admittedly, I can hardly resist the charm of old long tube refractors.
Recently I added to my small collection of vintage telescopes a Kenko 'NES-90' 90/1300 achromat, complete with all the documentation and accessories that were originally part of the set. According to what I think is a quality certificate, this telescope was produced in 1990.
The Kenko 90/1300 is well regarded amongst the italian astro amateurs community, although all those I have read about are later models featuring the light blue color for both the OTA and NES mount. My sample has the previous black-and-white color for the OTA while the NES mount is all black.
A sensible difference with later models lies in the objective cell that in my sample can be collimated with three couples of push-pull screws.
Visually the telescope shows a nice star test, with diffraction ring patterns quite similar between extra and intra focal position. In intra focal the first diffraction ring looks to me a bit more diffuse on its border than in extra, with the adjacent, internal first black ring a teeny bit darker than its extra counterpart.
In focus the stars look like textbook Airy disks surrounded by a faint first diffraction ring, a quite 'classical' view.
The celestial views are very 'calm' as is to be expected by the relaxed f14,4 focal ratio, no chromatic aberration is apparent in the center of the field of view.
Now for some photographs of the newcomer, mount and accessories.
Would love to hear from others CNers experiences with this old school achromat.
Clear Skies from Italy!