105mm f6 Traveler EDFS 4.1 aperture (105EDFS)

The 105mm f6 Traveler is not available to purchase and we do not have any plans to produce additional scopes with these exact specifications. This information is presented for present owners and those who are curious about its history.

105mm f6 Traveler, 400GTO German Equatorial Mount, Adjustable Aluminum Tripod, one 9 lb. Counterweight and other accessories.

More pictures of 105EDFS and other accessories

Imagine an Apo refractor with a 105mm (4.1") aperture, focal ratio of f6, in a tube assembly that has an overall length of 19"! The 105 Traveler is the culmination of years of optical research by Roland Christen of Astro-Physics aimed at developing a very fast and portable telescope that will allow you to enjoy sharp, high-contrast images wherever you go.

The Traveler is an awesome performer both at night and during the day due to the superb figure of the lens and extremely efficient design of the optical system. Based on light gathering area alone, the Traveler has 36% more light grasp than a 3.5" Maksutov and 10% more light grasp than a 100mm refractor.

During the daytime, delicate detail and vivid colors of flowers and wildlife are a true joy to observe. When viewing at night, the high light transmission of the extremely pure optical glass becomes immediately apparent. With a 2" widefield eyepiece, we have seen the entire Veil Nebula, including the very faint inner region, all in one eyepiece field of view. The North American Nebula region is so bright and clear, it looks like a deep-sky astrophoto. Pop in a high-power eyepiece, and you will be rewarded with truly stunning views of the Moon and planets. Jupiter will amaze you with sharp resolution of the bands, festoons, white ovals and the Great Red Spot. This scope shows detail on Saturn and Mars that rival views in much larger instruments.

The Traveler is a fabulous astrograph for film or CCD. With a Pentax 6 x 7cm camera coupled with our 2.7" field flattener specifically designed for this instrument (67PF462), you can capture 5.6 x 6.6 degrees of stunning star fields, clusters and nebulas at f6! This same field flattener can be coupled to your favorite SBIG or FLI CCD camera (with or with out the color filter wheel) by means of a simple adapter. If a faster focal ratio in a 35mm format is desired, use our Telecompressor (27TVPH) for f4.5, or our 2x Barlow (BARCON) for f12 exposures. Be sure to check out the exquisite images in our gallery that have been taken with this telescope.

Whether traveling to exotic eclipse locations, your favorite camping spot, bird watching expeditions or just into your backyard, this little gem will provide you with hours of observing pleasure.

Color correction Less than 0.01% focus variation from 405nm to 706nm (r to h wavelengths). Color correction curves.

Clear aperture

105mm (4.1")

Focal length

610mm (24") (actually f5.8)


1.1 arc seconds


Multi-layer, overall transmission greater than 97% in peak visual wavelengths

Magnification range

12x to 400x

Tube assembly

Black finish, 19" aluminum tube, fully baffled, permanently aligned cell construction; flat black interior, engraved focuser

Focuser type

2.7" I.D. Astro-Physics rack & pinion focuser, 4.15" travel; 2" and 1.25" adapters; 2.5" extension

Telescope length

48cm (19") w/ dewcap fully retracted

Weight with dewcap

9 lbs. (4 kg)

Carrying-case type

Custom padded soft case

Case outside dimensions

21" x 10.8" x 7" (53cm x 27cm x 18cm)

Weight of case

3.5 lbs. (1.6 kg)

Photographic Field
35mm Photographic field at prime-focus 2.3 x 3.2 degrees @ f5.8
35mm Photographic field with telecompressor

2.9 x 4.1 degrees @ f4.5

35mm Photographic field with 2x Barlow

1.1 x 1.6 degrees @ f11.6

6x7cm Photographic field at prime focus

5.6 x 6.5 degrees @ f5.8 (vignetted)

Reviews and Related Articles

Dyer, Alan. "Astro-Physics Big & Small, Astronomy, September 1993, pp.62-67.


We have prepared some pertinent support documents relating to this scope and many of our other products on our Technical Support page. Please check there first to find the information that you need.

Upgrades and Spare Parts

Check out our website to find accessories, replacement parts or learn about possible upgrades for your scope.

Copyright 2004 - 2019 Astro-Physics Inc. All rights reserved.
Last modified: March 11, 2019

Astro-Physics, Inc.
11250 Forest Hills Road, Rockford, IL  61115, U.S.A.
Phone: 815-282-1513   Fax: 815-282-9847