Looking for the best book to help you learn the fine points of building everything from light-weight giant Dobsonians to tiny travel scopes, and to help keep you from making expensive mistakes? Look no farther. TMD has been constantly updated so  your next project will be a success - and not an old-fashioned dinosaur! Order your copy today!

Can you imagine an 8" f/6 that only weighs 25 pounds and folds up into a 12x12x13" box? Here are the photos.

Travel Scopes

Tom Clark pioneered these fold-up designs where all the parts nest inside of each other for easy transportation and storage. The mounts are rock solid, while being easy and fast to assemble.

This 18" f/5 was built for a trip to the southern hemisphere in 1994. Total weight is 97 pounds. We observed with it from Lake Titacaca in Bolivia, at an altitude of 12,800 feet. What views!

Nesting Design for Portability

Large Telescopes


Tom built The Yard Scope in 1992 and it was one of the largest amateur instruments in the world at that time. The 36" f/5 mirror is one yard in aperture - thus the name. The 540 pound monster is one of the most famous amateur telescopes ever built. The 360 pound 36" f4.5 Yard Scope II was built in 1998 and used at the author's home in Chiefland, FL until replaced with a larger instrument in 2003.

Order your copy of The Modern Dobsonian today, and learn from the author's 25 years of experience in building telescopes. Mail your check to: 


Tom Clark

5450 NW 52 Ct.

Chiefland, FL  32626


Only $12.95 + $3.50 shipping ($16.45) to your US address.

Medium Size Telescopes


The most popular amateur scopes are the 12-20" sizes.

    Under the name Tectron Telescopes, Tom Clark has built nearly 200 telescopes for customers around the world. On the left is an early 25" f/5 that weighed 250 pounds. On the right is the 24" f/4.5 that replaced it when we started building ultra-lights. This 24" f4.5 only weighs 160 pounds, yet is ultra-stable. It folds up into a 30x30x24" box for traveling.

Here is the author with a 32" f/4.5. It features a removable mirror box to make set up very easy. This scope could be set up with two guys in less than 10 minutes. Any scope that is easy to transport and set up is one that will be used a lot.

Above is Tom's 24' home-made dome that is on the edge of the club observing field in Chiefland, FL. The scope is a 42" f/4. It is 14' long, weighs 1600 pounds, and has a go-to drive to make observing from inside the dome a pleasure. Watch the observatory and telescope construction in this side show.

Tom lives in the Chiefland Astronomy Village in north Florida. Serious astronomers are welcome to join us for some of the finest observing in the east. We have members from 18 states who regularly come to Chiefland for astronomy vacations. Chiefland.htmlChiefland.htmlshapeimage_5_link_0

Compare the size of the non-folding 6" f/8 with the folded up 8" f/6, 12" f/6, and 24" f/4.5. The 24" takes less floor space than the 6" does. The cart the scope is sitting  on allows the author to easily load  the scope into his van by himself for trips to star parties.

This 10" f/5.6 weighs 56 pounds and isn't a lot bigger than the 8", yet provides excellent views.

TMD shows the construction of my 18x18x20"

12" f/6 that only weighs 54 pounds. (photo below)

Tom Clark and Vic Menard worked together building these foam and fiberglass 16" and 20" fork-mounted Newtonians in 1986. They were featured in Sky and Telescope in 1987.

Tom's workshop in 1992 with six 15" f/5s under construction. Tom retired from Tectron Telescopes in 1999 and no longer takes orders for telescopes.

First published in 1992   

Just Out!  Now in the Fifth Edition - revised in 2010 

8.5" x 11"  92 pages

Only $12.95 + $3.50 shipping to your US address.

The Yard Scope 36" f/5

The Yard Scope II  36" f/4.5

24" f4.5

8" f/6

6" f/8

Starry Starry Nights   Tom's newest book shares nearly 30 years of his adventures of building and observing with some of the largest amateur telescopes in the world, and living the astronomer's dream.


Tectron Telescopes  Tom's latest telescope making projects and the occasional scope for sale.


Astro Memories     Sharing 30 years of being a telescope maker and amateur astronomer in photos.


The Chiefland Observers  If you would you like to visit one of the finest observing sites in the country, here is our group's web page to get you started. This is your invitation to look through a 42". Email ahead please!


Talk to the Astronomy Gods - An article about observing with very large telescopes.


It's the Seeing, Mate    - An article on large scope observing at the Winter Star Party


The Chiefland Experiment  Part I   Learn about how the Chiefland Astronomy Village was started.


The Chiefland Experiment Part II    Read about living at and running an astronomy village.


Collimation     Tom's article on collimation appeared in issue #17 of Amateur Astronomy Magazine and covers using Tectron collimation tools. They were designed by Tom in 1986 and produced until 2007 when Tom retired. For over 20 years they were the best collimation tools available.


Observing Etiquette      If you are new to astronomy, here is an article to get you up to speed on how to fit in  at observing events. This article first appeared in  Sky and Telescope in 9/93, and it ran in Amateur Astronomy Magazine in #18, summer 1998.


The New Mexico Astronomy Village Time to fulfill your wildest observing dreams…

Above and below are Tom's personal scopes. The 8" and 12" fold up so small that they can be carried anywhere. The 24" is used in our yard at Chiefland, and taken to star parties around the country.

12" f/6

24" f4.5 at the Winter Star Party

Related Astronomy Articles and Presentations

16" f/4.5 and 24" f4.5 set up at 8400' in Colorado