methods – The Amazing Sky

February 21, 2024February 21, 2024

Tutorials and Tips for the Solar Eclipse

As eclipse day approaches here are some tips and video tutorials from me about how best to capture the total eclipse of April 8, 2024.

There are many ways to capture great images and movies of a total eclipse of the Sun. I outline them all in great detail in my 380-page ebook How to Capture the Solar Eclipses, linked to at right.

Originally published in June 2023, I revised the ebook following the October 14, 2023 annular eclipse of the Sun to include “lessons learned at the eclipse,” and some processing tutorials on assembling annular eclipse composites. I’ve also added new content on using software to control cameras and updated information about solar filters.

Brief Tips and Techniques

The August 21, 2017 total solar eclipse over the Grand Tetons as seen from the Teton Valley in Idaho, near Driggs. With the Canon 6D and 14mm SP Rokinon lens at f/2.5 for 1/10 second at ISO 100.

My breakdown of recommend methods, in order from simplest to most complex, and with increasing demands on your time, is generally this:

Use a Phone Camera for a Movie. While they can be used for a quick handheld grab shot during totality, a better method is to place a phone on a tripod using a clamp of some kind. Then a few minutes before totality aim and frame the scene, with no filter over the camera lens. Start it in movie mode to record video of the eclipse and sky changes, and the excited sounds of your group! Just remember to stop the video shortly after the end of totality and aim the phone away from the Sun. Never leave any unfiltered camera aimed at the Sun for a long time.
Shoot a Wide-Angle Time-Lapse. Using a DSLR or mirrorless camera and a wide-angle lens (it might need to be as wide as a 14mm at sites in Mexico and the southern U.S.) aim and frame the camera to include the Sun and landscape below. Focus the lens! And leave it on manual focus. But put the camera into Auto-Exposure Aperture Priority (Av) with wide-area metering and with it set to underexpose by -1 EV Exposure Compensation. With the camera at ISO 100 or 200, use either its internal intervalometer (if it has one) or an external intervalometer to take frames once per second. Start the sequence with no filter on the lens a few minutes before totality. Let it run on its own until a few minutes after totality. The result is hundreds of frames you can turn into a time-lapse movie of the lunar shadow approaching and receding, and of the changes in sky colours. Or you can extract single frames at key points to process individually, as I did for the image above from August 2017. The advantage, as with the phone camera movie method, is that the camera, once going, requires no further attention. You can enjoy the eclipse!
Shoot a Telephoto Video. Use a 300mm to 500mm lens on a DSLR or mirrorless camera to shoot a real-time close-up video of the eclipse. Start the video a minute or two before totality with the Sun positioned to the left of frame centre and with a solar filter over the lens. Use a slow ISO, the lens wide open (typically f/4 to f/5.6) and the camera on Auto-Exposure Aperture Priority (Av). Just be careful to focus precisely on the filtered Sun before starting the video. Poor focus is what spoils most eclipse images, not poor exposure. Just before totality (about 30 seconds prior to Second Contact) remove the filter. The auto-exposure will compensate and provide a proper exposure for the rest of totality. Just let the camera run and the Sun drift across the frame from left to right. Just remember to replace the filter, or cap the lens, and stop the video shortly (~30 seconds) after totality and Third Contact. The video will capture the diamond rings and a well-exposed corona. Vary the exposure compensation during totality if you wish, but that involves more work at the camera. Otherwise, you can just let the camera run. But, as I illustrate in my ebook, it’s important to plan and place the Sun correctly to begin with (using a planetarium app to plan the sequence), so it does not drift off the frame or close to the edge.
Shoot Telephoto Close-Up Stills. Use the same type of gear to shoot still images. While you could shoot stills on Auto-Exposure, it’s better to shoot still images over a range of exposures, from very short (~1/1000 second) for the diamond rings and prominences, to long (~1 second) for the outer corona. No one exposure can capture all that the eye can see during totality. This takes more work at the camera, and with the camera on a static tripod you might have to re-centre the Sun during totality, another thing to fuss with and where things can go wrong. Using the camera’s Auto-Bracketing mode can help automate the shooting, allowing the camera to automatically shoot a set of 7 to 9 exposures at say, one-stop increments in quick succession with just one press of the shutter button (by using the self-timer set to 2 seconds).
Shoot with a Telescope on a Tracking Mount. Telescopes (I like 60mm- to 100mm-aperture apochromatic refractors) allow longer focal lengths, though I would advise against shooting with any optics longer than 600mm to 800mm, so the image frames the corona well. Use similar settings as above, but with the telescope (or a telephoto lens) on a tracking mount to turn from east to west at the same rate as the sky moves. That will ensure the Sun stays centred on its own, provided you have at least roughly polar aligned the mount. (Set it to your site’s latitude and aim the polar axis as due north as you can determine from compass apps.)

Those are brief summaries of the methods I recommend, as they are ones I’ve used with success in the past and plan to use on April 8. My ebook contains much more information, and answers to most of the “But what about using ….?” questions. And I provide lots of information on what can go wrong! Some learned the hard way over 16 previous total solar eclipses.

Video Tutorials

For a video tutorial, check out the webinar I conducted as part of the Kalamazoo Astronomical Society’s excellent Eclipse Series here on YouTube. It is about a 1-hour presentation, plus with lots of Q&A at the end.

KAS Eclipse Series — Part 1: Shooting

Of course, once you have all your images, you need to process them. My ebook’s biggest chapter (at 80 pages) is the one on processing still images and time-lapses.

So, a month after I presented the above webinar on Shooting, I was back on-line again for a follow-up webinar on Processing. You can view that KAS Eclipse Series tutorial here on YouTube.

KAS Eclipse Series — Part 2: Processing

I cover processing single wide-angle images, a wide-angle time-lapse series, single-image close-ups, and blending multiple exposure composites.

A month later, I presented a further webinar to the Astronomical League as part of their AL Live series, again on shooting the eclipse, but now with an emphasis on techniques amateur astronomers and astrophotographers with typical telescope gear might use.

You can view the AL Live webinar here. My presentation begins at the 44-minute mark.

AL Live Webinar — Scrub ahead to 44 minutes

I emphasized that the kinds of gear astrophotographers use these days with great success on deep-sky objects might not work well for the eclipse. The specialized cameras, and software used to control them, are just not designed for the demands of a total eclipse, where exposures have to range over a wide array of settings and change very quickly. Images have to be taken and recorded in rapid succession.

I suspect a lot of ambitious and overly-confident astrophotographers will come away from the 2024 eclipse disappointed — and what’s worse, without having seen the eclipse because they were too wrapped up looking at laptop screens trying to get their high-tech gear working.

Practice, Practice, Practice

In these webinars and in my ebook, my common theme is the importance of practicing.

Don’t assume something will work. Practice with the gear you intend to use, on the Sun now (with proper filters) and on the Moon. The crescent Moon, with dim Earthshine lighting the lunar night side, is a great practice target because of its wide range of brightness. And it moves like the Sun will, to check maximum exposure times vs. image blurring from motion.

Practice with your tripod or mount aimed to the altitude and location in the sky where the Sun will be from the site you have chosen. Set a tracking mount to the latitude you will be at to be sure it will aim at and track the Sun without issues. Some telescope mounts stop tracking when they reach due south, exactly where the Sun will be at totality from southern sites. That’s a nasty surprise you do not want to encounter on eclipse day.

All this and much more is covered in my ebook, available for Apple Books and as a PDF for all platforms here from my website at https://www.amazingsky.com/EclipseBook

Good luck on eclipse day!

— Alan, February 21, 2024

September 4, 2023September 5, 2023

Testing for the Annular Solar Eclipse

With the October 14, 2023 annular eclipse of the Sun only weeks or days away, it’s time to test your equipment, to ensure success on eclipse day.

On October 14 everyone in North America, Central America, and much of South America can see an eclipse of the Sun, as shown in the map below, courtesy GreatAmericanEclipse.com. The closer you are to the “path of annularity” drawn in yellow here, the more of the Sun you see covered by the Moon.

Eclipse map showing area of visibility of the October 14 eclipse courtesy GreatAmericanEclipse.com

However, for the best experience, plan to be in the central path of the Moon’s shadow. In North America, as shown in the map below, that path crosses the western states, passing over the scenic landscapes of the American southwest.

Those in the main path will see an annular eclipse – the Moon will travel across the center of the Sun’s disk, but won’t be large enough to completely cover the Sun. The result, as shown below, is that the Sun will be reduced to a thin ring or “annulus” of light at mid-eclipse, but only for a few minutes.

For details of when the eclipse occurs and how long the eclipse lasts at your site, see the interactive map at Fred Espenak’s site at https://www.eclipsewise.com/solar/SEgmapx/2001-2100/SE2023Oct14Agmapx.html

GEAR AND FILTERS

The May 10, 1994 annular eclipse of the Sun, with a trio of eclipse rigs.

To view or photograph the annular eclipse well, you need to use a long telephoto lens or a telescope. A focal length of 400mm or longer is required to make the Sun’s and Moon’s disks large enough to show detail well.

As I show above, the lens or telescope can be on a solid tripod, or on an untracked alt-azimuth telescope mount, or on a mount that can track the sky, such as the equatorial mount on the right above. All will work fine, as exposures will always be short, just a fraction of a second.

I go into the many options for photographing the eclipse in my ebook, linked to at right. It contains thorough tutorials on how to shoot the eclipses in 2023 and 2024. In this blog I’m focusing on extolling the need to practice now, with whatever gear you own and intend to use for the eclipse.

An array of solar filers, for unaided eyes, lenses and telescopes

No matter what optics you plan to use, they must be equipped with a safe solar filter mounted over the front of the optics. For the October 14 eclipse, even from sites in the path of annularity, a filter must be used at all times. It will never be safe to look at or shoot the Sun without a filter.

And it must be a filter dense enough and designed for the purpose of aiming at the Sun. Do not use stacked neutral density filters or other jury-rigged arrangements, as other filters can transmit ultraviolet or infrared light that can still damage eyes and cameras.

If you do not have a proper filter for your lens or telescope, get one now. Order from reputable suppliers such as AstroZap, Baader Planetarium, Kendrick Astro Instruments, Seymour Solar, Thousand Oaks Optical, or from the makers of telescopes and their dealers.

The eyeglass or handheld style of solar filters are good for unaided eye views, and most are made by American Paper Optics or Rainbow Symphony. A list of recommended filter suppliers is available at the American Astronomical Society’s eclipse website at https://eclipse.aas.org/eye-safety. In addition, many astronomy clubs, planetariums and science centers will offer safe eyeglass-style filters they purchased in bulk from one of the suppliers above.

However, for photography through a lens or telescope you need a filter that either screws onto the lens or clamps over the telescope, as I show below.

Comparing different types of telescope filters – the Baader Mylar worked best in this test.

In my testing, I’ve found that the aluminized Mylar® (or polyethylene) type of filter – one that looks like a silvery sheet – provides the best sharpness and contrast, despite the wrinkles. The most popular type is made by Baader Planetarium, and sold by them or by other dealers and resellers.

While metal-coated glass filters also work very well, in recent years they have become hard to find, with past suppliers of glass filters switching to black polymer plastic material. While safe and good for naked-eye views, I’ve found the image through black polymer filters can be soft and surrounded by lots of light scatter when used for photography at long focal lengths.

TESTING, TESTING!

An eclipse rig under test, with dual scopes for shooting and looking

Once properly equipped, test your setup as soon as possible on the Sun. In the rig above I have piggybacked a smaller telescope onto the larger telescope, both with filters, the latter to shoot through while I look through the smaller scope, good for watching the few minutes of annularity.

The key things to test for are:

Finding the Sun (not as easy as you might think!)
Focusing on the Sun (also critical and can be tough – focus on the edge or on sunspots)
Checking for any focus shift over a couple of hours time
Determining the correct exposures with your filter
Checking for any vibration that can blur the image
Operating your camera to change settings, without vibration
Checking to see how long batteries will last
Seeing how much the Sun moves across the frame during a few minutes time
Following the Sun or keeping it centered
Making a checklist of the gear you need on eclipse day, plus any backups such as a spare battery, and tools for last-minute fixes or adjustments.

The filters from Kendrick Astro Instruments have a handy Sun finder attachment.

You want to test how solid your setup is when aimed up. Your super-telephoto lens and tripod that work great for birds and wildlife might not be as well-suited as you thought when aimed high at the Sun. Best to find out now about any shortcomings in your gear.

A series of images with an 80mm refractor and Kendrick Mylar filter shows a range from under to over-exposed.

Run through a set of exposures to see what produces the best result with your optics and filter. Even with the October 14 eclipse underway, the Sun will be a similar brightness as it is on any normal day.

At best, on eclipse day you might wish to shoot a bracketed set of exposures throughout the eclipse, perhaps a frame taken at your pre-determined “best” exposure, and two others: at one stop and two stops overexposed, to account for the slightly dimmer solar disk when it is mostly covered by the Moon in a deep partial or annular phase.

Alter exposures by changing shutter speeds, not aperture or ISO. Keep the ISO speed low, and the aperture either wide open or at some middle setting such as f/5.6 for the sharpest images.

But also check what exposures might be needed when shooting the Sun through thin clouds. Any cloud or haze will require longer exposures. And you might need to change shutter speeds quickly if the Sun goes into and out of clouds. Practice that – without introducing vibration from handling the camera.

Leave the rig for a couple of hours to test how the focus might shift, as it is certain to do, as the temperature changes through the morning or afternoon. Practice touching up the focus. People fuss over the “best” exposure, when it is poor focus that is the common spoiler of eclipse photos.

You can find more tips for practicing for eclipse close-ups at a blog I wrote for AstronomyByNight.ca.

WIDE-FIELD OPTIONS

May 10, 1994 annular eclipse in a series of multiple exposures every 10 minutes.

An alternative way to shoot the eclipse is with a wide-angle lens, but also equipped with a solar filter, as shown above. Frame the scene to include the expected path of the Sun, determined by using planetarium software such as SkySafari or Stellarium (my ebook also has charts). Take images every minute or so, then layer those onto an unfiltered image of the sky and foreground taken either before the Sun enters the frame or after it leaves it.

Practice that method now, to shoot images for a test composition as I show above. It layers filtered images taken at 5-minute intervals onto an unfiltered background sky image taken after the Sun left the frame.

However, composite images can be complex to plan and execute.

The partial solar eclipse of October 23, 2014 as seen from Jasper, Alberta, at a public event in Centennial Park as part of the annual Dark Sky Festival. This is a single-exposure image showing the scene near mid-eclipse with telescopes from volunteers from the Royal Astronomical Society of Canada, and the mostly clear skies above with the crescent Sun visible through the handheld polymer solar filter.

A simpler method for grabbing a souvenir eclipse photo is to simply hold a handheld solar filter in front of the lens to dim the Sun but leave the rest of the scene visible.

Again, you can practice that now to see what exposure might be best. For this type of shot I find black polymer filters best as they are less reflective than the Mylar type.

That method, or using a long lens or telescope will work well on eclipse day no matter where you are, either in the path or elsewhere enjoying the partial eclipse, as in the example image below, also from October 23, 2014, shot with my small scope at lower left in the image above.

The partial eclipse of the Sun, October 23, 2014, as seen from Jasper, Alberta, shot under clear skies through a Mylar filter, on the front of a 66mm f/6 apo refractor.

No matter the method and gear you use, success on eclipse day will require practicing beforehand to learn what can go wrong, and what works best for the setup you plan to use. Never assume something will work!

Clear skies on October 14! The annular eclipse that day will serve as a great dress rehearsal for the big eclipse to come – the total eclipse of the Sun on April 8, 2024. That’s the event you really want to get right!

– Alan, September 5, 2023

June 11, 2023

How To Photograph the Solar Eclipses

My latest ebook describes in detail the many techniques we can use to capture great still images and movies of the 2023 and 2024 eclipses of the Sun.

In the next few months we have two major eclipses of the Sun visible from North America.

On October 14, 2023 the Moon will cross the disk of the Sun creating a partial eclipse. But from along a narrow path in the western U.S. the Moon’s disk will be centered on the Sun’s disk but not be large enough to completely cover it. For a few minutes, viewers will see an “annular” eclipse, as above, as what remains of the Sun forms a brilliant ring of light around the dark disk of the Moon.

Six lunar months later, the Moon again crosses the Sun but is now large enough to completely cover the Sun’s bright disk. The result is the most spectacular celestial sight, a total eclipse of the Sun, on April 8, 2024. The last such total solar eclipse (TSE) in North America was on August 21, 2017, shown above. After 2024, the next TSE in southern North America will not be until August 23, 2044. (There’s a TSE in northern Alaska on March 30, 2033.)

In 2017 I prepared an ebook about how to shoot that year’s total eclipse. This year I revised and expanded the book extensively to cover both the 2023 annular and 2024 total eclipses. The new 350-page ebook explains how to frame the eclipses depending on where you are along the paths. New information covers the advances in camera gear, with more details added on shooting video. Revised tutorials cover new software and processing techniques.

Above is the ebook’s Contents page, so you can see what topics it covers, over an extensive 350 pages. I provide not only advice on lots of techniques and gear, but also suggestions for what not to do, and what can go wrong!

The Fundamentals

I discuss the filters needed, comparing the various types available, and when to use them, and when to remove them. (A filter is always needed for the annular eclipse, but failing to remove the filter is a common failing at a total eclipse!)

For the 2023 annular eclipse I explain how to shoot close-ups, but also another type of image, the multiple exposure composite. Framing, timing and exposing correctly are crucial.

I do the same for the 2024 total eclipse, as a wide-angle shot of the eclipsed Sun over a landscape is one of the easiest ways to capture the event. It’s possible to set up a camera to take the images automatically, leaving you free to enjoy the view of the event without fussing with gear. I explain how best to do that.

For both eclipses, many people will want to shoot close-ups with telephoto lenses or telescopes. It takes more work and more can go wrong, but I show what’s required for equipment and exposures, and explain how to avoid the common flaws of fuzzy focus and trailed images.

But good exposure is also essential. However, for a total eclipse close-up, no one exposure is best. It takes a range of exposures to record the wide dynamic range of phenomena during totality. That demands work at the camera.

Setting Cameras

I show how we can use a camera’s auto-bracketing function to help automate the process of taking a set of exposures, from short exposures for the prominences, to long for the faint outer corona.

Another option is using a continuous burst mode to capture the fleeting moments of the diamond rings at the start and end of totality in 2024. But this can also be useful for capturing the “reverse Baily’s beads” that appear briefly as the Moon reaches the inner contact points at the start and end of the annular phase of the 2023 eclipse.

Using a tracking mount can help with shooting a set of images during totality. I describe the options for choosing the right mount and telescope, and how to set it up for accurate tracking. I discuss the advantages — and pitfalls — of using a tracking mount.

Shooting Video

Video is now an important feature of many cameras. But the choices of formats and settings can be daunting! 4K, 8K, 4K HQ — what to use? I illustrate the differences, using the best practice target, the crescent Moon.

Choosing the right contrast curve for your video — such as CLog3 here — can also make a big difference to the final video quality. It’s important to get that right. You have only one chance!

I also devote a chapter to shooting time-lapses, with wide-angle lenses and telescopes.

Image Processing

Chapter 11 is the biggest, with 68 pages of tutorials on how to process eclipse images, using the latest software. I show the benefit new AI tools can provide, but also the oddities they can impart to eclipse images.

I illustrate how to use HDR software (comparing sample results from several popular programs) to blend multiple exposures for greater dynamic range.

I illustrate other methods of stacking and blending exposure sets, such as luminosity masks and stack modes. Examples are all with Adobe products, but the methods are applicable to other layer-based programs such as Affinity Photo.

The processing chapter ends with illustrations on how to create layered composites from images taken at multiple stages of an eclipse.

What Can Go Wrong?

The ebook ends with advice for the ambitious (!) on how best to use several cameras to capture different aspects of the eclipse. And I includes lots of tips and checklists to ensure all goes well on eclipse day — or what to do for Plan B if all does not go well!

The ebook is available for Apple Books (for Macs and iPads) and as a PDF for all devices. Links to buy and more details on ebook content are at my website at www.amazingsky.com/EclipseBook.

I’ll be posting more eclipse “tips and techniques” blogs in the coming months, so be sure to subscribe.

Thanks and clear skies!

— Alan, June 2023