Astronomy for RVers – Intro to astrophotography – Interested?

By Chris Fellows, Serenity Mobile Observatory

Should you jump into this rabbit hole?

So, you bought yourself a nice little telescope and observed a few celestial bodies with your own eyes. You were fascinated but also a little disappointed at what you saw. After all, all these gorgeous photos you see on the Internet of the Orion nebula, Jupiter, or even distant galaxies are sharp, bright and full color. What you see at your eyepiece is fuzzy, faint and gray. What the heck is going on?

The explanation is quite simple: Your brain can detect photons (light) through the lens of your eyes but it can’t store them. Visual observation is like water through a straw, it just comes in one end and drips out the other, and once it has left the pipe it is essentially gone forever. Conversely, adding a camera to your scope is like adding a bucket to the end of the straw. You can collect the drops and it takes on a completely different form. It now has volume, weight and texture. In this article we will add the bucket.

The first thing I want to say about this is that if you make the decision to get into astrophotography you are essentially taking the red pill – “you’ll stay in Wonderland, and I’ll show you how deep the rabbit hole goes.” —The Matrix.

The truth is, astrophotography is hard. You are attempting to capture individual photons from moving targets. In many cases those photons have been traveling for millions of years. There is noise everywhere, sky glow (light pollution), sensor noise, optical distortions, and just plain old weather conditions that have to be understood and corrected for.

It is also not cheap. Although you can get started with just a telescope and a smart phone, you will quickly want to upgrade. My imaging setup is now around the $10,000 mark, and I am nowhere near a top-shelf amateur astrophotographer. My system consists of a large telescope, a computerized tracking mount, an automatic focuser, a 7-position automatic filter wheel, a coma corrector, and a purpose-made and cooled CCD camera. I also use a second telescope with a second camera feed into a laptop computer to guide my system while it is taking photos. The software alone was over $1000. Even with all that I am still chasing the dragon because I know I can do better.

Let’s start with the simplest (and cheapest) method: direct photography. This is simply pointing your camera at a target, say the moon, and snapping a snapshot. You should use a camera that you have control over things like shutter speed, ISO and gain. You should also mount your camera on a tripod to steady it and use a remote shutter release so you don’t have to touch the camera to take the picture. I looked on Amazon and found this setup for only $37! A universal smartphone adapter, an inexpensive tripod, and a remote shutter release will allow you to aim, focus and shoot simple astrophotographs.

The next step up is called eyepiece projection or afocal photography. In this setup you use a telescope with an eyepiece installed and instead of looking through, you point a camera at the eyepiece. You will obviously need a mounted telescope for this method but you will also need a way to attach your camera to the eyepiece. I found this simple universal smartphone eyepiece adapter gadget on Amazon to accomplish this task. You will still need the remote shutter release above but now you will be able to take closeup and detailed photos of craters on the moon and the bands of Jupiter. Depending on your telescope and mount cost you can do this type of photography for around $200.

The next level is prime focus astrophotography. Using this method you will need all the stuff used in the eyepiece projection method plus a tracking telescope mount, a DSLR or 35mm camera with a removable lens, an eyepiece adapter, and a “T” ring. The “T” ring is camera specific and the one I found on Amazon is for a Canon 35 mm camera. Make sure you find the one specifically for your camera make and model. Using this method you can start to get into some serious astrophotography but you are also starting to get into some serious money.

The cheapest tracking mount is going to run you about $500, a DSLR body will be at least $300 (new, but you can buy an older used one), and with the other items in this setup you’re looking at around $1000. The upside is now you can leave the shutter on your camera open much longer and collect more of those elusive photons. A non-guided setup like this can normally easily take 30-second exposures. I have a friend that, with very careful alignment, can push that to a couple of minutes. This gets you into a whole new class of much dimmer objects to photograph. Things like the Orion nebula, the Andromeda galaxy and globular clusters are now well within your reach.

From this level it is all about adding doo-dads to improve some aspect of your imaging sessions. A better tracking mount ($1500–$10,000), auto-guiding (several hundred to several thousand dollars), temperature compensating auto-focus ($100–$1500), a purpose-built astrophotography camera ($200–$10,000 or more).

You’ll also notice that I didn’t mention any specific telescopes here. A decent instrument can be bought for a couple hundred bucks, but you can also easily get into thousands of dollars for the scope.

Clear Skies,
Chris Fellows, Serenity Mobile Observatory

Find Chris on Facebook (or, if you’re lucky, at your campground). (Editor: Check out his amazing photos on his Facebook page!)

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