In 2017, I was already a member of a local astronomy group and running a scicomm project. On August 21st of that year, I had the opportunity to watch a partial solar eclipse. It was a truly remarkable experience and it is when my journey started. Six years later, on October 14th, 2023 I would have an opportunity again to observe a solar eclipse in my home state in Brazil. This was an event that many amateur astronomers had been waiting for and it was a hot topic in the 2018 edition of an Astronomy Symposium in Araranguá, Brazil. I had five years then to prepare for the big day.

In the following years, I learned more about photography and I planned to be able to capture the eclipse. Ideally, capture photos from the partial phases and then record in video the annularity. Skip a few years and in the first semester of 2022, I moved to the United Kingdom. This added more complexity to the entire plan, yet I was determined to observe the eclipse.

Planning phase: April to September 2023

I already knew plenty of details about the eclipse. The type, duration, and path were already known for years. The good thing was: that the eclipse path was directly over the southern region of my home state in Brazil. A region where I had lived for a few years and had a lot of relatives nearby. This made things easier because they agreed to host me and several other colleagues from Sama (Maranhão Astronomy Society).

In April I bought a used camera – a Canon EOS M5. Not the best around, but it was good enough for the job. It helped the fact that I also love photography in my free time. The next step was to buy a telephoto lens, so I could point it to the sun during the eclipse and take my shots. After some research, I discovered that the recommended focal length to capture an eclipse is between 400mm and 500mm. Some cheap kit lenses were available, including the one that I decided to go with: Canon EF 75-300mm f/4-5.6 III. Because my camera sensor format was APS-C, a cropped sensor, the lens gives me a 35mm equivalent between 120mm and 480mm. Well in the range that I needed.

The last essential items were a solar filter for the lens and a camera tripod. With these, I could safely photograph the eclipse. For the filter, although there are some out-of-the-shelf options, I decided to make one on my own. I used a step-up ring (58mm-62mm), a 62mm UV filter, and a solar filter sheet. With these, I covered an area bigger than my lens diameter for extra safety. With this, I started testing my equipment for the eclipse by taking shots of the Sun.

Because we were also headed to an area where the local population was likely to observe the eclipse as well, I also bought about 150 solar eclipse glasses. Plenty for myself, my relatives, my astronomy club colleagues, and the local population as well (and also some as an emergency backup).

Choosing the location to observe

As my fellow amateur astronomer Carlos Portela once said, the best place to observe the Eclipse is where you can observe it. All considered, I chose three candidate locations in the southern region of Maranhão, Brazil. They were:

• Entroncamento entre a BR-230 e a MA-006, Balsas, Maranhão, Brazil
• Povoado Brás, BR-230, São Raimundo das Mangabeiras, Maranhão, Brazil,
• Povoado Vale Verde, BR-230, São Raimundo das Mangabeiras, Maranhão, Brazil

All of these locations were within the annularity path. I knew these locations myself. Also, it helped the fact that usually around that time of the year, the weather was not so cloudy. The last two points also had easy access to electrical energy. All of them have a clear view of the sun around the time of the eclipse on October 14th. In the end, I ended up deciding to observe from the second location as it was also far away from cities nearby and allowed an astrophotography session on the nights before the eclipse.

After deciding on the location, there was the issue of the staying. Fortunately, some relatives offered their house to receive me and twelve more colleagues of Sama. Given that we were a quite big group, we also decided to hire someone to take care of the meals for the whole team, so it was one less thing to worry about.

Buying a telescope

So far I had my items ready and tested months before the eclipse. During this same period, I bought a small Maksutov-Cassgrain telescope to combine with my camera on some occasions. I also planned to use the telescope to project the eclipse to a white surface, so people could observe it safely from there and for observation of the planets on the nights before (and after) the eclipse.

I ended up choosing the Sky-Watcher Skymax 90 OTA due to its compact size and amazing optics. Also important, I bought a proper solar filter for the telescope for safe observation of the Sun. I also bought a T-ring adapter for the Canon EF-M mount and an Altazimutal mount later for it.

Of course, I’ve tried to take some photos of the moon at night with this telescope. The focus was not very sharp when combining the telescope and camera, but I still got some usable images.

Traveling

I bought my tickets back in June. My travel itinerary from London included a 2-hour flight to Lisbon where I spent one night. Then an 11-hour flight from Lisbon to São Paulo. From there, wait around six hours before getting a flight to São Luís where I arrived on October 2nd. After spending some days there, I took a coach to Balsas, located around 800km from São Luís. A 12-hour long trip. I followed the same itinerary in reverse on my way back to the UK.

I decided to arrive in the region that I chose to observe a few days before for two main reasons:

• Buy necessary items in advance (water bottles, snacks, white paper sheets) and leave them at the selected location.
• To have plenty of time to test all the equipment at the location that we choose. This was done to avoid any last-time issues on Oct 14th.

October 11th and October 12th: Astrophotography

Because the region had low light pollution, it was an amazing site for astrophotographers. Tavares Junior, me, and some colleagues took great photos of the sky the night before the eclipse. Since everyone from our astronomy group lives in the capital and biggest city of the State, São Luís, where there is a high level of light pollution, this was a great bonus to the trip.

October 13th: Rehearsal

On the day before the eclipse, we made a full-time rehearsal in preparation for the eclipse. This was very important because allowed us to discover some issues with the point from where we would observe the eclipse. Some of them were:

• Power outlets: we choose to observe the eclipse under a tree near one of our host houses. It was near enough to allow us to have a power supply through some extension leads. This was easily sorted.
• Obstructed view of the sun: although the sky was quite clear on the days before the eclipse, we had one obstacle: a tree that would obstruct our view of the Sun during the eclipse. The landowner allowed us to cut it down on the following morning.
• Temperature: The temperatures in the region can get as high as 33 °C in October. Usually even higher. The rehearsal allowed us to check for any equipment issues caused by the high temperature. Although I was expecting to have some issues with the camera, we had none. Regardless, we also used some handmade cardboard protection for the telescope tubes and camera bodies.

We had some cloud obstruction during the test observation, but nothing that compromised our observation of the Sun. We would be able to observe the eclipse even with some clouds in the sky.

October 14th, 2023: The big day!

Although we had some clouds in the sky that morning, the weather forecast was good and favorable for our observation. We expected some clouds all day. Our equipment was ready and we had a clear view of the sky.

The eclipse started well for us. We had a clear view of the Sun in the sky and were able to capture the start of the event. Some locals mentioned a change in animal behavior (birds, chickens, goats) during the eclipse. After the initial 40 minutes, we noticed a small temperature drop in the area we were in.

The partial phase started at 15:16:37. The annularity was expected to start at 16:38:59 and finish at 16:43:19. The maximum would be at 16:41:08. The eclipse would have its end at 17:53:07, a few minutes before the sunset. We didn’t expect to get all of the final partial phase.

Unfortunately, the weather changed very quickly before the main event: annularity. Clouds started to obstruct our view of the eclipse around 30 minutes before the annularity and we could not take more photos after 16:12. A few minutes later we had heavy rain and missed the rest of the eclipse.

The learning

Although I couldn’t achieve my main goal: to photograph the annularity during the eclipse, the whole experience was amazing. Apart from the weather, which we didn’t have any control over, everything that was planned was executed very well. Equipment, location selection, group travel logistics, meal preparation, and the astrophotography sessions all happened as initially planned. Practicing and testing everything in advance was a really important factor in all this. This experience will be useful when planning to observe upcoming eclipses and other astronomical events.

The most important thing that I took from the eclipse was that I managed to observe the eclipse with my family, fiancee, best friend, and estimated colleagues from my astronomy group. The same goes for many of the locals who hosted us during those days. We also did some scientific communication work with the community that hosted us and provided a safe way for them to observe a once-in-a-lifetime astronomical event.

Recommended readings

• Recommended Lenses for Shooting a Solar Eclipse on Any Budget, Todd Vorenkamp. B&H Photo (May 2023)
• What causes an annular solar eclipse, Jamie Carter. BBC Sky at Night Magazine (Nov 2023)