Interview with Astrophotographer Juan-Carlos Muñoz

Astrophotography can sometimes be considered as a mean of popularizing astronomy.

Images illustrate some technical and scientific concepts which remain difficult to imagine.
Juan-Carlos Muñoz is an experienced astronomer who loves sharing his passion through capturing the sky of one of the darkest places on Earth.
AstroSpace had the opportunity to meet him during the 2019 total solar eclipse event from La Silla Observatory in Chile. In addition to his remarkable photography work, Juan-Carlos is a keen astronomy communicator. We invite you to discover himself through his own words: (Credit image: Juan-Carlos Munoz-Mateos)

★ Could you introduce yourself?

"My name is Juan Carlos Muñoz Mateos, and I’m currently a staff astronomer at the European Southern Observatory (ESO) in Chile. I’m originally from Spain. I did my undergrad in Physics at Complutense University in Madrid, and then got my PhD in Astrophysics in 2010 at the same university. Right after that I moved to the US and started working as a postdoctoral researcher at the National Radio Astronomy Observatory in Charlottesville, Virginia. In 2013 I got an ESO Fellowship and moved to Chile, and since 2015 I’m a staff astronomer. Here at ESO my time is split between my research on galaxy evolution and my functional duties at Paranal Observatory, where I support night observations with the UT2 and UT3 telescopes (two of the four 8 meter telescopes we have)."

Two auxiliary telescopes at Paranal facing the Milky Way with green/orange airglow. Credit: Juan-Carlos Munoz-Mateos

★ How did Astrophotography come to you?

"I was always interested in astronomy as a kid. I started to experiment with astrophotography as a teenager, with a very basic film reflex camera. I tried a bit of everything: wide-field shots of the Milky Way, planetary imaging… The pictures were far from being good, but I did learn a great deal. During my undergrad and PhD I was too busy and couldn’t devote much time to astrophotography. But then in 2013 I moved to Chile and was instantly mesmerized by the Southern night sky, and my interest in astrophotography was sparked again."

★ What does an ESO Photo Ambassador consist in?

"The ESO Photo Ambassadors are a network of astrophotographers who routinely take images of the night sky from any of the observatories managed by ESO: Paranal, La Silla, and ALMA. Some Photo Ambassadors like me work for ESO in some capacity, but others are not affiliated to ESO. The ESO outreach team then publicizes our images in their various social media platforms."

Moon Halo and sodium lasers taken at the Very Large Telescope. Credit: Juan-Carlos Munoz-Mateos

★ Through your images, we directly identify a passionate scientist who is keen to share his passion with the general public on social platforms. Each of your images is accompanied with an accurate description of the subject or a story. As a matter of fact, astrophotography is a mean of sharing your experience and your knowledge in astronomy. Is it important for you to be involved in outreach?

"Definitely! Outreach is an essential part of my job. After all, ESO’s observatories are built and operated with public funding, so I firmly believe in communicating to the public what we learn about the universe with these wonderful facilities here in Chile. In this sense, astrophotography is a very effective tool, as it’s the epitome of the famous saying that “an image is worth a thousand words.” Whenever I post one of my pictures, I always like to explain the science behind whatever is in there: the structure of the Milky Way, the physics of optical phenomena like solar halos or the green flash, or how we use lasers to correct the atmospheric turbulence and obtain tack sharp images of astronomical objects. People always appreciate these explanations and ask lots of follow up questions, which motivates me to push my astrophotography in new directions, showing different subjects every time."

★ What are the most exciting moments you have ever lived while capturing the sky? or what is your favorite subject to photograph under the Chilean sky?

"While I love photographing the Milky Way, my favorite subject is actually not a celestial one: it’s the lasers we use to correct the atmospheric turbulence. These lasers excite sodium atoms located in a layer about 80 - 90 km above the ground, creating artificial “stars” whose rapid twinkling we monitor using devices called wavefront sensors. A special computer analyzes this twinkling, and sends instructions to a deformable mirror, which changes its shape several hundred times per second, counteracting the atmospheric blurring.

The Unit Telescope n°4 is probing the upper atmosphere with its 4 laser guide stars. Credit: Juan-Carlos Munoz-Mateos

I’ve photographed the lasers over a variety of backgrounds: the Milky Way, the Magellanic Clouds. I absolutely love the futuristic feel they impart on my images, and they provide a good excuse to explain the science behind the high tech that we use to observe the night sky.

The 4 laser beams propagating through the atmosphere and pointing towards the Large Magellanic Cloud. Credit: Juan-Carlos Munoz-Mateos

As for the most exciting moment I’ve ever had when imaging the sky, it might sound paradoxical after what I just said about high tech, but it happened with the most basic, lowest tech camera I’ve ever used: a soda can with a pinhole and a sheet photographic film inside. This was part of a collaboration with Diego López Calvin (@solarigrafia), a Spanish photographer who specializes in long exposure pinhole photography. He sent me some of his custom made pinhole cameras, which I placed in several strategic spots at Paranal Observatory. Eight months later I collected the cameras and gave them back to Diego, who scanned the films and sent me the final pictures. Those images are completely surreal, as they show the ever-chaning path of the Sun on the sky over all those months.

An 8 month trip across the sky of Paranal. Source  

The excitement came from the fact that I had no idea how the images would turn out! In the era of digital photography we’re spoiled by instant feedback from our cameras: we shot at the sky, and within seconds we can review the images and correct the settings or the framing if necessary. But for this project I didn’t have that luxury: I had carefully planned the framing of each pinhole camera, but I couldn’t know for sure whether I got it right until several months later. That lack of immediate feedback resulted in a very fulfilling experience."

★ What gear do you use?

"My camera body is a Canon 6D, which behaves quite amazingly under low light conditions. For wide field shots I use the Rokinon/Samyang 14 mm f/2.8 and 24 mm f/1.4 lenses, which are very luminous and much more affordable than other similar lenses. When I need a tighter framing I use a Tamron 45 mm f/1.8, which again is really luminous and has a superb image quality. When shooting the Sun and the Moon I use a Tamron 100-400 mm zoom lens. Finally, my main workhorse lens (not for astrophotography) is a Canon 24-105 mm. I also own a Tamron 90 mm f/2.8 macro lens; while I use it mostly for macro photography, it performs rather well as an astrophotography lens. My tripod is a Sirui T-025x, very light, compact, and sturdy."

Rare Triple Green Flash taken from Paranal Observatory. This image was shortlisted for the Insight Investment Astrophotographer of the Year 2019. Credit: Juan-Carlos Munoz-Mateos

★ Some of your images were published in professional magazines or websites.You made the APOD at least once, you were shortlisted by the 2019 Insight Investment Astronomy Photographer of the year… but for you, which image are you the most proud of? Your personal favorite?

Cosmic Marble. Source : APOD.

"It might not be a very original answer, but my Cosmic Marble image (the one that made it into APOD) is by far my favorite. The reason is that in astrophotography (or landscape photography in general) it can be really hard to evoke emotions or tell a story, which is what photography is all about. But that image somehow resonated very well with a large audience, and different people interpreted that image in different ways. To some, it reminded them of Orion’s belt from ‘Men in Black’; others saw Sauron’s Palantir from ‘Lord of the Rings’, or an Infinity Stone. One twitter user compared it with the Aleph in Borges’ short story - a point in space that contains all other points and that allows you to contemplate the universe from every angle at once. My original intention with that image was much simpler: I just wanted to create the illusion of imprisoning something as big as a galaxy into a small crystal ball. So seeing so many people interpret that image in so many original ways that I could have never anticipated was very rewarding."

★ Where can we find back Juan-Carlos Munoz on the Internet?

Instagram & Twitter: @astro_jcm

Facebook: www.facebook.com/JCMunoz.Photography

Flickr: https://www.flickr.com/photos/astro_jcm/

Personal webpage: http://www.sc.eso.org/~jmunoz/ (this mostly focuses on his research and Paranal activities)

This interview was carried out by Guillaume Doyen (AstroSpace) and is the result of a communication project proposed during the #MeetESO program.