurora of April 23, 2023. This is looking south toward Arcturus and Spica. The Coma Berenices cluster is at top near the convergence point for the auroral curtains. Shot from home with the Canon Ra and 11mm TTArtisan full-frame fish-eye lens at f/2.8.

With the Sun ramping up in activity, we should get more great shows of Northern – and Southern! – Lights around the world in the next few years,

August 11, 2022May 18, 2024

A Showing of STEVE

On August 7, 2022 we were treated to a fine aurora and a superb showing of the anomalous STEVE arc across the sky.

Where I live in southern Alberta we are well positioned to see a variety of so-called “sub-auroral” phenomena — effects in the upper atmosphere associated with auroras but that appear south of the main auroral arc, thus the term “sub-auroral.”

An arc of a Kp-5 aurora early in the evening just starting a show, but with a fading display of noctilucent clouds low in the north as well.

The main auroral band typically lies over Northern Canada, at latitudes 58° to 66°, though it can move south when auroral activity increases. However, on August 7, the Kp Index was predicted to reach Kp5, on the Kp 0 to 9 scale, so moderately active, but not so active it would bring the aurora right over me at latitude 51° N, and certainly not down over the northern U.S., which normally requires Kp6 or higher levels.

An arc of a Kp-5 aurora over a wheatfield from home in southern Alberta. The panorama takes in the northern stars, from the Big Dipper and Ursa Major at left, to the W of Cassiopeia at top right of centre, with Perseus below Cassiopeia, and Andromeda and Pegasus at right.

So with Kp5, the aurora always appeared in my sky this night to the north, though certainly in a fine display, as I show above.

However, at Kp5, the amount of energy being pumped into the magnetosphere and atmosphere around Earth is high enough to trigger (through mechanisms only beginning to be understood) some of the unique phenomena that occur south of the main aurora. These often appear right over me. That was the case on August 7.

This is a telephoto lens panorama of a low and late-season display of noctilucent clouds in the north on August 7, 2022. This was the latest I had seen NLCs from my latitude of 51° N.

I captured the above panoramas of the aurora early in the night, when we also were treated to a late season display of noctilucent clouds low in the north. These are high altitude water-vapour clouds up almost as high as the aurora. They are common in June and July from here (we are also in an ideal latitude for seeing them). But early August was the latest I had ever sighted NLCs.

A display of a Kp-5 aurora near its peak of activity on August 7, 2022, taken from home in southern Alberta, over the wheatfield next to my acreage. STEVE appeared later this night. Moonlight from the waxing gibbous Moon low in the southwest illuminates the scene.

As the NLCs faded, the auroral arc brightened, promising a good show, in line with the predictions (which don’t always come true!). The main aurora reached a peak in activity about 11:30 pm MDT, when it was bright and moving along the northern and northeastern horizon. It then subsided in brightness and structure, giving the impression the show was over.

But that’s exactly when STEVE can — and this night did! — appear.

A portrait of the infamous STEVE arc of hot flowing gas associated with an active aurora, here showing his distinctive pink colour and the fleeting appearance of the green picket fence fingers that often show up hanging down from the main arc.

Sure enough, about 12:15 am, a faint arc appeared in the east, which slowly extended to cross the sky, passing straight overhead. This was STEVE, short for Strong Thermal Emission Velocity Enhancement.

STEVE is not an aurora per se, which is caused by electrons raining down from the magnetosphere. STEVE is a ribbon of hot (~3000°) gas flowing east to west. STEVE typically appears for no more than an hour, often less, before he fades from view.

A fish-eye view looking straight up. On this night the green fingers lasted no more than two minutes.

At his peak, STEVE is often accompanied by green “picket-fence” fingers hanging down from the main pink band, which also have a westward rippling motion. These do seem to be caused by vertically moving electrons.

This night I shot with three cameras, with lenses from 21mm to 7.5mm, including two fish-eye lenses needed to capture the full extent of sky-spanning STEVE. I shot still, time-lapses, and real-time videos, compiled below.

Amateur photos like mine have been used to determine the height of STEVE, which seems to be 250 to 300 km, higher than the main components of a normal aurora. Indeed, previous images of mine have formed parts of the data sets for two research papers, with me credited as a citizen scientist co-author.

A closeup of the STEVE arc of hot flowing gas associated with an active aurora.

STEVE is a unique example of citizen scientists working with the professional researchers to solve a mystery that anyone who looks up at the right time and from the right place can see. August 7-8, 2022 and my backyard in Alberta was such a time and place.

A dim Perseid meteor (at top) streaking near the Milky Way on the night of Aug 7-8, 2022, taken as part of a time-lapse set for the STEVE auroral arc in frame as the pink band.

As a bonus, a few frames recorded Perseid meteors, with the annual shower becoming active.

For a video compilation of some of my stills and videos from the night, see this Vimeo video.

A 2.5-minute music video of stills, time-lapses, and real-time videos of STEVE from August 7-8, 2022.

Thanks! Clear skies!

— Alan Dyer, amazingsky.com

May 1, 2017

The Amazing Austral Sky

Panorama of the Milky Way Overhead

The latitude of 30° South is the magic latitude on Earth for seeing the Milky Way.

From that region of the world – southern Australia, central South America, southern Africa – the centre of the Galaxy passes overhead, and you see the view at top.

You see the galactic core glowing brightly at the zenith, and the arms of the Milky Way stretching off to the horizon on either side of the core – to Aquila at left, for the northern half of the Galaxy, and to Carina at right, for the southern half of the Galaxy. That area of the Galaxy is always below the horizon for viewers at northern latitudes.

The image below focuses in on just the southern portion of the Milky Way, framing what in Australia is called the “Dark Emu,” a constellation made of the dark lanes along the Milky Way, from his head at right in Crux, to his tail at left in Scutum.

The Dark Emu Overhead

This is the most amazing region of the Milky Way, and is worth the trip south of the equator just to see, by lying back and looking up. You can easily see we live in a vast Galaxy, and not in the centre, but off to one side looking back at the core glowing overhead.

I would say there are three sky sights that top the list for spectacle:

• A bright all-sky aurora

• A total solar eclipse

• and the naked eye view of the Galaxy with its centre overhead and its arms across the sky from horizon to horizon.

I’ve checked off two this year! One more to go in August!

June 23, 2015June 23, 2015

The Great Solstice Aurora of 2015

Aurora watchers were on alert! Look up after sunset on June 22 and the sky should be alive with dancing lights.

And the predictions were right.

I headed out to a nearby lake in preparation for seeing and shooting the show. And as soon as the sky got dark enough the Lights were there, despite the bright solstice twilight.

The display reached up to the zenith, as seen in my fish-eye images, like the one below. I shot with three cameras, all shooting time-lapses, with the fish-eye camera recording the scene suitable for projection in a digital planetarium.

However, it was apparent we here in western Canada were seeing the end of the display that had been going on for hours during an intense geomagnetic storm. The aurora was most intense early in the evening, with a minor outburst about 11:30 to 11:45 pm MDT.

The aurora then subsided in structure and turned into a more chaotic pulsating display, typical of the end of a sub-storm.

However, an attraction of this display was its juxtaposition over another storm, an earthly one, flashing lightning to the northwest of me.

By 1 a.m. MDT the display, while still widespread over a large area of the northern sky, had turned into a diffuse glow.

But 60 gigabytes of images later, I headed home. The time-lapse compilation will come later!

June 1, 2015June 2, 2015

Night of the Space Station

The Space Station is now continuously lit by sunlight, allowing me to capture dusk-to-dawn passages of the ISS.

On the night of May 31/June 1 I was able to shoot four passages of the International Space Station on successive orbits, at 90-minute intervals, from dusk to dawn.

The first passage, at 11:06 p.m., was low across the south. It’s the image at top.

Then at 12:45 a.m. the Space Station came over again, now directly overhead. It’s the image above. The Moon is the bright glow at bottom.

One orbit later, at 2:21 a.m., the Station came over in another overhead pass in the bright moonlight.

The final passage of the night came at 3:55 a.m. as the sky was brightening with dawn twilight and the Moon was setting. This was another passage across the south, and made for the most photogenic pass of the night.

Here’s an edited movie of the four passes, with a little music just for fun.

Seeing the Space Station on not one but two, three, or even four orbits in one night is possible at my latitude of 50 degrees north around summer solstice because the Station is now continuously lit by sunlight — the Sun never sets from the altitude of the ISS.

When the ISS should be entering night, sunlight streaming over the north pole still lights the Station at its altitude of 400 km.

To shoot the time-lapse clips and stills I used 8mm and 15mm fish-eye lenses, and a 14mm ultra-wide lens.

The bright moonlight made it possible to use short 2- to 4-second exposures, allowing me to record enough frames at each passage to make the little movies of the ISS flying across the sky. Keep in mind, to the eye, the ISS looks like a bright star. Some image processing trickery adds the tapering trails.

I used the Advanced Stacker Actions from StarCircleAcademy.com to create the trail effects, and to stack the time-lapse frames into single composite still images. The gaps in the trails are from the one second interval between frames.

May 11, 2015May 11, 2015

The Red Aurora of May 10

A strange red arc of aurora moved slowly across the sky on May 10.

All indicators looked favourable early in the evening on May 10 for a good auroral display later that night, and sure enough we got one. But it was an unusual display.

From my site in southern Alberta, the northern sky did have a diffuse glow of “normal” green aurora that never did take much form or structure.

But overhead the aurora took the form of an arc across the sky, starting as an isolated ray in the southeast initially, then reaching up to arch across the sky with what looked to the eye like a colourless band.

But the camera showed it as a red arc, with just a fringe of green curtains appearing for a few minutes.

Be sure to click HD and enlarge the video to fill your screen.

The time-lapse movie shows the sequence, over about 90 minutes, with 170 frames playing back at 12 frames per second. You can see the red arc develop, then become more narrow, then exhibit a few green curtains. Then it fades away.

Large-scale pulses also brighten the whole sky momentarily.

The other images are individual frames taken during the evening, showing snapshots of the red arc development, as it became more narrow in structure and gained green curtain-like fringes.

Presumably the red structure was very high in the atmosphere while the green curtains attached to it that did appear hung down from the high-altitude red arc.

I shot all images with an 8mm fish-eye lens to capture most of the sky. The camera is looking north toward Polaris, with the Big Dipper almost directly overhead near the centre of the frames.

The main image at top is a star-trail stack of 80 frames showing the sky’s circumpolar motion around Polaris and the aurora blurred and blended over 45 minutes of motion. I stacked the frames with the Advanced Stacker Actions from StarCircleAcademy.com

February 19, 2015February 19, 2015

The Colourful Curtains of the Northern Lights

All-Sky Aurora #1 (Feb 17, 2015)

The Northern Lights have performed beautifully the last few nights, presenting curtains of light dancing across the sky.

Two nights ago in Churchill, Manitoba we were treated to a “storm level” show of aurora, with the Lights all across the sky in green curtains waving and curling before our eyes.

The curtains tower several hundred kilometres up into the atmosphere, from the lower edge at about 80 km up (still high above the stratosphere) to the curtain tops at about 400 km altitude at the edge of space.

The camera picks up the colours far better than the eye can, recording not only the predominant green hues but also shades of pink, magenta and red.

The magentas and reds come from the sections of the curtains at the highest altitudes, from the top of the auroral curtains. Here, where the atmosphere is a near vacuum, sparse oxygen atoms can glow with a red emission line.

However, there must be a blue component as well, leading to the magenta or pink tones, as in my photos here. Nitrogen can glow in blues and purples and might be contributing to the colours.

The top two photos are from Tuesday night, Feb 17, when storm levels of 5 were in effect worldwide.

All-Sky Auroral Curtains #2 (Feb 18, 2015)

Lower down, at about 100 km altitude, the air is denser and oxygen glows with a brighter green hue, which the eye can detect more easily.

The photo above from last night, with an activity level of just 2, also shows most of the sky covered with a faint emission, with a patchy appearance, with dark “holes” also moving and flowing in the time-lapse movies I shot.

Closer to the horizon, and far to the north, the aurora brightens into the more characteristic green snaking curtains.

This image from three nights ago shows an usually coloured aurora at the start of the night, glowing mostly a deeper red and orange.

The green was still off in the distance far to the east. It arrived a few minutes later as green curtains swept in over us.

But the initial red was from low-energy electrons lighting up just high-altitude oxygen. Only when the higher energy particles arrived did the sky light up green.

I shot all these images with an 8mm fish-eye lens as frames in time-lapse sequences intended for use projected in digital planetarium domes, where the 360° “all-sky” scene would be recreated on the dome as it was in real life.

If you are with a planetarium, contact me if you’d like to get aurora clips.

Our second group of aurora tourists has arrived today at the Churchill Northern Studies Centre, and the weather is warming to a high of -20° C. Balmy!

We’re hoping for more fine displays, though the space weather forecast calls for a quiet magnetic field in the next few days.

June 1, 2014June 1, 2014

Rainbow at Sunset

As the setting Sun broke through clouds it created a rainbow over my backyard.

I see lots of fine sky phenomena right from my back deck. Such was the case last evening as a storm retreated east as they typically do. Clearing skies in the west allowed the Sun to shine through, the perfect combination for a rainbow.

For the main image above I shot the double rainbow with the ultra-wide 14mm Rokinon lens …

… and also with the 8mm Sigma fish-eye lens for this image. It’s angled to be suitable for re-projection in a tilt-dome planetarium theatre.

We’re into stormy spring weather here in Alberta, so there will be many more rainbows to follow the dark clouds. Let’s hope for no more floods like last June.

April 11, 2014April 11, 2014

The Galactic Archway of the Southern Sky

The southern Milky Way arches across the sky, with the centre of the Galaxy overhead at dawn.

This was the sky at 4:30 this morning, as Venus rose in the east (to the right) amid the zodiacal light, and with the Milky Way soaring overhead. This image is a 360° panorama of the scene, with the zenith, the overhead point, at the top centre of the frame.

The location is the Two Styx Cabins, on the border of New England National Park in New South Wales, Australia. The cabin with the light on (I left it on on purpose for the photo) is where I stayed for two nights in splendid isolation.

The panorama is a stitch of 6 frames shot with an 8mm fish-eye lens, each 1-minute exposures on an untracked tripod. I used the PTGui software program to assemble the pan.

Below is an alternative rendering, in spherical format, to create the more classic “fish-eye” view, but one extending well below the horizon. So this is not one image but a stitch of six.

In this version you can more readily see the spectacle of the Milky Way at dawn in the southern hemisphere autumn months, with the bulge of the galactic core directly overhead as seen from this latitude of 30° south. It is a wonderful sight.

This is my last view of it for this trip. Till next year!

February 13, 2014February 13, 2014

Rings Around the Moon

An ice crystal halo surrounds the Moon while a jet contrail crosses the sky.

On our last nights earlier this week at the Churchill Northern Studies Centre we had a bright gibbous Moon in our sky (as did everyone in the world!). We also had high-altitude clouds filled with ice crystals, the source of the “ring around the Moon” effect. This is a lunar halo, created by moonlight shining through six-sided ice crystals. This halo exhibits rainbow-like colours as well.

But this night, conditions were also ideal for seeing the contrails from jets flying overhead on polar routes from Europe to North America. In the main image above, you can see the jet departing to the west at lower right. Its high-altitude contrail is casting a dark shadow onto the lower cloud deck.

This view, taken earlier in the evening shows a more pronounced lunar halo with a horizon-to-horizon contrail shooting straight across the Moon and also casting a shadow.

I used an 8mm fish-eye lens to capture this 360° image of the entire sky. I was able to shoot this image in shirt-sleeve comfort through the rooftop plexiglas viewing dome at the Centre.

In this image, taken outside at -25° C, the sky is clearer but still contains enough ice crystal cloud to create a bright lunar halo. When I took this image on February 9 the Moon was to the right of bright star-like Jupiter, and in the middle of the winter stars and constellations, such as Orion just below the Moon.

Lunar haloes can be seen at any season. On any night with a nearly Full Moon embedded in high haze, look up!

February 8, 2014February 9, 2014

Waves of Northern Lights in Time-Lapse

Watch waves of aurora wash over the sky rising out of the west to swirl overhead.

This was the spectacle we saw Friday night at the Churchill Northern Studies Centre, as the northern lights filled our sky. I set up my camera on the east side of the main building, out of the bitterly cold west wind. The fish-eye lens is aimed west but its view takes in most of the sky.

The bright object at lower left is the Moon.

The still image above is a frame from the 349-frame time-lapse movie below.

Each frame is a 7-second exposure at f/3.5 and ISO 1250. The interval is 1 second.

The movie covers about 45 minutes of time, compressed into 30 seconds. It shows the aurora peaking in intensity, then fading out behind the ever-present thin cloud drifting through all night.

What amazes me are the waves and loops of auroral curtains that come at us from the west (bottom behind the building) then swirl around the zenith overhead. They move off to the east and north at the top of the frame.

Even watching this in real-time the scene was astonishing. The curtains rippled so quickly, forming and reforming over the sky, you didn’t know where to look. As the image above shows, people just stood amazed.

P.S.: You can view a better-grade version of the movie at my Flickr site.

February 3, 2014

Aurora Shining Through the Clouds

Tonight the aurora shone so brightly for a time it was visible through the cloud.

Here at the Churchill Northern Studies Centre we’ve been battling clouds all week. But on several nights the clouds have cleared for 30 minutes or more, enough to give us glimpses of the aurora and stars. Tonight, February 2/3, the clouds never did clear away enough for a great view. This was as good as it got, with the Northern Lights shining through haze and cloud but nevertheless filling the sky.

Remarkably, this was on a night when the usual indicators of auroral activity were registering all quiet. This shows the benefit of traveling north to stand right under the auroral oval, the zone of maximum activity. In this case I’m at 58° North, in Churchill, Manitoba. Even on a quiet night the Churchill sky can be filled with curtains of dancing colours.

August 23, 2012August 23, 2012

Horizon to Horizon Milky Way

The view doesn’t get any wider than this. This fish-eye image takes in the entire night sky and summer Milky Way.

I shot this last weekend at the Saskatchewan Summer Star Party in Cypress Hills. Red lights of observers streak along the horizon around the perimeter of the circular image. At centre is the zenith, the point in the sky straight overhead.

The sky was very dark, but the sky close to the horizon is tinted with the faint glows of aurora and airglow.

The Milky Way is the main feature of the summer sky, here stretching from Sagittarius in the south at bottom to Perseus at top in the north. Wide shots like this really put the giant lanes of dust into proper context; you can see their full structure and faint tendrils extending well off the Milky Way band.

For these fish-eye shots (suitable for projection in a planetarium) I used a Sigma 8mm fish-eye lens and a full-frame Canon 5D MkII camera. This is a stack of five 5-minute exposures, all tracked. The landscape is from just one of the images, to minimize blurring of the ground.

May 2, 2011May 2, 2011

The Milky Way from Chile

This was the Milky Way as it appeared toward the end of a long night of non-stop shooting from Chile. The centre of the Galaxy lies directly overhead and the Milky Way stretches from horizon to horizon. This is one of the sky’s greatest sights, and this is an ideal time of year to see it. But only if you are in the magic latitude zone of 20° to 30° south.

In this shot, another skyglow stretches up from the eastern horizon at left – that’s the Zodiacal Light, so obvious from this latitude. It’s sunlight reflected off comet dust in the inner solar system, and heralds the coming dawn twilight.

My tracking platform – the device that allows a camera to follow the sky for a time exposure – is at lower right, with a second camera taking telephoto lens shots of star clusters in the Milky Way.

I took this shot with the Sigma 8mm fish-eye lens and the Canon 5D MkII camera that was on a fixed tripod – it was not tracking the sky. But the 45-second exposure at ISO 3200 was enough to bring out the Milky Way in all its glory. This frame is one of 660 or so that make up (or will once I assemble it) a time-lapse movie of the Milky Way turning about the pole and rising through the night. The fish-eye format makes it suitable for projection in a planetarium dome.