Deepsky Astronomy Museum
Showcasing telescope and other unique astronomy related items since its founding in November 2024
Telescope and Mount Collection
Astro-Physics 155 f/7
Alan Dyer reviewed the 155 EDF Astro-Physics Refractors in the 1993 September issue of Astronomy magazine in an article titled Big & Small. He states: “Optical performance of the 155EDF was impressive. It produced nary a trace of false color even on Venus. Equally impressive, this scope provided superb images as soon as it was set outside. Even in sub-freezing temperatures, image quality, though not perfect at first, was surprisingly sharp from the start. In cold weather, after a modest settle-down time of 30 minutes, in-focus star images were textbook Airy disks with a well-defined first diffraction ring and a trace of a second outer ring. There was no sign of spherical aberration, lens figure changes, heat plumes, or distorted Airy disks due to tube turbulence.”
Carl Zeiss Telemator
The Telementor and Telemator refractors are iconic telescopes that exemplify the precision engineering and craftsmanship of Carl Zeiss, a renowned German optics manufacturer. Carl Zeiss Jena, located in East Germany, was responsible for producing these telescopes during the Cold War era. The Telementor series was marketed primarily to schools, universities, and amateur astronomers, reflecting its dual role as an educational and observational instrument. The Telementor made its first appearance in May 1972 and quickly became a favorite among amateur astronomers, educators, and observatories.
The telescope features a 63mm cemented doublet with a focal length of 840mm, giving an f/13.3 ratio. This design has minimal chromatic aberration, making it ideal for lunar, planetary, and double-star observations. The Telementor came on the equatorial T-mount with a robust design that requires manual tracking. The Telemator added an electric clock drive, making the TM mount better suited for education. The Telementor originally came with a helical rear focuser. The later Telementor-II and Telemator have an internal focusing mechanism that moves the objective lens in the refractor tube.
The Telementor’s origins and legacy are tied to the Cold War divide between East and West Germany. Despite the geopolitical barriers, Carl Zeiss Jena telescopes gained a cult following worldwide for their optical quality and reliability. Today, the Telementor and Telemator are highly sought after by collectors and astronomy enthusiasts who appreciate their timeless design, optical quality, and historical significance. They remain a testament to Carl Zeiss’s expertise in crafting world-class optical instruments.
4.5” Dobbins
The Dobbins Instrument Co., a telescope manufacturing company, made more than 100 telescopes. The Dobbins Instrument Company started in November 20, 1979, and lasted until 1991. The Company was started by Thomas J. Dobbins (August 13, 1922 – November 9, 2002) and his son, Thomas A. Dobbins (Born: August 4, 1958). Dobbins Instrument Company was located in Lyndhurst, Ohio, Cuyahoga County. In 1992, the rejuvenated company went by the name A.R.O. Instrument Company, and lasted until 1997. A.R.O. Instrument Company was located in Coshocton, Ohio, Coshocton County.
The Dobbins refractor on display is 4.5” f/12.5 refractor on a Mark III motorized mount. The scope and mount were built in the 1980s.
Mark III Mount
The Dobbins Instrument Co., a telescope manufacturing company, made more than 100 telescopes. The Dobbins Instrument Company started in November 20, 1979, and lasted until 1991. The Company was started by Thomas J. Dobbins (August 13, 1922 – November 9, 2002) and his son, Thomas A. Dobbins (Born: August 4, 1958). Dobbins Instrument Company was located in Lyndhurst, Ohio, Cuyahoga County. In 1992, the rejuvenated company went by the name A.R.O. Instrument Company, and lasted until 1997. A.R.O. Instrument Company was located in Coshocton, Ohio, Coshocton County.
The Dobbins refractor on display is 4.5” f/12.5 refractor on a Mark III motorized mount. The scope and mount were built in the 1980s.
Dynascope 6” f/8
The Criterion Co. was established at 331 Church Street, Hartford 3, Connecticut, by Mr. John Krewalk, Sr. In time, it became the Criterion Manufacturing Company, Inc. His son John J. Krewalk (b. 1950) would, in time, come to work for the company too.
The first telescope offered by the Criterion Co. was the 1954 model 1.6 inch (40mm) aperture f/25 achromatic refracting telescope. This included three eyepieces providing 40, 80, and 111x magnification. Resembling a walking stick, it was provided on a simple alt-az mount and tripod standing about 5 feet tall and sold for $26.95. A few months after the 1.6-inch telescope became available, Criterion announced the first Dynascope, a four-inch (4″) Newtonian reflecting telescope that sold with three eyepieces in 1954 for $44.95 plus shipping. As telescope mounts and accessories improved, costs escalated accordingly. So by 1956, Criterion (among other telescope makers) was offering payment plans of up to twenty-four months.
By 1955, the first commercial 6-inch f/8 Newtonian telescope became available, made by competitor Edmund Salvage Co. This undoubtedly put pressure on Criterion to respond. Criterion may have already had their answer in the works, for in the December 1956 issue of Sky and Telescope, they announced the new series of Newtonian telescopes. This would initially include the Dynascope 6-inch with either a German mount with a wooden tripod or a deluxe German mount with a massive steel pier, and the line would grow to include models with apertures as large as 16 inches. The deluxe 6-inch Newtonian telescope, with a massive pier mount that resembled the flared bell of a trumpet, cost $475. That is $5,437 in today’s dollars.
The model on display here is the standard 6″ Dynascope from 1959.
Several versions of the Dynascope 6 telescope were produced, but the real value series RV-6, which would come to dominate its class, would not appear until January 1959 when Criterion’s two-page spread in Sky and Telescope revealed it.
Dynascope 6” f/8
The Criterion Co. was established at 331 Church Street, Hartford 3, Connecticut, by Mr. John Krewalk, Sr. In time, it became the Criterion Manufacturing Company, Inc. His son John J. Krewalk (b. 1950) would, in time, come to work for the company too.
The first telescope offered by the Criterion Co. was the 1954 model 1.6 inch (40mm) aperture f/25 achromatic refracting telescope. This included three eyepieces providing 40, 80, and 111x magnification. Resembling a walking stick, it was provided on a simple alt-az mount and tripod standing about 5 feet tall and sold for $26.95. A few months after the 1.6-inch telescope became available, Criterion announced the first Dynascope, a four-inch (4″) Newtonian reflecting telescope that sold with three eyepieces in 1954 for $44.95 plus shipping. As telescope mounts and accessories improved, costs escalated accordingly. So by 1956, Criterion (among other telescope makers) was offering payment plans of up to twenty-four months.
By 1955, the first commercial 6-inch f/8 Newtonian telescope became available, made by competitor Edmund Salvage Co. This undoubtedly put pressure on Criterion to respond. Criterion may have already had their answer in the works, for in the December 1956 issue of Sky and Telescope, they announced the new series of Newtonian telescopes. This would initially include the Dynascope 6-inch with either a German mount with a wooden tripod or a deluxe German mount with a massive steel pier, and the line would grow to include models with apertures as large as 16 inches. The deluxe 6-inch Newtonian telescope, with a massive pier mount that resembled the flared bell of a trumpet, cost $475. That is $5,437 in today’s dollars.
The model on display here is the standard 6″ Dynascope from 1959.
Several versions of the Dynascope 6 telescope were produced, but the real value series RV-6, which would come to dominate its class, would not appear until January 1959 when Criterion’s two-page spread in Sky and Telescope revealed it.
Astroscan 2001
When Edmund Scientific introduced the telescope in 1976, they called it The Edmund Wide-Field Telescope with a Part Number 2001. Edmund had a public contest, which ran until November 15, 1976, to come up with a name. The winning name was Astroscan 2001.
The Astroscan continued to be available after Edmund Scientific was acquired by Science Kit and Boreal Laboratories in 2001, with the telescope for sale on the Edmund Scientific website. Production and sales of the telescope ceased in 2013 when the mold for the plastic body broke.
Coulter CT-100
The World’s Most Compact and Versatile 4 ¼” Telescope System.
While Coulter’s advertisement slogan may be stretching it a bit, this tiny scope is certainly unique.
Early versions of the travel scope made in 1978 had a short focal ratio of f/3.5, which was changed to f/4 in 1979. Coulter even showed an f/8 version in their advertisements, though it’s not clear that the f/8’s were ever actually sold.
The one in our museum is an early f/3.5 models and from the first batch made. It did not even include the manual but a note from the factory that a manual would be shipped once they had it finished.
Coulter CT-100
The World’s Most Compact and Versatile 4 ¼” Telescope System.
While Coulter’s advertisement slogan may be stretching it a bit, this tiny scope is certainly unique.
Early versions of the travel scope made in 1978 had a short focal ratio of f/3.5, which was changed to f/4 in 1979. Coulter even showed an f/8 version in their advertisements, though it’s not clear that the f/8’s were ever actually sold.
The one in our museum is an early f/3.5 models and from the first batch made. It did not even include the manual but a note from the factory that a manual would be shipped once they had it finished.
Gilbert 63mm Reflector
A popular entry-level telescope from the mid-20th century, the Gilbert 63mm reflector introduced many amateur astronomers to the wonders of the night sky. With its achromatic lens and simple altazimuth or equatorial mounts, it provided crisp views of the Moon, planets, and bright star clusters. Affordable and accessible, the Gilbert telescopes remain a nostalgic symbol of backyard astronomy for generations.
The A.C. Gilbert Company, founded in 1909 by Alfred Carlton Gilbert, was one of the most innovative and influential toy companies of the 20th century. Headquartered in New Haven, Connecticut, the company initially specialized in manufacturing magic kits. However, it gained national fame with the release of the Erector Set in 1913, a construction toy that became an icon of American childhood.
Alfred Gilbert, a former Olympian and Yale graduate, believed in the power of toys to educate and inspire creativity. His Erector Set, featuring steel girders, nuts, bolts, and motors, was revolutionary because it allowed children to build working models of structures and machines. This hands-on approach to learning and play laid the groundwork for STEM-focused toys that followed.
Throughout the 1920s and 1930s, the A.C. Gilbert Company expanded its offerings to include chemistry sets, microscopes, and other scientific kits. These toys encouraged scientific exploration and positioned the company as a pioneer in educational toys. Gilbert’s products often targeted boys, reflecting the gender norms of the time, and the company branded itself as a producer of tools to build future engineers and scientists.
The 1950s and 1960s saw increased competition from other toy manufacturers, as well as a decline in the popularity of Gilbert’s traditional toys. Efforts to diversify into slot cars and plastic models did not replicate the success of earlier products. After Alfred Gilbert’s death in 1961, the company struggled financially and was eventually sold in 1967. By 1969, the A.C. Gilbert Company had ceased operations.
Though the company no longer exists, its influence endures. The Erector Set remains a beloved classic, and Gilbert’s commitment to blending education and play is evident in many modern toys.
Celestron
8”
The Celestron 8″ models on display here are in the back the classic orange tube C8 built in the 70s, in the middle the black C8 that first appeared in 1984, and in the front, the most recent Nexstar 8 series announced in 2000.
Celestron 8”
Celestron is a telescope manufacturing company whose name remains synonymous among the astronomical community with compact and versatile Schmidt-Cassegrain telescopes (SCTs). A Celestron Schmidt-Cassegrain telescope (SCT) was often the first astronomical instrument that a budding astronomer experienced at their High School or college, and these are still commonly found in use at government and industrial research applications as well as in a neighbor’s backyard. Celestron’s U.S.A.-made and imported products earned the well-deserved reputation of providing affordable value. The good reputation of Celestron was gained through their more than forty years of experience and success in innovative product design, most notably of their Schmidt-Cassegrain telescopes, by new innovations and continual product improvement, and their customer service. One can not underestimate the impact those pioneers at Celestron made in changing the marketplace for amateur astronomy. Celestron instruments made it possible for many amateurs to become enthralled by the hobby, and many of the now-famous names in astrophotography (and many others unpublished) were able to capture amazing images and earn recognition for their accomplishments and discoveries.
Celestron 8”
Celestron is a telescope manufacturing company whose name remains synonymous among the astronomical community with compact and versatile Schmidt-Cassegrain telescopes (SCTs). A Celestron Schmidt-Cassegrain telescope (SCT) was often the first astronomical instrument that a budding astronomer experienced at their High School or college, and these are still commonly found in use at government and industrial research applications as well as in a neighbor’s backyard. Celestron’s U.S.A.-made and imported products earned the well-deserved reputation of providing affordable value. The good reputation of Celestron was gained through their more than forty years of experience and success in innovative product design, most notably of their Schmidt-Cassegrain telescopes, by new innovations and continual product improvement, and their customer service. One can not underestimate the impact those pioneers at Celestron made in changing the marketplace for amateur astronomy. Celestron instruments made it possible for many amateurs to become enthralled by the hobby, and many of the now-famous names in astrophotography (and many others unpublished) were able to capture amazing images and earn recognition for their accomplishments and discoveries.
Celestron C90
The Celestron C90, introduced in 1978, is one of the most compact and portable telescopes. As a Maksutov-Cassegrain telescope, the C90 offered a departure from the traditional Newtonian and Schmidt-Cassegrain designs prevalent at the time.
Celestron, founded in 1960 by Tom Johnson, was already a leader in the telescope market with its revolutionary Schmidt-Cassegrain designs. By the mid-1970s, the company recognized a growing demand for smaller, more affordable, and multifunctional telescopes. The result was the C90—a compact Maksutov-Cassegrain telescope that balanced good optics with an accessible price point. The design quickly gained popularity not only among amateur astronomers but also among photographers, birdwatchers, and even military users due to its rugged construction and fine optics.
The C90 employs the Maksutov-Cassegrain optical system, which features a full-aperture meniscus corrector lens paired with spherical primary and secondary mirrors. This design minimizes optical aberrations, such as coma and spherical aberration. The C90 has a 90mm aperture and a 1000 mm focal length.
Over the years, the C90 underwent several updates, including improvements in optical coatings and mechanical designs. The most recent models feature enhanced multi-coatings for improved light transmission and sharper images. Despite these updates, the fundamental design of the C90 has remained true to its original concept, a testament to the brilliance of its initial engineering.
Celestron C5+
The Celestron 5” SCT was introduced by Celestron in 1971, just about a year after Celestron started their 8-inch SCT line with the C8. It was an orange tube, twin-arm SCT, and looked just like a scaled-down portable model of its larger sibling. The picture below shows a C5 from 1979.
In 1992, Celestron revived the 5-inch SCT and introduced the C5+. The C5+ came on a single-arm “fork” mount and was powered by a 9-volt battery. The scope was sold until 1999, when Celestron introduced the G5 and the Nexstar5.
Celestron C5+
The Celestron 5” SCT was introduced by Celestron in 1971, just about a year after Celestron started their 8-inch SCT line with the C8. It was an orange tube, twin-arm SCT, and looked just like a scaled-down portable model of its larger sibling. The picture below shows a C5 from 1979.
In 1992, Celestron revived the 5-inch SCT and introduced the C5+. The C5+ came on a single-arm “fork” mount and was powered by a 9-volt battery. The scope was sold until 1999, when Celestron introduced the G5 and the Nexstar5.
Astro-Physics 800 Mount
Dynascope Mount
Eyepiece Collection
Tele Vue
Tele Vue’s first generation Nagler (right) and Widefield (left) eyepieces. In 2005, Astronomy ran an article titled The Eyepiece that Changed Observing. In it Michael E. Bakich stated:
“On July 3, 1979, Al Nagler completed and dated the original technical drawing for the first of a series of eyepieces to carry his name. In November of that year, he applied for a patent, which was subsequently granted. The 13mm Nagler eyepiece went into production in 1980. Two additional first-generation Nagler eyepieces followed: the 9mm and the 4.8mm. These eyepieces made quite a stir when they were introduced. As well as being the highest-priced eyepiece for amateurs, the 13mm Nagler eyepiece was the first with a dual barrel, both 1-1⁄4″ and 2″, with an 82° apparent field of view to combine an expanded field of view and sharp images in the center and at the edge, and with eye relief longer than its focal length.”
Tele Vue produced this eyepiece until 2001, when it was replaced by the 13mm Type 6 Nagler with the same 82˚ field of view, weighing one-quarter as much and boasting higher-quality optical elements.
In all, the original Nagler eyepiece series, also called type 1, included focal lengths of 4.8mm, 7mm, 9mm, 11mm, and the 13mm that started it all.
In 1982, Al Nagler finalized the design for their Wide Field series. This new six-element eyepiece design provides a 65-degree apparent field of view. They were introduced in 1983 and patented in 1985. Initially offered in focal lengths of 19 and 24 mm with 1.25-inch barrels and 32 and 40 mm with 2-inch diameter barrels. In 1984, TeleVue added a 15mm Wide Field eyepiece. Astronomy Magazine reviewed these eyepieces and called them the sharpest eyepieces they had ever viewed through. The Wide Field design appealed to observers due to their improved correction over more traditional wide-angle designs of that time.
The 40mm Wide Field was about the most massive eyepiece available to the amateur, and it provided a breathtaking view that area approached the TeleVue 55mm Plossl by showing 90 percent (by diameter) of the 55mm Plossl field of view at a higher magnification.
An early accolade for the 40mm was that Michael Rudenko discovered Comet Levy-Rudenko in 1984 using his 40mm Wide Field while David Levy chose the 13mm Nagler for critical studies of the comet he co-discovered.
Carl Zeiss Jena
Carl Zeiss, Otto Schott, and Ernst Abbe developed numerous optical instruments and were co-owners of Carl Zeiss AG, the German manufacturer best known for scientific microscopes, astronomical telescopes, planetariums, and other advanced optical systems.
Abbe received his PhD from the University of Göttingen on 23 March 1861. In 1866, he became a research director at the Zeiss Optical Works, and in 1868, he invented the apochromatic lens, a microscope lens that eliminates both primary and secondary color aberrations.
The Carl Zeiss Jena orthoscopic eyepieces were made
Carl Zeiss near his workshop in Jena. in focal lengths of 4, 6, 8, 10, 12.5, 16, 25, and 40 mm and had barrels of 0.965 inch diameter. They were produced from before 1930 to the early 90s with some changes to the overall design and coatings.
This now famous orthoscopic design originated from Zeiss. Ernst Abbe was a physicist who worked for Carl Zeiss during the late 19th and early 20th centuries and is credited with creating this design in 1880. It consists of a triplet cemented field lens and a singlet eye lens for four elements of glass.
Edmund Scientific RKE
The Edmund Scientific RKE (Rank-Kaspereit-Erfle) eyepieces are well-regarded in the amateur astronomy community for their simplicity, optical quality, and affordability. Introduced in 1979 by Edmund Scientific, these eyepieces were designed by Dr. David Rank, a physicist and optical designer, as a refinement of the earlier Kellner and Erfle designs and without the complexity and cost of more elaborate designs like Plössls or orthoscopics. Over time, the line became popular among amateur astronomers for its high contrast, sharp images, and relatively low cost.
Despite the emergence of more advanced eyepiece designs, RKE eyepieces remain in production today, making them the longest-running eyepiece series.
RKE eyepieces have three optical elements and offer an apparent field of view of about 45–50 degrees, which is narrower than most modern eyepieces. The design offers comfortable eye relief, especially in the longer focal lengths, making them suitable for users who wear glasses. The lenses are fully multi-coated to reduce glare and maximize light transmission. The line includes focal lengths of 8, 12, 15, 21, and 28 mm. Of those, all, except the 15 mm RKE, can still be purchased new from Edmund Scientific.
The 28mm RKE, in particular, is celebrated for its immersive viewing experience, often described as a “floating image” effect due to its optical properties. Known for their sharp central resolution, high contrast, and low chromatic aberration, the eyepieces are well regarded for planetary observation and lunar viewing.
Criterion
Orthoscopics and Königs
Meade Research Grade
Coulter
Kellner eyepieces of the Coulter CT-100
Meteorite Collection
Campo del Cielo Meteorite
Meteorite Collection
About the Museum
Our Deepsky Astronomy Museum is located at the Chiefland Astronomy Village. It was founded in November 2024.
The museum is managed and operate by our dedicated volunteers:
- Curator: Dr. Richard G. Hennig
- Restoration: David Froiseth
- Facilities: Lisa Eager
- Communications: Matthew Peters
- Archivist: Sarah Coates