Because a telescope mirror focuses light, the mirror's surface must be polished to the astounding accuracy of a small fraction of the wavelength of visible light, a mere millionths of an inch. The feel of the mirror in my hands while I shape it is sublime - time ceases. Designing and building the telescope to hold the mirror involves disciplines from mechanics to software. With such a telescope, the Antennae Galaxies show beautiful tidal streams along with a phantom galaxy near the edge of the eyepiece. To observe objects, I sketch from the eyepiece.
A beautiful telescope brings joy: crisp astonishing images across a range of magnifications. I work on fast and ultra-thin mirrors for 'feet on the ground observing' with lightweight telescope structures. Using design patterns and morphological analysis I unfold the telescope design informed by my observations. I honor masters who have gone before and anticipate those to come.
Seneca said that, "There will come a time when our descendants will be amazed that we did not know things that are so plain to them. . . . Many discoveries are reserved for ages still to come, when memory of us will have been effaced. Our universe is a sorry little affair unless it has in it something for every age to investigate . . . . Nature does not reveal her mysteries once and for all." (Natural Questions Book 7, c. first century)
Russell W. Porter, founder of Stellafane wrote, "For it is true that astronomy, from a popular standpoint, is handicapped by the inability of the average workman to own an expensive astronomical telescope. It is also true that if an amateur starts out to build a telescope just for fun he will find, before his labors are over, that he has become seriously interested in the wonderful mechanism of our universe. And finally there is understandably the stimulus of being able to unlock the mysteries of the heavens by a tool fashioned by one's own hand."
Robert Burnham, Jr. wrote, "The appeal of astronomy is both intellectual and aesthetic; it combines the thrill of exploration and discovery, the fun of sight-seeing, and the sheer pleasure of firsthand acquaintance with incredibly wonderful and beautiful things."
Stephen James O’Meara wrote in his third book in the Deep-Sky Companions series, "As for now, I am living under natural skies. I feel like an explorer who has been given an opportunity to study the last great tract of rainforest. I spend my time documenting everything I see, because I know that there will come a day when everything I see will no longer be regarded as reality but as a myth. I hope that day never comes, but until it does, I’ll be out there seeing what I can see."
“The difficulty lies not so much in developing new ideas as in escaping from old ones.” — John Maynard Keynes “Life is trying things to see if they work.” – Ray Bradbury John Dobson brought us the Dobsonian telescope: big aperture bright views. TeleVue brought us coma correctors and wide angle eyepieces. My vision is developing thin fast meniscus mirror technology so that the Dobsonian 16 inch F5 with its one degree field of view morphs into either a:
Check out what I can see with high etendue telescopes. Listen to an interview of me on the Actual Astronomy Podcast, June 2023. Watch my presentation on software enhancements to my Ronchi Calculator:
Class notes for the 16F3 master meniscus mirror making class. | |
Making two 42x5/8 inch [1067x16mm] F2.8 thin meniscus mirrors. 'The answer is 42', my Oct 2022 presentation for the Altaz Initiative. | |
My 7th thin fast meniscus mirror, 20.25x3/4 inch [514x19mm] F2.9, weighs 23 pounds [10kg], slumped from BVC (Black Vitreous Ceramic), a low expansion laminated glass. This is the final tuneup before working on the 42x5/8 inch [1067x16mm] F2.8 thin meniscus mirrors.
Before the 16.25x3/8 inch [410x10mm] F2.9 meniscus blank became an option, I had ordered a 20 inch meniscus BVC blank. But it failed when I ground through the lamination on the backside. While waiting for the replacement blank, the 16 meniscus blank became available. I completed the mirror quickly and built the mount quickly too (a couple of months total). It is a wonderful scope perfect for outreach and those times when I can't easily haul the 30x5/8 inch [760x16mm] F2.7 telescope. Besides the mirror making tuneup, I wondered if I could make a 20 inch to be like the 16 inch in its portability and quick setup. I enhanced my Ronchi Calculator with the software nulling feature which I used to make the mirror. | |
2022 My sixth thin and fast meniscus mirror, a 16.25x3/8 inch [410x10mm] F2.9 that weighs but 7.5 pounds [3.5kg]; follows in the footsteps of David Davis' and Rob Brown's similarly sized mirrors.
This is proving a spectacularly successful scope. Super portable for its size, perfect star test optics and immune to falling evening temperatures. This is my third 3-axis mounting. How I made the mirror and scope with a total weight of 25 pounds [11kg]. | |
2021 Having finished twin 30x5/8 inch [760x16mm] F2.7 mirrors (slumped beautifully by David Davis), I designed and built a lightweight 3-axis telescope that weighs a total of 100 pounds [45kg]. After silvering the mirror under Howard Banich's guidance, I am achieving unprecedented views.
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2021 I finished my effort to consolidate my telescope design software and articles into the interactive NewtDesigner. | |
2018 I lept into large thin meniscus mirrors, completing the 25x1/2 inch [635x13mm] F2.6, a slumped mirror blank from Greg Wilhite. I designed a lightweight 3-axis mounting to go with the lightweight mirror with a total weight of 75 pounds [34kg].
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2016 embolden by recent observations, I tried my luck on IFNs... 2018 can I see IFN with large aperture? Is etendue a consistent explanation across apertures? 2019 can I see IFN with binocs/unaided-eye? 2022 does a 30 inch telescope show detail in IFN? 2023 OIII clouds: a new class of astronomical object? |
2013 I followed with 6 inch F2.8 and 10.5 inch [267x19mm] F2.7 mirrors (another Richard Schwartz slump) to gain more experience. Major success optically and observationally. | |
2008 I finished the slumped 13.2x1 inch [335x25mm] F3.0 mirror blank that Richard Schwartz sent me; I am so happy with the scope optically, mechanically and observationally. | |
Early 2000's looking to make lightweight mirrors, I reasoned that perhaps the difficulty of making stiff cellular mirrors could be replaced by keeping only the face plate and building an appropriate mirror cell behind it. Richard Schwartz, Greg Wilhite and David Davis sent me thin meniscus mirror blanks.
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In 2003 I finished construction of a new ultralight design that I call the Trilateral or TriDob, based on the use of triangles in the upper end, the trusses and the rocker with altitude bearings. | |
I began developing an open source software and hardware computerized control system for telescopes in the mid 1980's that incorporated software and hardware innovations. Pat Sweeney designed a PCB in the late 1990's. And in 2000 my wife Barbara and I incorporated BBAstroDesigns, Inc. to sell kits and finished boards. I finished my 20 inch fully computerized telescope in 1994 with which I took some early CCD images. | |
My Dobson era begin in 1981 with a bang: a 24 inch f5.5. I built my first grinding machine and worked on 20 inch f/4, 20 inch f/5, 24 inch f/6, 25 inch f/6 and 30 inch f/4 mirrors. | |
I began in the 1960's and 1970's by building Palomar 200 inch inspired horseshoe mounted reflectors equipped with homemade cold cameras, processing black and white Tri-X negatives and color Ektachrome slides in my darkroom. |
Newtonian reflecting telescope designer...
...what does a telescope do
...how does a telescope work
......scope performance as a function of exit pupil
......focal length and aperture
......focal ratios
......apparent size and image size
......field of view
......four magnifications
......ray tracing
......the eyepiece
......the eye
......diffraction and the Airy disk
......etendue
......high etendue telescopes
......low magnifications
......the ideal telescope
...Richest Field Telescopes
...collimation
...seeing and turbulence
...telescope value
...field curvature
...the nature of telescope design
...folding and sliding scopes
...who invented the reflecting telescope
...helpful formulae
Visual calculator; observing notes
...visual units of measurement
...magnitude scope
...Bortle scale
...object types
...object brightness
...how faint
...aperture vs light pollution
...how to observe
...binoscopes
...night vision devices
Eyepieces
...magnification
Coma corrector
Diagonal designer
...secondary size experiment
...diagonal offset study
...optimize diagonal size
...two unknown optimizations
...off axis mask
Spider and diffraction
Mirror cell
Focuser and baffle designer
Optical layout, baffling
Lowrider layout, baffling
Binoscope
Center of gravity
Tube types
Mount types
...telescope vibration
...ballscopes, take 2
...the Earl of Crawford's tracking arm
...three axis mounts
...the Holcombe mount
...the Morse equatorial to altazimuth transformer mount
Rocker
...friction of movement
Flex rocker
Equatorial table
...omni latitude table
...turret equatorial table
...tilt tracking table
Export and import designs
...30 inch design
...proposed 30 inch binoscope design
Oregon Star Party...
...2023 Oregon Star Party
...2019 Oregon Star Party
...2018 Oregon Star Party
...2017 Oregon Star Party Eclipse Edition
...2016 Oregon Star Party
...2015 Oregon Star Party
...2014 Oregon Star Party
...2013 Oregon Star Party
...2012 Oregon Star Party
...2011 Oregon Star Party
...2010 Oregon Star Party
...2009 Oregon Star Party
...2008 Oregon Star Party
...2007 Oregon Star Party
...2006 Oregon Star Party
...2005 Oregon Star Party
...2004 Oregon Star Party
...2003 Oregon Star Party
...2002 Oregon Star Party
...2001 Oregon Star Party
...1999 Oregon Star Party
...1998 Oregon Star Party
2012 Waimea Hawaii AltAzInitiative
2010 RETA Spain