Tradition. You print ‘hello world’ first if you’re starting to learn code, you take photos of the moon if you’re starting to learn astrophotography with just a smartphone because you’re graduated and unemployed and bored and too broke to actually buy a camera but still want to keep your interest in astronomy alive.
“There is more computing power in a handheld calculator than the computer on Apollo 11 that put man on the moon”, say thousands of articles on the internet. While being partially true, in terms of memory, size and processing power any modern ‘digital’ instrument is miles ahead of the vaccum tube computers of the Apollo era, comparing the Apollo Guidance Computer (AGC) and calculators is a bit unfair. The AGC is a purpose driven, focussed machine that was the pinnacle of technology at its time while a calculator is a general purpose machine. It’s true that my laptop is so much advanced than my smartphone but my smartphone is still better at making phone calls because it is its purpose. Nonetheless, it did get me thinking and by ‘thinking’, I mean googling keywords and checking out what other people have said on the internet. Nobody thinks for themselves anymore. That’s so last year.
Turns out it is totally possible to put things and/or control things in outer space using even the first iPhone or old Android phones. There have been many pet projects undertaken wherein people have used self-designed smartphone apps to do just that.
However, it didn’t quite look like something I could take up as a hobby. These were small yet serious feats of engineering. So I turned my attention to photography. There is an abundance of information online regarding astrophotography using smartphones. What fun would it be if I just read and repeated? So I put down my own constraints – One. Use only equipment I already own. Two. No spending money at all. Three. Learn everything on my own just from online tutorials. No help from friends who call themselves photographers. I used to dream of being an astronaut, or maybe an astronomer. I did not even know what work that would entail but I always pictured myself in a lab coat in an empty, dark observatory on the top of a hill somewhere off country. It is quite evident that none of that can happen now but I can switch out the observatory to my binoculars and the lonely hilltop to my own corner on my rooftop. Same thing. Almost.
I did something similar about 6 years ago, where I wanted to teach myself stargazing and did take quite a few strides in that direction but couldn’t keep up in college though. I did learn a lot and they would serve as a prerequisite for this attempt.
The ‘equipment’ I own is a Celestron Skymaster 16 x 70 binoculars, with the cheapest tripod I could buy online and some star maps and guides. The smartphones available are a Lenovo P2 (13 MP, f/2.0, 2160p at 30fps), Moto G4 (16MP, f/2.0, 1080p at 30fps) and Redmi 4A (13 MP, f/2.2, 1080p at 30fps). I use Camera FV-5 to shoot and Adobe Lightroom and Snapseed to post process the images and Registax for stacking images.
Step one was learning what those numbers meant. The megapixel count such as 16MP and 13MP, while being great to capture details in bright light, do not matter as much for low light photography. It is the size of the pixel that matters most, larger being better. Since I have no control over that, I am going to completely ignore that. Next is the aperture and again, bigger the better as it is a measure of how wide the lens is and we need to allow in maximum light. It is to be noted that f/2.0 is a wider aperture than f/2.2. Math is math. Finally the exposure or shutter speed. By default, smartphones have very fast shutter speeds. However astrophotography requires much prolonged ones. It is however a matter of balance. Since the Earth doesn’t care if you’re trying to take photos of its neighbours or not, it’s going to keep spinning around and having very high exposure times could lead to star trails. Even though most phones these days come with a ‘pro mode’ in their camera apps allowing us to manually adjust ISO and focal lengths, most still contrain the exposure time. To break out of these, I use the Camera FV-5 app which many recommended online and is very easy to use for a beginner.
After reading up quite a few articles on cameras and astrophotography, I headed to my terrace to set it all up. I could either take photos directly using my phone or I can simply put it next to the binocular’s eyepiece and take an image. This is called afocal photography and that is where we shall begin. Because there’s too much light pollution where I live in and the sky was rather cloudy last night. There were very few stars visible to the naked eye as such and shooting directly from my phone would only yield blank, black photos. Bad for the self-esteem.
There were issues. My very responsible younger self had felt bad about spending a large amount on the binoculars and had bought the cheapest tripod available. Which turned out to be a huge pain in the ass for turning and adjusting the position. I would set the binoculars in place and begin tightening the knobs to hold it in place and the setup would also turn, in the direction I’m screwing it in. Also one of the objective lenses in the binoculars had slightly moved inwards while I was moving it from college to home, and I have no clue where to take it to get it fixed, so that lens remains perpetually closed now. So I’m essentially losing half my light gathering power. Don’t you just love it when things fall into place? And last but definitely not the least, holding a smartphone weighing 177g perfectly still to take one picture is the best arm workout there is. By the time I get really good at this, my biceps are going to be huge. Translation : after 3 seconds, your arms start aching like a bitch. Anyway since I had decided just to do the moon for the night, my work was pretty easy, the moon doesn’t require any extended exposure time at all. So here are the results,
Not bad for day one, eh?
Lessons to be taken away : This is fun. Work, but fun. There’s a lot to learn. I’ve been reading up on stacking where I could take a series of images or a video and split it into frames subsequently, and then stack them digitally to get a much more detailed image. Got to try that. I already got Registax and have been playing around with it a little. Rule two is going to screw me a lot. A simple smartphone mount for the tripod would do me wonders and is cheap as well. But I can’t already break a rule. So need to improvise. Would probably break and order one by day four. Exciting nights lie ahead.