Deerfield Astronomy.Net

Part 1 – Making the Mask

Grey January skies with light snow, temperatures around 19°F or -7°C, a perfect time to finally make a Bahtinov mask for the 6” refractor used in my astrophotography endeavors.  For the last several years I’ve been depending on my old, trusty, reliable Hartman Mask when attempting to achieve that perfect focus needed for good images.  Although I’m making the new Bahtinov mask, I plan to keep my trusty Hartman on my equipment list.

I’ve wanted one of these focusing devices for a while now so today I decided to make one instead of buying.  Very helpful to this process is David Polivka’s website AstroJargon.Net which supplies an excellent mask template generator.  Plug in your telescope parameters which determines your focusing mask size, hit the generate button, and whala, the program creates a .svg file of your template mask.

In order to print the mask you’ll need software capable of reading the .svg file.  Scalable Vector Graphics (SVG) is a family of specifications of an XML-based file format for describing two-dimensional vector graphics, both static and dynamic (i.e. interactive or animated).  There’s a wide variety of software available to edit and print these types of files.  Here is a list of .svg editors which are both open source and commercial. After choosing your software, print the template at the proper scale so it fits your scope.  Some programs may try to scale the image to fit a standard 8.5"x11” size paper.  Depending on the size of your mask, you may have to print the mask in two sections and tape them together.

As seen in the photo to the right, after printing my mask template I attached it, using blue painters tape, to a piece of 8”x8” heavy card stock, black on both sides.  With a razor knife and a little patience, the mask began taking form rather quickly.  After completing the cutting a trip to the local sewing goods superstore provided me with a sewing hoop of the appropriate size to fit my lens hood.  The hoop was glued to the card stock and the inside edge lined with felt weather stripping.  I also glued a scrap piece of curved foam-core board on one side for handling purposes.  A final coat of black paint, to help the card stock resist moisture, finished the assembly.

Coming Soon… Part 2 – Using the Mask…

The day is blustery with a slight chill in the air; winds appear out of no where and fade away as silently as they appeared while moving the trees limbs back and forth.  Summer has run its course and is definitely over.  As human beings we are surrounded by biological rhythms of nature; a set of common cycles shared by all inhabitants of our planet.  Mostly self-centered by nature, we focus on our own personal needs and thoughts, ignoring these cycles.  As I sat in my backyard observing nature, it occurred to me that natural cycles surround and consume us all, all of the time. While listening to birds chirping back and fourth, it dawned on me there is an amazing amount of cycles created by their communications alone.  We as humans share a great deal with our fine feathered friends, whether it is realized or not, circadian rhythms of life and nature surround, define and control both of us in infinite ways.

As earth orbits our sun, the seasons progress and earth completes another of its annual cycles.  Since times before the dinosaurs and our ancient ancestors, these rhythms of life have controlled all creatures from microscopic cells to the largest of mammals.  According to Merriam-Webster’s dictionary, one definition of a cycle is; “a course or series of events or operations that recur regularly and usually lead back to the starting point.”  Seemingly endless cycles of life and death, day and night, hot and cold, time, seasons, weather, even emotions, just to name a few, provide us with the predictable unpredictability that we call, “Life on Earth.”

It doesn’t take very much effort to detect and observe natural cycles.  One of the biggest challenges that prevent our observations is our ability to disengage from the 24/7 lifestyles most of us live. Disengaging from this frantic world is imperative so that one might actually focus on what’s usually considered the background noise.  Usually invisible, this background noise constantly surrounds us and feeds our senses continuously whether it is obvious or subliminal.  Unless we are somehow forced to slow down, take notice, and observe, most of this information passes us by. 
You don’t have to travel to exotic destinations in order to observe these cycles.  In my case, I journeyed no further than my own backyard.  Being fortunate enough to live in a house with a larger than normal yard, approximately ¾ of an acre in size, we are surrounded by nature. There are many beautiful, mature trees that my father and I planted when I as teenager way back in the seventies.  As the leaves turn to colorful oranges, yellows, and reds, another summer season has come and gone.  The passing season reminds me of my dad and me planting these trees over thirty years ago.  He passed in 1987, and to this day I cannot view those trees without thinking of him and his influence on my life.  Passing at the age of 59, I can’t help think about if my own cycle of mortality will be the same as his or hopefully much longer.

Colorful leaves hang on to their hosts as long as possible before giving up their lofty positions after 6 months of loyal service.  The autumn rainstorm has left a grey and white sky, in addition to a soaking of over 2 inches of rain during the last 24 hours.  Left in the storm’s wake, dense, clean, fragrant, crisp air that is characteristic of the fall metamorphous.  Summer fades into the abyss of winter.  Another summer vanished, like some kind of yearly magic show, another year passes before my very eyes.

Squirrels engage in their annual ritual of gathering winter provisions of acorns and other foods to weather the approaching harshest season of the year.  In a case of “who said animals are dumb?” I actually watched squirrels harvesting acorns in an organized manner from the tops of our neighbors oak trees.  They chewed off little branches with acorns attached, letting them drop to the ground, and then gathered them from the ground for storage.  Thanks to farmers throughout the world worrying about their own set of growth cycles of their crops and the logistics of getting them into the supply chain for our consumption, we have it much easier than the squirrels.  Both wildlife and human alike must deal with the delicate balance of agricultural cycles of growth, harvest, storage, and consumption.

Like some grand experiment, all creatures are brothers and sisters existing in the same common Petri dish being fed by an endless amount of cycles.  We attempt to survive and prosper, all governed by the same set of natural laws and rules of periodicity.  If there is a beginning, the natural cycle dictates there will at some point, be an ending.  Life and nature are continuums of cycles with varying influences, frequencies, and amplitudes which affect humans, animals, the planet, our solar system, and even the universe.  No matter how different everyone thinks they are, we’re all the same in the eyes of the never ending natural cycles surrounding us.  Like a giant wheel in the sky, the annual movements of the stars and constellations guide us through our yearly progression around the sun, leading us from season to season.  Whether we choose to pause and observe or not, the wheel in the sky keeps on turning, taking us to our destiny.

Like most amateur astronomers, you’ve probably thought more than once about building a permanent home for your telescope setup.  I’m in the process of contemplating a small backyard observatory and during my research phase discovered many creative designs.  Look at some of the very creative ways fellow amateur astronomers conquered the challenge.

 
• Ptolemy’s Cafe
 
• Arrakis Observatory
 
• Blackberry Observatory
 
• Randy Brewer’s deck
 
• Massimo Caimmi
 
• Michael Caligiuri
 
• David Cash’s
 
• Dave Clifton
 
• Conlin Hill Observatory
 
• Lookum Observatory
 
• Osservatorio Mazzotti
 
• Oak Hill Star Shed Observatory
 
• Oil Region Observatory
 
• The Outhouse
 
• Passion Du Ciel
 
• Possum Observatory
 
• Norman Reynolds
 
• Ryder Homestead Observatory
 
• Frank J. Shepley
 
• Split Rock Observatory
 
• Star Deck Observatory
 
• Star Watcher Observatory
 
• Don Stefanik
 
• Sunflower Observatory
 
• Maury Childs Observatory
 
• Bill Arnett’s Observatories List