How To Begin Astronomy On A Budget
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I'm sure that many of you just getting interested in the hobby of astronomy,
wonder if that small telescope you bought (or are thinking about buying) will
see any details on the moon or planets. I put this web page together to show
that even a very modest-sized telescope, if of reasonable quality, can see and
even photograph more lunar and planetary detail than you'd likely imagine.
I took on the challenge of getting these images through a 60mm f/17
refractor telescope to prove a point. I've seen many advice articles on what
telescopes beginner astronomers should buy, and while there's always some good
points presented, it seems to me that the things that can be viewed through a
60mm refractor are often understated. So I took these images to show not only
what you can expect to see with such a telescope, but what you can even
photograph if you have the inclination, some time, and a bit of patience.
If you want to start an astronomy hobby on a budget, and maybe even do a bit
more than just observe objects, let this web page give you some
inspiration.
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Start With The Tripod Mount And Telescope
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I put the telescope at left together on a very meager budget. The Pipe Fitting Tripod only cost
about $50 and a bit of elbow grease. Click on the indicated link to see how you
can make one.
The 60mm
Refractor Project only set me back about $125. It is made from
new old stock optics parts, obtained from the sites listed at the 60mm Refractor
Project link. The telescope I made is a 60mm refractor of the old
school design, with a focal ratio of f/17. That makes the instrument an
excellent performer for lunar and planetary work, even though only 60mm in
aperture.
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Keen Designs T-Shirts and Mugs
If You Want To Take Pictures -- Add A Camera
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If you want to use your telescope for more than observing, you can get
started inexpensively in a number of ways. The pictures shown later on this web
page were taken with a Celestron NexImage astro-camera, which cost me about
$100. In the image at left you see my Celestron NexImage web cam and Barlow
lens inserted into the telescope's focuser.
You can see that I removed the star diagonal, inserted the Barlow, then
inserted the camera. The Barlow doubled the magnification of the telescope to
give me high resolution images.
If I want wider field images, I insert the web cam directly into the
focuser, leaving out the Barlow lens. |
You can probably get into astrophotography at an even cheaper price. You can
make your own Web Cam
Astro-Camera as I did. It works exactly like the Celestron NexImage, and
might cost you even less. You'll need a bit of construction skill and possibly
a camera adaptor.
You can even take moon photographs with just a typical digital camera. I
show how to do that on the Digital Camera
Mount web page. You can also get some good shots by just focusing the
telescope on the moon and holding a digital camera up to the eyepiece, as shown
at the bottom of the 60mm Refractor
Project Photographing planets with a digital camera requires a model that
lets you turn off the auto focus and auto exposure features. Frankly, if
shooting planets is your desire, you want to go beyond a hand-held camera.
The Celestron web cam came with the handy image stacking program RegiStax.
If you make your own web cam astro-camera, you can get RegiStax and install it on your
computer.
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And Now, Some Photographs
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The following photographs were all taken with the illustrated 60mm telescope
and the Celestron
NexImage web cam. Note that the telescope was mounted on the heavy-duty
pipe-fitting tripod. That tripod has neither a clock drive nor slow motion
controls. However, it is extremely sturdy and holds the telescope at any given
position with absolutely no vibration.
I lightly tapped the telescope in desired directions to make minute
adjustments in the pointing angle, then used my laptop to collect film strips
(.avi files) with the Celestron NexImage. While the target drifted through the
field of view as the earth rotated, the shutter speed of the NexImage was
sufficient to capture sharp images. The fact that each successive frame of a
file was shifted in position was taken care of by processing the files with the
RegiStax software program that came with the Celestron camera.
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A sturdy mount is most critical for photographing objects at high
magnification. You'll do better with a modest telescope on a solid mount than
with a bigger telescope on a wobbly mount.
I used 620x480 resolution for the image capture. Images were aligned and
stacked using the RegiStax. By choosing a specific area for alignment before
stacking, I was able to extract those portions and enlarge them a bit while
still achieving good results. For the lunar images, I show both the full-sized
stacked images and an enlarged portion. These give a sense of what can be
viewed through a good quality 60mm refractor.
The moon images each consist of between 20 and 40 stacked frames. The
Jupiter image has about 150 stacked frames.
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Moon, Plato Region. 60mm f/17 telescope with Celestron NexImage camera.
Click To Enlarge
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Moon, Alpine Valley, 60mm f/17 telescope with Celestron NexImage camera.
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Moon, Eratosthenes Region. 60mm f/17 telescope with Celestron NexImage camera.
Click To Enlarge
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Moon, Eratosthenes crater, 60mm f/17 telescope with Celestron NexImage camera. At times I've struggled to see those 3 mountain peaks in Eratosthenes even with my 6 inch reflector. But here, the 60mm captured them nicely. For scale, Eratosthenes is 36 mi in diameter.
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Moon, Straight Wall Region. 60mm f/17 telescope with Celestron NexImage camera.
Click To Enlarge
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Moon, Straight Wall, 60mm f/17 telescope with Celestron NexImage camera.
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Moon, Tycho region. 60mm f/17 telescope with Celestron NexImage camera.
Click To Enlarge
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Moon, Tycho crater, 60mm f/17 telescope with Celestron NexImage camera.
Notice the small peak next to the central mountain peak.
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Moon, Clavius region. 60mm f/17 telescope with Celestron NexImage camera.
Click To Enlarge
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Moon, Clavius crater, 60mm f/17 telescope with Celestron NexImage camera.
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Jupiter. 60mm f/17 telescope with Celestron NexImage camera. In this
inverted image, the NEB (brown belt) is easily seen. You can also just
see a shaded region where the SEB usually is visible, but not in this 2010
image when the SEB all but disappeared. Also visible is the NTB and the
darkened polar caps (see Observing Jupiter).
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Jupiter. 60mm f/17 telescope with Celestron NexImage camera. This is my
best black and white image, stacking about a dozen of the best frames. This
is more like what is actually seen through a 60mm telescope.
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Summary
You might wonder why it's good to stack images. Because it gets rid of the
pixelization that tends to be visible in individual frames, which makes the
images look grainy. Stacking also helps reduce the image variations caused by
the scintillating atmosphere. Can it create more detail than actually is
visible? No, it cannot. If the telescope doesn't deliver details beyond a
point, stacking won't either.
Can you really see all the detail shown in these photographs with a 60mm
telescope? In a word -- yes, if it's a quality one. There are differences
between what can be seen in stacked images like these and the actual telescope
view. Looking live through a telescope, one can see more detail -- yes, that's
more detail. The atmosphere has moments of clearing that give the
viewer very crisp views, if only for short intervals. This is very difficult
to catch on camera.
On the other hand, by post processing images, one can adjust the contrast to
bring out details that may not be easily seen with the eye at the telescope.
For example, notice the brown North Equatorial Belt on the Jupiter photograph.
Through a small telescope, color such as this isn't perceptible by the eye,
though it is through larger telescopes. But the color is there, and the camera
picks it up. In the 60mm, the NEB is quite visible, but it looks dark gray
instead of brown.
So if your budget or need for portability demand you consider a 60mm
telescope, just pick a good one and you'll be happy. Consider browsing eBay for
vintage 60mm telescope, many Japanese made. Look for brands such as older
Tasco, Sears, Towa, Unitron, Polarex, Mayflower, Jaegers, Edmund, or Monolux.
These brands are some of the fine brands made yesteryear, before the 60mm was
considered to be primarily a kid's telescope.
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