What kinds of telescopes do you have?
My main imaging telescope is a 12″ f/4 Newtonian. It’s about 40 inches long and weighs about 70 pounds when kitted out. It lives inside a dome observatory year round, making it really easy to get going at any time. It rides on a heavy duty equatorial mount, and uses an APS-C size color camera. This telescope, completely set up, weighs about 270 pounds in total. You can see why it now lives in a dome.
My smaller, wide-field telescope is a 72mm doublet refractor. It lives on a small equatorial mount, and I am able to carry it fully set up out into the backyard, making setup easy. It uses a micro 4/3 size color sensor.
More details and images can be found on my equipment page.
I also have a 12″ f/5 Newtonian on a Dobsonian mount that I started off with visually. I put a DSLR camera on this telescope, and that’s how I got into astrophotography.
Do you just hold your cell phone up to the eyepiece?
I get asked this question quite a lot, and, unfortunately, no, you cannot just hold your cell phone up to an eyepiece and get pictures like I do. It’s possible to get an image of something like the Moon or planets, but not with the extremely dim deep sky objects that I typically image.
I use a camera that is based around an ASP-C sized backlit Sony sensor. This camera has active TEC cooling that allows it to not only have reduced noise in general, but to have consistent noise. This allows the noise to be significantly reduced by calibration images in preprocessing.
How did you get into astronomy?
I have been interested in astronomy and outer space ever since I was a child. In middle school I fell in love with the Hubble Space Telescope and its images, even going as far as to make a model of the HST out of coffee cans and aluminum foil for a fifth grade science fair. I received a small department store refractor sometime in my childhood, but I do not remember using it that much. I spent a lot more time reading magazines and books at the local library.
After I graduated high school, I tried taking my cheap refractor telescope to an astronomy night at a local park. The very nice gentlemen there showed me the basics of the scope and how to use the equatorial mount. While my telescope was not good for much, I was allowed to use Rich Ruggles’ big Dobsonian, and I fondly recall seeing the Pleiades for the first time in a telescope and seeing the faintest blues of the cluster. That moment always stuck in my mind.
Around 2018, I finally had the notion to purchase my own telescope. Like the one I remember using, I went for the biggest Dobsonian I could afford at the time. I ended up with a SkyWatcher 12″ f/5. I took it out a few times to look at the moon, planets, M42, the usual beginner targets. Well, I tried my best, but I just wasn’t blown away by what I saw in the eyepiece, compared to all the beautiful images I have seen published prior. So, I bought a well-recommended DSLR, the Nikon D5300, and stuck it in the focuser. What a mistake that was! I fell down the rabbit hole of everything astrophotography.
I tried to use the Dobsonian to the best of my abilities, building a plywood equatorial platform for it so that it would track the sky, and eventually I ordered a professionally made equatorial platform. I had an absolute blast with this simple setup and spent many wonderful, long hours under the sky, in the freezing cold or fighting the mosquitoes, trying to manually find targets in that scope. When you take your first image of where you think M51 should be, and 10 seconds later you see those beautiful spiral arms for the first time yourself, you’re hooked.
After seeing a plethora of the most common and some uncommon targets, I began to want more from my imaging. I loved the field of view and depth of a large Newtonian, so I went with a similar, faster telescope, a robotic mount, and an autofocuser. This allowed me to enjoy the beauty of space myself, in a more controlled way, and in the comfort of my air-conditioned home! My integrations went from 50 minutes to 8 hours to multiple nights, and I keep striving to get better pictures each time. The best part about this hobby is how much there is to learn, to do, to experiment with, to discover, and to invent. Every time that my computer finishes integrating all my data on a target, and I do that initial stretch to see what I got, I get chills.
If you had told me when I was a kid that I would be able to discover the universe myself, with such depth and detail, from the comfort of my backyard, I would have never believed you. I thought only Hubble could do that!
Have you discovered anything yet?
Not yet. I’d like to get more into astrometry and perhaps find some dim asteroid lurking out there, just looking for a name.
Amateurs do discover a lot, however. I frequently see reports of amateurs discovering supernovae, planetary nebulae, asteroids, and comets. Amateurs can also contribute a lot of citizen science in the methods of spectroscopy and photometry, dealing with different types of stars and exoplanets. These are both topics that I am interested in getting more familiar with.
What’s the farthest thing you have seen?
The most distant object that I am aware of observing so far is quasar SDSS J160622.30+174805.5. This object has a redshift z = 3.87901 +/- 0.00031 and a z-band magnitude of 18.323 +/- 0.034. Assuming a flat universe, this means that this quasar had a light travel time of 12.104 billion years and a comoving radial distance of 23.585 billion light years, or how far the galaxy would be from us now. The heliocentric velocity, the speed at which the quasar was receding away from us when the light that hit my telescope left it, was 1,162,899 km/s, or about 3.87 times the speed of light.
How do we know how far away all this stuff is?
With spectroscopy! Just like the sound of an ambulance as it approaches you and then recedes, light also follows the Doppler effect. For example, using a device on my telescope, I was able to take the spectrum of a distant quasar and measure its redshift myself. This allowed me to deduce its light travel time of 8.961 billion years!
What do you mean when you say a picture is x hours?
This means that I have taken a number of exposures of a target such that all the exposures add up to the specified exposure time. The objects I tend to image are so faint, so far away, that a single exposure, even a several minute exposure, barely captures all but the brightest details. So you take the same exposure over and over on the target. I will typically do this for four to seven nights on a target now, as I like to get around 500-600 images on a single target. Each image I take is four minutes long.
And what do you do with all of these exposures?
Basically, you take the average of all of them. When you are sampling something, the true value is in there along with some noise. In astrophotography, there is a lot of noise. If you take the average of a large sample of noisy things, you tend to approach the actual value you want as the number of samples goes up. Simply, to get a picture that looks twice as good, you need four times the exposure.
The quality of the image depends mostly on light pollution. My backyard does not have a great sky, so to make a nice image, I might need 30-40 hours on something. If I lived in the Atacama desert, I might need only 4 hours to make the same quality image.
Do you ever get any sleep?
Yes, quite a lot, in fact!
Both of my telescopes are on fully robotic mounts, contain autofocus motors, and are controlled by computers. With the success of plate solving, using a database of the known positions of stars to determine in what part of the sky an image is, I can program the telescopes to image what I want in a fully automated fashion. The telescopes will wait for dark, slew to targets, plate solve, autofocus, do meridian flips, and go to sleep at the end of the night, all on their own. The telescopes will also happily image multiple targets for me each night, and I can program them to know where the horizon is, so they will switch targets or go to sleep when a target goes behind trees.
What is your favorite thing to image?
My favorite subject to image is very distant clusters of galaxies, such as the Hercules Galaxy Cluster. I really just like galaxies in general, and I really enjoy the detail I get on the closer ones with the depth of my large telescope.
Is astrophotography expensive?
I suppose “expensive” is relative, right? It would seem expensive to someone who does cross stitch, but not to someone who races alcohol dragsters. It’s somewhere in between. 🙂
What should I do if I want to get started in astrophotography?
I would suggest a book that is a very good overview of what it takes and how it works: The Deep-sky Imaging Primer, Third Edition
Also, I would suggest perusing the Beginning Deep Sky Imaging forum on Cloudy Nights. There are many topics covering all aspects of astrophotography and many helpful people that can assist you in questions and decisions.
A new option that I would highly suggest to beginners is the ZWO Seestar S50. This is a compact, affordable all-in-one telescope that you can control from a phone or tablet. It will perform the stacking of images in real time, letting you explore the universe and see objects in real time. It also presents the raw files to you so that you can learn to stack and process real astronomical data.
Are these pictures doctored?
Sometimes I get reactions that my images are “too good,” suggesting they are synthetic or heavily edited.
There is a lot of processing I perform on my images to make them look better. A raw image of a deep space object is mostly black with a few visible stars, as the dynamic range of the fields I take is very high. A process called stretching is used to make the dark parts brighter as viewed on a monitor. Since this is a non-linear modification of the data, the “truthfulness” of this technique is hotly debated. However, without some kind of stretching, you won’t be seeming much in the images.
The cameras I use are OSC (one-shot-color), which are designed for terrestrial use and have color filters designed to mimic the color response of the cones of our eyes. This makes my images mostly true color, as you would see them if they were bright enough to appear to your eyes as they are in the picture. There’s a lot of discussion about how the response of non-IR filtered cameras are not “true color,” as they no longer mimic the human eye in the red spectrum. With such a filter, though, it would take significantly longer to image hydrogen emission nebulae. The deep reds and cyans of emission nebula in my images are their, mostly, real color if they were bright enough to stimulate the cones of your eyes.
I use other techniques in my image processing, such as using a neural network-based technique to separate the stars from the background. This lets me really bring out the detail in the background without the stars becoming large, bloated, saturated messes. I also apply a non-linear process to reduce the spatial size of the stars, so that your attention is drawn to the deep space object and not the, sometimes overbearing, star field.
Local histogram equalization is another technique that I will use to increase the contrast of objects. This can really bring out detail in objects that are high dynamic range after stretching, such as galaxy cores or very bright and dim parts of nebulae.
As a finishing touch, I usually do increase the saturation of my image to increase color separation.
In general, yes, the pictures are doctored to an extent so that we can enjoy the natural rich detail in these objects using the limited image storage and display technology that we currently have. However, they are not synthetic, as I take great care to simply enhance the data that comes from my telescope to see all that it has to offer.
I like your pictures, can I use them?
Yes! You are more than welcome to download any media from this website for your own enjoyment, such as screensavers or desktops. I suggest that you click on any image to view the full resolution version.
If you would like to use any of my images for non-commercial purpose, they are released under the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. If you would like to use them for a commercial purpose, please contact me from the Contact Page.
