Last week I spent some time at the S9 building of Ghent University where the local Public Observatory Armand Pien found a temporary shelter during the renovation works on their observatory (located in another university building). The S9 building is also the home for a group of ATM, and the heart of the School Telescope project in Belgium and the Netherlands.
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| Jean-Pierre Grootaerd, one of the volunteers of the Amateur Telescope Making group showing a finished mirror. In the back is the vacuum chamber used to apply coatings to the mirrors. |
Assisted by volunteers, students or schools can build their own Dobson telescope. Mirrors are usually somewhere in the 8 to 10 inch range, but larger instruments have materialized too. I was there on assignment for a Belgian newspaper. The article, pictures and video can (partly) be seen on the newspaper online site.
It's great to see over 60 scopes have been built in only three years time. The mirrors are ground and polished from fused layers of plate glass. Simple dobson mounts are used, but tracking platforms are now being offered as an add-on too.
As a matter of fact, with a good tracking platform, webcam astrophotography surely is within reach of dobsonian telescopes. Early March, under mediocre seeing, I could make a few webcam images of Jupiter and a nicely sharp image of the moon using a Skywatcher Flextube 12 inch GOTO scope. For the mount I used a 1.8x TMB barlow, for Jupiter a 3x Televue barlow with RGB and IR filters. The dual-axis tracking system worked like a charm for this kind of photography. Visually, Jupiter easily remains in the field of view for nearly an hour at high magnification. A dream for visual observation of the planets (and equally for deep-sky objects).
