Expectations through the Telescope

orion-nebula-02

Astrophotography is the single largest buzzkill to the hobbies of astronomy and stargazing.

You look up into the night sky.  You see dozens to thousands of stars, depending on your area’s light pollution.  You look at some of these objects through, say, binoculars.  They will appear a little larger, but mostly you will be frustrated by the jittery view since you cannot steady your binoculars.  You may also look through a telescope, and if the conditions are ideal and you can pinpoint a known object, like a planet, you will see…something very, very small.

You look at a well-known deep sky object like the Orion Nebula.  Do you except to see something colorful and majestic?  No matter the aperture of your telescope or location on Earth, what you will see with the naked eye amounts to a mostly monochrome view of the major structural components for this famous nebula.

So why, you may ask, is there such a gap between the grandiose pictures you see in textbooks and on the Internet and what you see live through your humble telescope?

The answer is twofold.  First, because all these celestial objects are really far away, the light that we get from them is really, really faint.  You can understand this in relative proximity.  First, consider the Moon.  At a little over 200,000 miles away, it is like a guy sharing the same couch with you as far as the universe is concerned.  It does not take much effort to see great views of the Moon unaided, with binoculars, or a telescope.  It fact, there is so much light coming from the Moon, you are probably better off with a Moon filter/dimmer on a telescope to reduce the amount of light in order to ascertain better contrast.

Now consider the planets.  They are tens and hundreds of millions of miles away, several orders of magnitude farther that the Moon.  Their light is far fainter than the Moon’s, not to mention appearing far smaller.  The unaided eye and most binoculars will see Venus, Mars, Jupiter, and Saturn as bright points of light, resembling stars.  Through a telescope and depending on aperture and conditions, you should be able to make out features on these planets (minus Venus which will be washed out by the Sun’s brightness).  It will not all come at once and practice viewing these objects will train your eye to see more detail.

Now think of deep sky objects.  The closest of these objects are measure in thousands of light years.  The farthest, galaxies, are hundred of millions of light years and much more away.  That we get any light from their drops of photons reaching Earth and punching through her atmosphere is remarkable in its own right.  Still, the photons are limited in availability, and our eyes, untrained to see objects trillions of miles away, only make out the weakest of details.

The second reason for image disparity is astrophotophy post-processing.  The spectacular images we see of nebulae and galaxies are the results of very long telescope camera exposures on smooth equatorial mounts (which align to the rotation of the earth) followed by a lot of image processing with both dedicated and general photography computer programs.  The idea is that long exposures will capture a lot more photons than we can see at once, and you then clean up the resulting images, filled with all those extras photons, in post-processing.

This Youtube demonstration shows how one astrophotographer made an image of the Andromeda Galaxy go from bland to professionally stunning:

Despite the wonders of post-processing, I think these end images, without the proper understanding of how they are made, do a disservice to the beginning astronomer.  A beginner will be immediately disappointed that he cannot see the Orion Nebula is all its true (post-processed) glory.  Worse, the beginner astronomy may take the folly step of wanting to jump straight into astrophotophy, spending thousands of dollars on equipment, which still will not yield good results if you do not understand how to use them.

Based on my own experience this past year, I believe the best approach for the beginner astronomer is to take stargazing step-by-step:

  1. Learn how to track the phases of the Moon
  2. Learn the paths of the planets (which follow the same general path as the Sun)
  3. Learn about the major stars and constellations, and how to track them season to season
  4. Get a good pair of binoculars – you’ll be amazed at how many more stars you can see through their clear wide-field views
  5. Once you feel comfortable with the above tasks, then you should investigate getting yourself a good telescope!
  6. Whether you get a refractor, reflector, or some variation, learn how to use your telescope to get the most out of it.  This will take time.
  7. Later on, once you are comfortable with your telescope, you may begin to explore astophotography
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