www.cloudynights.com/Observation/suburb.htm
A mediocre sky and modest telescope are little hindrance to enjoying and having rewarding deep sky experiences. Today's generation of amateur astronomers face numerous sources of difficulty and temptation. The convenience of being able to observe from one's backyard is often overshadowed by the plague of light pollution, thus leading many to reserve serious deep space observation for dark sky outings or star parties. Furthermore, for many amateurs, aspirations of obtaining a premium quality telescope can diminish the desire to make use of lesser instruments. Dark skies and instrument quality are but two of many factors erroneously attributed to successful deep sky observation. As a testament to this, with typical suburban skies and a four-inch (102mm) achromat refractor, I have routinely observed finer detail in deep sky objects than many who make casual use of an eight or even ten-inch telescope. Although common knowledge tells that the vague spiral arms of M81 - left - require large aperture to be seen, careful scrutiny with a four inch (102mm) refractor can yield hints of the arm features. The mottled form and dark lanes present in M82 - right - can be glimpsed without much difficulty using a telescope as small as 3 inches (80mm). Dealing With Light Pollution As many amateur astronomers know, there are two forms of light pollution: sky glow and glare. The former, sky glow, is usually more difficult to control, but has less direct impact on observing than the later, glare. Sky glow has its source in wasted lighting that extends upwards from improperly shielded fixtures. Lobbying local officials or power companies can lead to some improvements, but the best method of reducing sky glow is to promote greater community awareness. Fortunately, organizations such as the International Dark Sky Association (IDA) provide amateur astronomers with tools necessary to combat light pollution. Glare can be easier to avoid than sky glow, but is often more intrusive for suburban astronomy. Glare is the unwanted light that comes from immediate sources: such as a neighbor's security light or a nearby streetlight. Fortunately, talking with a neighbor or contacting your power company to provide a shield for the streetlight can lend excellent results in reducing or removing the glare. In the event that the source of the glare cannot be diminished, there is still hope. If your observing location suffers from unavoidable glare, scan your location for shadowed areas that offer a view of the sky. Using a large beach-umbrella can create temporary shadowed areas. Simply take the umbrella, plant it into the ground between you and the unwanted light source, and open it: instant glare shield. Technology provides some potent weapons against light pollution as well. Light pollution reduction filters offer outstanding ways to improve the view of faint nebulae through even the worst light pollution. Broadband filters offer limited visual image improvement. Most would agree that the best single light pollution reduction filter is a Narrowband. Companies offering such filters include Lumicon, Orion, and Meade. It is critical to note, however, that in my experiences light pollution filters are successful almost exclusively in the observation of nebulae. Star clusters and galaxies seem to have very little image improvement when using these filters. Equipment & Improvements Although many amateurs desire to own one (or several) premium quality instruments, a principle fact to remember is that the best instrument for astronomy is the one utilized most often. For my observing style, I have found that a four-inch achromat refractor on an equatorial mount provides for the best combination of portability, affordability, and image sharpness. Regardless of your choice instrument, the principle factor in successful deep sky observing from a suburban location is contrast. Contrast can be lost to equipment if the optical tube is not fully closed. This problem tends to occur only with reflectors, usually around the focuser. If you can see gaps between a reflector's focuser and the optical tube, then that is a source for degrading contrast. Fortunately, some black electrical tape (for a quick fix) or some tinkering can cure this flaw. Any improvement in an instrument's ability to keep stray light outside of the optical path will be of benefit to suburban deep sky observing. Although modern wide field oculars state their supreme contrast, under field tests, I have found that simple optical designs virtually always win out over the wide field eyepieces in terms of subtle contrast. The best eyepiece for image contrast and sharpness is undoubtedly the venerable orthoscopic. Unfortunately, these are more difficult to find these days, but University Optics totes a full line of these excellent oculars (and at very reasonable prices). In honesty, there is no single eyepiece type that can provide everything needed for the most successful deep sky regimen. Wide field oculars are great for observing extended objects and surrounding star fields while orthoscopics offer the ability to hone-in on specific details to the best advantage (more on eyepiece usage in the "Techniques" section of this article). Final equipment considerations are to be had as comforts. Extended observing requires that you be comfortable, so a stool or chair is a great accessory to have handy. I have also found a rugged army-issue blanket to be great to place on the ground beneath the telescope, so that I can lay out my charts and eyepiece cases without fear of loosing something in the grass or getting the charts damp with dew and dirt. Finally, a pair of binoculars can be useful for tracking down specific stars for star hopping (if you do not use a computerized telescope). My favorite binoculars are a humble pair of vintage Sear's 8x40's. Techniques for Effective Observing Though factors such as your sky conditions and equipment can have some impact on the success of your observing program, the principle element that dictates your observing is techniques. By developing good techniques, you are guaranteed to find more detail and greater satisfaction in any area of astronomy observation. Generally, the following outlined method has yielded incredible results for my observing sessions. Depending on your enthusiasm, patience, and skills, your methods may differ. What follows might be a guideline, but it is essential that you develop a technique that works for you. Sketch surrounding star field - Sketch outline of object - Sketch details - Wait and sketch more details 5. Experiment with different eyepieces & barlows - Add any additional details After using equatorial, alt-azimuth, and modern computerized "Go-To" telescopes, I have found that a non-computerized equatorial telescope gives me the most enjoyment in locating and observing objects. In my opinion, half of the fun in astronomy is tracking down the object you wish to view. Also, I suspect that the time-spent star hopping allows the eyes to better adjust to the particular lighting conditions present (when compared to the automated go-to telescopes). Regardless of what type of system you observe with, be sure that you have located the object before proceeding. Compare the star-fields surrounding the object to a good star atlas: even modern computerized telescopes can have some error in their positioning. Patiently confirm and reconfirm that you are centered at the right area: if you are, simply breath steadily and stare at the area where the object should be located. As dim photons of light build in your eye's mind, the object may glimmer into view. Averted vision is difficult to teach, because it can vary per individual. For averted vision, shift your eye's focus from where the object should be to either side of the object. Since this forces the light from the dim object to strike the more sensitive portions of your eye, it may become detectable. Spend time developing your averted vision - it is by far one of the most significant and useful tools in deep sky observation. If you can see the object well with averted vision, try to spend time staring at the object with dire...
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