Let’s face it, we look at colorful space-shots taken by the Hubble and drool. We see hordes of images taken by amateur astronomers on the web or in books and folks start getting tempted to thinking that maybe they can take such great shots as well! After all, you just got that nifty new telescope and the pictures on the box showed some awesome looking photos. So maybe we can just take this little 50mm telescope we got into the backyard and…
OK, a reality check here. Astrophotography can be lots of fun, and it can be very satisfying. It is also an incredible learning experience and with todays digital camera technology it is more versatile and satisfying than ever before.
But that does not change the fact that doing serious astrophotography involves a lot of:
Time? Well a lot of astrophotography involves long exposure shots, or lot and lots of short exposure that get ‘stacked’ on a computer. These shots need to be undisturbed, and yet even if your camera is in a place where it will be unmolested you can’t just walk away to grab coffee during a long-exposure shot. There are going to be adjustments to be made. Some folks have spent hours and hours just getting a single shot, some spend hours and come up with nothing worthwhile.
Money? Even if you already have a SLR or DSLR camera you are going to need a telescope mount that is much bigger than most beginner’s models. You may also need a special digital astrophotography camera for advanced shots. There are also filters, tracking scopes, special eyepieces, software, and a horde of other materials. Some of them are optional for astrophotography, but some are not.
The Test: Piggy-Back Photography.
Piggy-Back photography is what we consider an acid test for people first trying astrophotography. It can be done with a lot of the smaller equatorial mounts and a camera that has control of exposure time. We like to consider that if you cannot handle piggy-back photography you might want to re-think astrophotography.
You will need a telescope with an equatorial mount – a decent one if you can. The smallest of mounts probably won’t work well but some of the larger beginners models can cut it. You will also need a motor for the telescope mount so it can track to the night skies. Almost all telescopes with equatorial mounts have what is known as a piggy back screw on one of the tube rings. This is a screw that you thread the bottom of your camera onto to set everything up. Here is an example of a telescope with a camera in the piggy-back position.
Take this setup outside and aim it at a region of the sky. Set things up so that your telescope is pointed dead-on with a star (this will be called the guide-star). Crank the f-stop as open as it will go, open the shutter and let it take a shot for about 10-20 minutes for starters. Make sure to check the guide star in the eyepiece and make sure it stays in place. Adjust the motor speed carefully to ensure this.
So how did that go? Probably not well your first time. There are a horde of things that can go wrong – bad tracking, bumping the mount, light pollution washing out the image (a big one), finicky camera. This is all a part of astrophotography. Look on the bright side: odds are you used a digital camera so you can at least see your results right away. Imagine if you had to wait for the film to develop to try and figure out what went wrong.
Now keep in mind: Failing is a part of learning. You can see from your images and do a little detective work to see what was wrong. If you tried to shoot the Moon long exposure odds are it will wash out everything (the moon needs very little exposure time). If you had some heavy light pollution in your viewing area that will likely give the photo a lot of haze. If the telescope mount did not track the shot will be streaky or blurry.See if you can fix the problem and try another shot.
The point of piggy-back mount photography is to get some experience with the real thing without a heavy investment of time & money – OK at least money. Like we said we consider this method a way of testing you to see if you will actually enjoy astrophotography. If you find this experience too frustrating and annoying you might not want o invest the time & money in the heavier duty stuff.
But if you had fun solving the problems and got results you are satisfied with, we’ll cover the other methods of astrophotography (and the stuff you’ll need) in part 2!