The Rising of the Harvest Moon

On two clear evenings the Harvest Moon rose red and and large over the Alberta prairie.

I present a short music video (linked to below) of time-lapse sequences of the Harvest Moon of 2020 rising. I shot the sequences through a small telescope to zoom in on the Moon’s disk as it rose over the flat horizon of the prairie near where I live. I love being able to see the horizon!

Note the effects of atmospheric refraction squishing the Moon’s disk close to the horizon. The Moon becomes more normal and spherical as it rose higher.

People sometimes think the refraction effect is responsible for making the Full Moon appear large on the horizon, but the atmosphere has nothing to do with it. The effect is strictly an optical illusion. The Moon is no bigger on the horizon than when it is higher in the sky.

The photo below shows a composite of images taken September 30, 2020.

The rising of the nearly Full Moon, the Harvest Moon of 2020, on September 30, from a site near home in Alberta, looking just south of due east this night. Refraction distorts the disk and atmospheric absorption reddens the disk toward the horizon. This is a multiple exposure composite of 6 images with the Canon 6D MkII through the 80mm A&M apo refractor at f/6 without field flattener. Taken as part of a time-lapse sequence with images every 2 seconds. The frames for this blend were taken 2 minutes apart, so selected from every 60 frames out of the sequence. All were at 1/8 second at ISO 100. Images stacked in Photoshop and blended with Lighten mode. The ground comes from the first image.

Note in the image below, from October 1, how much redder the Moon appears. That’s the effect of atmospheric absorption, in this case from dust and smoke in the air dimming and reddening the Moon (the same happens to the rising or setting Sun). At times this evening it looked like the Moon was in a total eclipse.

The Harvest Moon (the Full Moon of October 1, 2020) rising almost due east at the end of a country road in southern Alberta, near home. The horizon was smoky or dusty, so the Moon was very red as it rose, and looking almost like a totally eclipsed Moon. This is a blend of 6 exposures, all 1/2-second with the A&M 80mm f/6 apo refractor (for 480mm focal length) and Canon 6D MkII at ISO 400, taken as part of a 460-frame time-lapse sequence, with shots every 2 seconds. For this composite I choose 6 images at 2-minute intervals, so the Moon rose its own diameter between frames. The ground comes from the first image in the sequence when the lighting was brightest. The Moon rose at 7:35 pm this night, about 30 minutes after sunset. A mild Orton glow effect added to the ground with Luminar 4.

Below is the link to the time-lapse music video on Vimeo. It is in 4K. I used Adobe Camera Raw, Adobe Bridge, and LRTimelapse to process the component images as raw files for the time-lapse sequences, as per tutorials in my Nightscape and Time-Lapse ebook, above.

Thanks for looking! Clear skies!

— Alan / © 2020

The Great Transit Expedition of 2019

Blog Title

On November 11, I traveled to the near-flung corners of my backyard to observe the rare transit of Mercury across the Sun.

History is replete with tales of astronomers traveling to the far corners of the Earth to watch dark objects pass in front of the Sun — the Moon in eclipses, and Mercury and Venus in transits.

On November 11, to take in the last transit of Mercury until 2032, I had planned a trip to a location more likely to have clear skies in November than at home. A 3-day drive to southern Arizona was the plan.

But to attend to work and priorities at home I cancelled my plans. Instead, I decided to stay home and take my chances with the Alberta weather, perhaps making a run for it a day’s drive away if needed to chase into clear skies.

Transit of Mercury Selfie with Sun

As it turned out, none of that was necessary. The forecast for clear, if cold, skies held true and we could not have had a finer day for the transit. Even the -20° C temperatures were no problem, with no wind, and of course sunshine!

Plus being only steps from home and a warming coffee helped!

As it turned out, the site in Arizona I had booked to stay was clouded out for the entire event. So I was happy with my decision!

For my site in Alberta, as for all of western North America, the Sun rose with the transit in progress. But as soon as the Sun cleared the horizon there was Mercury, as a small, if fuzzy, black dot on the Sun.

Low Sun with Mercury in Transit

As the Sun rose the view became sharper, and was remarkable indeed — of a jet black dot of a tiny planet silhouetted on the Sun.

The Transit of Mercury Across the Sun (10 am MST)

I shot through two telescopes, my 4-inch and 5-inch refractors, both equipped with solar filters of course. I viewed through two other telescopes, for white-light and hydrogen-alpha filtered views.

I was able to follow the transit for three hours, for a little more than half the transit, until Mercury exited the Sun just after 11 a.m. MST. The view below is from moments before Mercury’s exit, or “egress.”

The Transit of Mercury Across the Sun (11 am MST)

I shot still frames every 15 seconds with each of the two cameras and telescopes, for a time-lapse, plus I shot real-time videos.

Mercury at Mid-Transit (November 11, 2019)

At this transit Mercury passed closer to the centre of the Sun’s disk than it will for any other transit in the 21st century, making this event all the more remarkable. That point is recorded above, from a shot taken at 8:19 a.m. MST.

Stacking a selection of the time-lapse frames, ones taken 1-minute intervals, produced this composite of the transit, from just before mid-transit until Mercury’s egress.

Transit of Mercury Composite Across the Sun v2

I assembled all the best images and 4K videos together into a movie, which I narrated live at the telescope as the transit was happening. I hope this provides a sense of what it was like to view this rare event.

The Transit of Mercury from Alan Dyer on Vimeo.

We won’t see another until 2032, but not from North America. The next transit of Mercury viewable from here at home is not until 2049! This was likely my last transit, certainly for a while!

Transit of Mercury Trophy Shot

This was my trophy shot! Bagged the transit!

P.S.: For my video of the previous transit of Mercury in May 2016, see my blog post which includes a similar compilation video.

P.P.S.: And for tech details on the images and videos in this blog, please click through to Vimeo and the video description I have there of cameras, scopes, and settings.

Clear skies!

Alan, November 17, 2019 / © 2019 Alan Dyer /


Top 10 Tips for Practicing for the Eclipse

Total Eclipse from Chile

I present suggestions for how to ensure everything under your control will go well on eclipse day. The secret is: Practice, Practice, Practice!

The techniques I suggest practicing are outlined in my previous blog, Ten Tips for the Solar Eclipse. It’s prerequisite reading.

However, while you can read all about how to shoot the eclipse, nothing beats actually shooting to ensure success. But how do you do that, when there’s only one eclipse?

Here are my “Top 10” suggestions:

Total Eclipse of the Sun from the Atlantic (Nov 3, 2013)
Total eclipse of the Sun, November 3, 2013 as seen from the middle of the Atlantic Ocean, from the Star Flyer sailing ship. I took this with a Canon 5D MkII and 16-35mm lens at 19mm for 1/40s at f/2.8 and ISO 800 on a heavily rolling ship.

Wide-Angle Shots – Shoot a Twilight Scene

The simplest way to shoot the eclipse is to employ a camera with a wide lens running on auto exposure to capture the changing sky colors and scene brightness.

  1. Auto Exposure Check in Twilight

    If you intend to shoot wide-angle shots of the eclipse sky and scene below, with anything from a mobile phone to a DSLR, practice shooting a time-lapse sequence or a movie under twilight lighting. Does your camera expose properly when set to Auto Exposure? If you are using a phone camera, does it have any issues focusing on the sky? How big a file does a movie create? 


PRACTICE2-Voyager Alt-Az Mount

With Telephotos and Telescopes – Shoot the Filtered Sun

The toughest techniques involve using long lenses and telescopes to frame the eclipsed Sun up close. They need lots of practice. 

  1. Framing and Focusing

    You’ll need to have your safe and approved solar filter purchased (don’t wait!) that you intend to use over your lens or telescope. With the filter in place, simply practice aiming your lens or telescope at the Sun at midday. It’s not as easy as you think! Then practice using Live View to manually focus on the edge of the Sun or on a sunspot. Can you get consistently sharp images?


Partial Solar Eclipse in Cloud #1 (Oct 23, 2014)
The partial eclipse of the Sun, October 23, 2014, shot through thin cloud, but that makes for a more interesting photo than one in a clear sky. Despite the cloud, this was still shot through a Mylar filter, on the front of telescope with 450mm focal length, using the Canon 60Da for 1/25 sec exposure at ISO 100.

  1. Exposure Times

Exposures of the filtered Sun will be the same as during the partial phases, barring cloud or haze, as above, that can lengthen exposure times. Otherwise, only during the thin crescent phases will shutter speeds need to be 2 to 3 stops (or EV steps) longer than for a normal Sun.


PRACTICE4-Kendrick and Seymour Filters
Solar filters that clamp around the front of lenses are easier to remove than ones that screw onto lenses. They will bind and get stuck!

  1. Filter Removal

With the camera aimed away from the Sun (very important!), perhaps at a distant landscape feature, practice removing the filter quickly. Can you do it without jarring the camera and bumping it off target? Perhaps try this on the Moon at night as well, as it’s important to also test this with the camera and tripod aimed up high.


PRACTICE5-Nikon Screens on 80mm
Articulated LCD screens are a great aid for framing and viewing the eclipse in Live View when the camera is aimed up high, as it will be!

  1. Ease of Use

With the Sun up high at midday (as it will be during the eclipse from most sites), check that you can still look through, focus, and operate the camera easily. Can you read screens in the bright daylight? What about once it gets darker, as in twilight, which is how dark it will get during totality.


PRACTICE6-Sun Motion Composite
The east-to-west motion of the sky will carry the Sun its own diameter across the frame during totality, making consistent framing an issue with very long lenses and telescopes.

  1. Sun Motion

If you are using an untracked tripod, check how much the Sun moves across your camera frame during several minutes. For videos you might make use of that motion. For still shots, you’ll want to ensure the Sun doesn’t move too far off center.


PRACTICE7-HEQ5 with 80mm Mount N
An equatorial mount like this is great but needs to be at least roughly polar aligned to be useful.

  1. Aligning Tracking Mounts

If you plan to use a motorized equatorial mount capable of tracking the sky, “Plan A” might be to set it up the night before so it can be precisely polar aligned. But the reality is that you might need to move on eclipse morning. To prepare for that prospect, practice roughly polar aligning your mount during the day to see how accurate its tracking is over several minutes. Do that by leveling the mount, setting it to your site’s latitude, and aiming the polar axis as close as you can to due and true north. You don’t need precise polar alignment to gain the benefits of a tracking mount – it keeps the Sun centered – for the few minutes of totality.


The March Mini-Moon
The Full Moon is the same brightness as the Sun’s inner corona.

Telephotos and Telescopes – Shoot Full Moon Closeups 

  1. Exposure Check

Shoot the Full Moon around July 8 or August 7. If you intend to use Auto Exposure during totality, check how well it works on the Full Moon. It’s the same brightness as the inner corona of the Sun, though the Moon occupies a larger portion of the frame and covers more metering sensor points. This is another chance to check your focusing skill.


Impending Occultation of Beta Capricorni
The crescent Moon has a huge range in brightness and serves as a good test object. Remember, the Moon is the same size as the Sun. That’s why we get eclipses!

Telescopes and Telescopes – Shoot Crescent Moon Closeups

  1. Exposure Check

Shoot the waxing crescent moon in the evening sky during the last week of June and again in the last week of July. Again, test Auto Exposure with your camera in still or movie mode (if you intend to shoot video) to see how well the camera behaves on a subject with a large range in brightness. Or step through a range of exposures manually, from short for the bright sunlit crescent, to long for the dark portion of the Moon lit by Earthshine. It’s important to run through your range of settings quickly, just as you would during the two minutes of totality. But not too quickly, as you might introduce vibration. So …


PRACTICE10-2006 Libya-Short
Good focus matters for recording the fine prominences and sharp edge of the Moon.

  1. Sharpness Check

In the resulting images, check for blurring from vibration (from you handling the camera), from wind, and from the sky’s east-to-west motion moving the Moon across the frame, during typical exposures of 1 second or less.


By practicing, you’ll be much better prepared for the surprises that eclipse day inevitably bring. Always have a less ambitious “Plan B” for shooting the eclipse simply and quickly should a last-minute move be needed.

However, may I recommend …

How to Photograph the Solar Eclipse
My 295-page ebook on photographing the August 21 total eclipse of the Sun is now available. See It covers all techniques, for both stills, time-lapses, and video, from basic to advanced, plus a chapter on image processing. And a chapter on What Can Go Wrong?! The web page has all the details on content, and links to order the book from Apple iBooks Store (for the best image quality and navigation) or as a PDF for all other devices and platforms.

For much more detailed advice on shooting options and techniques, and for step-by-step tutorials on processing eclipse images, see my 295-page eBook on the subject, available as an iBook for Apple devices and as a PDF for all computers and tablets.

Check it out at my website page

Thanks and clear skies on August 21!

— Alan, June 24, 2017 / © 2017 Alan Dyer /


Transit of Mercury

Transit of Mercury near Sunrise

On May 9, a last-minute chase into clear skies netted me a view of the rare transit of Mercury across the Sun.

The forecast called for typical transit weather – clear the day before, and clear the day after. But the day of the transit of Mercury? Hopeless at home in Alberta, unless I chanced the prospects of some clearing forecast for central Alberta.

As the satellite image below, for 8:30 a.m. MDT on May 9, shows, that clearing did materialize. But I headed west, as far west as I needed to go to be assured of clear skies – to central BC. Kamloops in fact.


I stayed at the Alpine Motel, got a great room as the end, and set up in the parking lot away from traffic. Not the most photogenic of observing sites, but I was happy! I had my clear skies!


I set up two telescopes, above: a 130mm refractor to shoot through, and an 80mm refractor to look through. Both with dense solar filters!

Both worked great. However, low cloud prevented me seeing the Sun as soon as it cleared the eastern hills. So this was my first good look, below, at the transit as the Sun rose above the clouds.

Transit of Mercury near Sunrise
The May 9, 2016 transit of Mercury taken about half an hour after sunrise, as the Sun emerged from low horizon cloud. Taken from Kamloops, British Columbia, where the transit was well underway at sunrise. Mercury appears as the circular dot at lower left, with a sunpot group above centre. I shot this with the 130mm Astro-Physics refractor at f/6 prime focus with the Canon 60Da camera at ISO 100. Shot through a Kendrick white light solar filter. The low atltitude added much of the yellow colouration.

There it was – the fabled “little black spot on the Sun today.” Mercury is the dot at lower left, with a sunspot group at upper right. This was the first transit of Mercury since November 8, 2006. We see only about 13 Mercury transits a century, so in a lifetime of stargazing (the Sun is a star!) even the most avid amateur astronomer might see only a handful. This was only my third transit of Mercury.

Transit of Mercury in Clouds
The May 9, 2016 transit of Mercury taken about 45 minutes after sunrise, as the Sun emerged from low horizon cloud. I shot this with the 130mm Astro-Physics refractor at f/6 prime focus with the Canon 60Da camera at ISO 100. Shot through a Kendrick white light solar filter.

This was the view, above, a little later, as the Sun entered more assuredly clear skies. From about 7 a.m. PDT on, the Sun was in the clear most of the morning, with just occasional puffy clouds intervening now and then.

I shot still images every 30 seconds, to eventually turn into a time-lapse movie (after a ton of work hand registering hundreds of frames!).

But for now, I’ll be content with this composite of 40 frames, below, taken at 7-minute intervals. It shows the progress of Mercury across the Sun over the last 4.5 hours or so of the event, until egress at 11:38 a.m. PDT.

This motion is due to Mercury’s movement around the Sun. A transit is one of the few times you can easily see a planet actually orbiting the Sun.

Transit of Mercury (May 9, 2016) Composite with Arrow
For all images I used the 130mm f/6 Astro-Physics refractor with a 2X Barlow for an effective focal length of 1560mm and the Canon 60Da camera (at ISO 100) to yield an image size with the Sun just filling the frame. Exposures were 1/250th second through a Kendrick white light Mylar filter. Yellow colouration of the solar disk added in processing.

In this composite, the disks of Mercury are not all perfect dots. The wobbly seeing conditions distorted the images from frame to frame. But I used the actual images taken at that moment, rather than clone some perfect image across the disk to simulate the path.

To wrap up, here’s Mercury Transit: The Movie! I shot several HD and zoomed-in “crop mode” movies at the beginning of the transit and again at the final egress. Commentary is from me talking live into the camera mic as I was shooting the clips. Background noise is courtesy Pacific Drive and the Trans-Canada Highway!

Enjoy, and do enlarge to HD and full-screen for the best look.


The next transit of Mercury is November 11, 2019. If you are hoping for a transit of Venus, good luck. The next is not until December 10, 2117!

– Alan, May 15, 2016 / © 2016 Alan Dyer /


Relaunching Stargazing in Barbados

Observatory Viewing in Barbados (Nov 16, 2013) #1

Barbados is soon to have a new state-of-the-art public observatory for promoting astronomy.

On Saturday night, November 16, I was fortunate and privileged to be the guest speaker at the first event at the newly refurbished Harry Bayley Observatory in Bridgetown, Barbados. A grant from an educational foundation in the UK has allowed the Barbados Astronomical Society to renew the aging 50-year-old facility with a fresh new interior, and all the high-tech fittings of a modern public observatory.

A new dome was lifted into place on top of the 3-storey structure earlier in the week, and the painting and interior finishing was completed just a day or two before my talk, in time for a public RSVP event Saturday night.

Observatory Interior Panorama #1

I gave a talk on The Amazing Sky, showing images and movies from the November 3 total eclipse, among many other photos of the sights anyone can see in the day and night sky. I gave the same talk twice, to two packed houses of 40 people per session in the main floor meeting room/lecture hall. A wonderful spread of local food and drink was served upstairs.

Lots of work remains to complete the refurbishment but the facility was in good enough shape to host a public event. The official opening is in January.

Observatory Viewing in Barbados (Nov 16, 2013) #3

A new Meade 16-inch telescope on a Software Bisque MX2 mount is on its way for installation later this year, equipped with the latest robotic control and digital cameras for public viewing. A hydrogen-alpha solar telescope will also be part of the arsenal of equipment.

This night, members set up a portable Celestron 8-inch telescope outside for viewing the Moon and Jupiter. In contrast to viewing at home at this time of year, observing from 13° North latitude was in shorts and shirt-sleeves.

It was a terrific evening and I’m pleased to have been part of the relaunching of the Observatory and astronomy activities on the island. Many thanks go to my host on the island, Greg Merrick, for making the evening – and my stay this week – possible.

– Alan, November 17, 2013 / © 2013 Alan Dyer

Aurora at the Observatory

Aurora over Calgary from RAO (May 25, 2013)

A low aurora appears in the city skyglow and bright moonlight at the local observatory. 

After several days of rain, skies cleared beautifully for a Saturday night star party for the public at the local university observatory, the Rothney Astrophysical Observatory, southwest of Calgary.

The evening was capped off by the appearance, as expected, of an auroral arc to the north. Despite the light from the nearly Full Moon and urban sky glow to the north, the aurora managed to compete and put on a show for a few minutes before fading.

RAO Open House (May 25, 2013) #10

RAO Open House (May 25, 2013) #13

About 100 people attended the evening, and were treated to views of Saturn, shining in the south near Spica. Unfortunately, clouds to the west over the mountains never cleared away enough to allow us views, and me photos, of the triple-planet conjunction of Mercury, Venus and Jupiter. Still, a good time was had by all.

– Alan, May 26, 2013 / © 2013 Alan Dyer