My Zeiss AS 130/1950 telescope (1995–2010)

There are moments in life—that one opportunity—that simply cannot be resisted.

That is exactly what happened in 1995 when, thanks to good connections with Michael Gutzeit and Rudi Idler, I was able to purchase a new legendary AS 130/1950 lens from the Carl Zeiss Jena stock.

This objective was mounted in a Krüpax tube (laminated cardboard isolator )manufactured by Krüger & Sohn. A two-part aluminum adapter featuring three push-pull screws allowed for the alignment of the lens cell relative to the tube.

I was able to acquire a Vixen Saturn mount from an observer fellow in Backnang; I constructed the necessary tripod using U-profiles made from 25mm European beech plywood. To do this, I had to purchase an entire 30-square-feet sheet. This base is heavy but extremely stable, as it has to securely support a combined weight of over 70 pounds—comprising the telescope, mount, and counterweights.

I didn't run out of yellow paint when painting the telescope, and there was enough left over for more telescopes. Thus, yellow became the signature color for my homemade telescopes.

Initially, a 2-inch Vixen focuser was mounted at the rear of the tube; this was later replaced by a sturdier, custom-made focuser with a 3.5-inch clear aperture.

With a Baader 60° binoviewer as an optional accessory—gifted to me by my friend Albert Wacker—the Zeiss AS 130 was a fine astronomical instrument featuring sharp, high-contrast optics, particularly well-suited for observing the Sun, Moon, planets, and stars.

From 1995 onwards, I transported this refractor—which, together with its mount and tripod, weighed 150ponds —in a Peugeot 205 compact car to observing sites and to the ITT Star Party in Carinthia.

Thanks to its 12 inch of back focus, it just barely fit. The lens end was covered with a pillow gainst the dashboard. There was only a gap of a few centimeters between the focuser and the rear window, which was padded with a blanket. During the journey, the tube—secured inside a ski bag with a strap—rested on the tripod legs, which were positioned on the passenger seat in a reclined, angled position.

Years later, I cast a concrete pillar in our garden by the vineyard. The Zeiss stood firmly on it for solar observation, and it was quick to set up.

During the "Mars opposition of the millennium" in 2003, I seized every opportunity to invite friends and neighbors over to observe Mars through the Zeiss telescope. It was a special experience to compare the neighboring planet's surface features with maps and identify them. Solis Lacus—the "Eye" of Mars—was a spectacular sight at the time, and Valles Marineris could also be made out nearby. At the ITT, I also spotted a small, bright cloud marking the location of volcano Olympus Mons.

In 2006, I began building a Unigraph-style solar observation setup based on Harald Paleske’s design. my friend Reiner machined four conical baffles and tube sleeves for me. A suitable projection lens and an iris diaphragm were also procured.

Ultimately, this project fell through because I couldn't get a suitable, narrow-bandwidth H-alpha filter at the time. New filters were unavailable, and after three failed purchases of used filters, I gave up.

Over the years, I noticed that the image quality of the Zeiss objective had deteriorated. Perhaps this was the result of a bump sustained while carrying the long tube through the stairwell? Using his optical bench, Wolfgang Rohr confirmed the presence of astigmatism caused by a compressed spacer between the objective lenses.

He fashioned new spacer shims out of tin and, through patient and skilled manual work, succeeded in the feat of correcting my Zeiss objective back to a Strehl ratio of 0.98.

In the autumn of 2010, I sold the Zeiss AS 130 in favor of a new project: building a top-quality 16 inch telescope suitable for air travel.