Astrophotography from the Heart of Los Angeles: Behind the Lens (and Telescope) with Stephen Li

For this edition of our Behind the Print blog series, we’re honored to feature the extraordinary work of astrophotographer Stephen Li. A first-generation immigrant from Guangzhou, China, Stephen has turned his lifelong curiosity for science and art into a breathtaking exploration of the cosmos.

Working under light-polluted skies to achieve stunning astrophotography from the heart of Los Angeles, he captures deep-space wonders with budget gear and boundless dedication. Proving that passion, perseverance, and faith can turn even the most challenging conditions into inspiration. His images don’t just reveal distant galaxies and nebulae; they tell a story of resilience, wonder, and the beauty of creation itself.

Instagram: https://www.instagram.com/astro626photos/ 

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Q&A with Stephen Li:

How did your journey with photography begin, and what convinced you to take the leap into turning it into your profession?

It is a long story; I would characterize it as drawn-out baby steps. It began about 23 years ago when I got my first camera phone, the Samsung SCH–X590, the iconic first flip phone with a rotatable camera, making selfies possible, and since then, I’ve been casually taking photos with different phones through the years. I got a bit more serious in the hobby when I got a Sony RX100 point-and-shoot back in 2014, shooting the October 8th Supermoon and full lunar eclipse. That experience got my childhood space appetite going.

In 2022, after learning to use the manual mode on my new Canon M6 Mark II, I captured the Super Blood Moon, and that was the catalyst that got me into astrophotography. With the COVID lockdowns in full swing, I dove headlong into AP. Being a natural night owl, I had baby duties with Irish twins; the second one was born later that year. With my wife working full-time, I was the primary care provider for the boys. I was able to focus on my hobby that turned into a passion project, learning all I could to improve my craft, and once I believed I was “good enough”, I decided to venture out to the marketplace and became a local street fair art vendor to share my love for astrophotography and to show others that by overcoming obstacles one’s childhood dreams can come true.

Do you think of your astrophotography as more “science” or more “art,” or a balance of both?

I would have to step back a bit for a fuller answer. I believe the Creator God spoke the Universe into existence and created the Cosmos for beauty and admiration. I tend to think it was the first act of art.

As man discovered the stars, he began to use instruments to explore and try to understand them using standardized, scientific means to measure and interpret what is observable.

The early fathers of science and astronomy, Isaac Newton, Galileo Galilei, and Johannes Kepler, sought to discover for themselves the beauty and creative order of the heavens. They laid the foundation for science as we know it, bringing about the rapid pace of research and exploration by NASA and other space organizations.

There is a fine balance ever since.

Even the scientific community has inadvertently turned it into somewhat of an art form due to having to show contrast between the Hydrogen-alpha and Sulfur II wavelengths because they are naturally red. Sulfur II is a deeper red, and it gets washed out to the predominantly more abundant Hydrogen signals. To differentiate them, they use the Hubble color palette; SHO. By assigning the red, green, and blue (RGB) to Sulfur II, Hydrogen-alpha, and Oxygen III, it gives a nice contrast and is visually appealing.

Case in point, as seen in the iconic Pillars of Creation within M16, the Eagle Nebula. Amateur Astrophotography as a hobby is mainly artistic because everyone processes their photos using different tools, some free, some paid, and a combination of both, with varying skill levels, just like terrestrial photography.

It is an art form as people tend to enhance certain features, colors, or a certain crop to make it their own.

What influences your choice of subject in the night sky, whether it’s scientific interest, visual appeal, or personal meaning?

It depends on how I feel as well as the season. Nebulae are mostly visible in the fall and winter, and from late winter to summer, it’s considered galaxy season. Nebulae season is my favorite because there is a treasure trove of gorgeous targets for visual appeal.

When I first imaged the Pillars of Creation in July, it was both for scientific interest and a personal milestone because, scientifically, that is the most iconic Hubble target, while also personal because a beginner astrophotographer with budget gear can capture and process it with some skill to make a decent comparison to the icon without spending billions.

To achieve that was a big step in personal achievement.

Long exposures can introduce a lot of noise into astrophotography. What techniques do you use to reduce it (ie. calibration frames, stacking software, etc.), and which methods have worked best for you?

So, there are 12 types of noise associated with astrophotography.

The main ones that make the most impact for me in LA are skyglow noise from the heavy light pollution. LA is the largest metropolis with the highest concentration of light pollution in the nation. To mitigate this, I would have to use aggressive light pollution filters and narrowband filters, depending on the target, and aim for targets closer to zenith rather than the horizon to minimize the depth of atmosphere.

There’s walking noise which is a large diagonal streak pattern across each image, caused by slight image drift, which is a sign of poor polar alignment, mostly without using a guide scope and guide camera to compensate. You would typically have to visually align the telescope’s equatorial mount to Polaris, the north star but since my neighbor’s two-story house is in the way in my backyard, I use software to plate solve 3 sections of the sky to determine how much drift it has. It would take 3 images, and it will measure the stars’ distances and gives me suggested adjustments in the declination and azimuth axes to align the scope to the celestial pole. This is a more advanced way to make sure I’m aligned with the rotation of the Earth to reduce this noise, and that the mount would have to work less to make any corrections.

Low signal-to-noise ratio (SNR) is due to not taking enough photos to the amount of light pollution. The more photos, the better, but there is a diminishing return. To double the SNR, you have to quadruple the number of sub exposures. I typically average 5 hours of total integration time for most of my final images. That is usually the minimum for bright targets. For dimmer targets, I’ve done 13 hours for the Jellyfish Nebula. It is quite dim and low on the horizon, so I spent a month just capturing photons before processing it.

Then there’s thermal noise and hot and cold pixel noise. Thermal noise comes from long exposures and the hot and cold pixel noise comes from defective pixels on the camera sensor. Cold ones are dead and are dark spots, while hot ones are very bright, caused by dark current. To reduce these three types of noise, I have upgraded from using a Canon mirrorless camera to a dedicated cooled astronomy camera. The thermoelectric cooling on the astro camera greatly reduces this noise, typically starting at -15°C.

What’s the biggest challenge you face due to light pollution, weather, or atmospheric conditions, and how do you overcome it?

That would have to be light pollution for deep sky objects.

I chose to shoot in my backyard, in the worst sky conditions for the challenge. For targets like galaxies, reflection nebulae, and star clusters, I use the best of the best broadband filters available made by IDAS in Japan. They are superior to the Germans and especially the Chinese in terms of quality control, batch consistency, and they perform to spec. These groups of targets emit a wide spectrum of visible light, so a filter that allows most of the light to come through while reducing the light from skyglow, sodium, and mercury vapor and LED lights helps improve contrast.

For nebulae, which are objects made of mostly gases and dust, I use ultra-narrowband filters that allow only Hydrogen-alpha, Oxygen III, and Sulfur II wavelengths to come through. These are much narrower at 7nm and 3nm wavelengths. It isolates the nebula and makes it pop compared to the dark space background.

Nebulae glow with interesting shapes due to the intense stellar radiation from nearby stars, ionizing the gases, causing them to glow a particular color. The stellar winds and eruptions throw the gases and dust to form interesting structures as we see them.

I usually use the analogy of driving with headlights on through a foggy, dusty country backroad when asked by the public what a nebula is for illustration.

What advice would you give to new and aspiring artists?

For budding astrophotographers, learn the basics, and get a larger mount than what you think you will need because you will grow out of it. Learn to process the data you have.

Buying expensive gear is not the answer. I started with budget gear 3 years ago and still use them.

Maximize your skill with the equipment and the processing software before you spend more money on shiny, new, fancy equipment. There are so many established astrophotographers out there on YouTube and Facebook groups who are willing to help. Also, get a mentor if you can find one. I have a couple of mentors who have graciously given their time and experience to help me in the beginning.

The biggest advice is that if you ever want to sell your photos, once you get decent at it, don’t listen to those who say you can’t make any money selling your images. I’ve sold mine as art from my own handmade products created in my garage workshop to having fine art-grade media printed for me by Artbeat Studios every Friday night at a local street fair for two years as of October of this year.

I’ve made some huge sales the last couple of months that broke several personal records in the 4 digits on a single night. Don’t listen to the naysayers, but keep on shooting and growing in your craft.

For artists in general, keep creating your art. Don’t create it to please others, create it for you and show others why you do what you do.

I find that the story behind the art is what drives their desire. Making that personal connection and sharing it with passion is what brings collectors to you. From my experience, people at the street fair are always amazed that I can capture these glorious cosmic objects from my LA backyard and ask if I work for NASA.

I do not, though I’m flattered to hear it.

I would tell them my techniques and the stories behind each piece, the challenges of how I overcame them, that make my art more meaningful to them. So, be real, be genuine, and let your passion flow through as you showcase your art.

As someone who works with stellar nightscapes, what printing products or finishes help bring your vision to life, and why?

I find that ChromaLuxe HD Metal is the best for my art.

Many have asked if my pieces are glowing due to the Epson archival dyes’ fusion into the bright aluminum. With a glossy finish, it really sets it apart as fine art compared to other media types. The metallic finish is my favorite because it gives a holographic metallic iridescent sheen to the prints, the stars and the nebulae pop off the print with track lighting or recessed lighting, and it is like no other finish.

My dream finish would have to be the metallic HD Metal with a matte finish. The matte finish would represent the depth of the blackness of space, and the metallic shine would make the brighter objects glow for a very dramatic, high-end effect.

When that is not available, the next best thing would be the anti-glare acrylic print with metallic paper.

What led you to partner with Artbeat Studios for your fine art printing needs?

Early on, when I first decided to sell my astrophotos 2 years ago, I did some research and came across Artbeat Studios. Earning the award of best metal print company by photographytalk.com 2020-2023 caught my eye.

The website is very easy to use, and I love the visuals of how my photos would come to life as I build each order while seeing the previews in real time.

Being local to me, I can pick up my orders and not have to wait for shipping.

Once I got my first order, I was convinced of the quality. I had to learn fast and improve my astro processing skills within the last year to give justice to the materials and workmanship that is consistently maintained.

Charles has been taking care of my orders, answering all my questions, and giving me suggestions since day one in a professional, friendly manner that tops the whole experience.