20.1.13

Fullerscopes Eyepieces

*
Clive, my contact in the UK, has kindly provided some images of his extensive collection of Fullerscopes and Telescope House eyepieces. Telescope House replaced Fullerscopes as their company name. The majority of those shown below were sourced in Japan by Fullerscopes. (or later by Telescope House)



I can remember mulling over the purchase of a Fullerscopes Kellner in my impoverished youth. Staring at the Fullerscopes catalogue filled many hours over the years.


The first two are Kellners. These are a Ramsden design with an achromatic eye lens.
'

This is an Erfle. A more complex design which promised a wider field than the simpler designs. Though usually at higher cost. They employed two achromats separated by a simple lens.


A range of Telescope House Orthoscopics.
For many years Orthoscopics were touted as the eyepiece of choice.


Later Telescope House Orthoscopics.


Three Fullerscopes Orthoscopics.
These employed a triplet field lens with a simple eye lens.
They promised greater eye relief over the simpler types. 


A pair of Fullerscopes Ramsden eyepieces.
These utilised a simple (non-achromatic) lens for both eye and field lens.
A very old design, with limited eye-relief,  but still useful with longer focal length telescopes.
Best avoided with short focal length or "fast" optics.


This is an in-house produced Fullerscopes Barlow in a brass housing. The Barlow lens is a popular device for increasing magnification from existing eyepieces. The majority of Barlows offered a doubling of magnification. They did so by extending the original focal length of the telescope using a negative lens. Though without doubling the tube length required. The Barlow is slid into the telescope's focusing mount. The eyepiece is then inserted into the open end of the Barlow housing. Some variation of power is possible by sliding the Barlow in or out of the focuser. 



Those marked NS are from NIHON SEIKO, Kenkyusho Ltd of Nozawa, Setaegaya-ku,  Tokyo, Japan
There are others marked Circle T. Distributed by KOKUSAI KOHKI But the manufacturer was Tansutzu Tanny/Tannoy, Tokyo, Japan.

My thanks go, yet again, to Clive for his kindness in taking and providing these images and for permission to share them on my blog. Thanks also for the explanation of the markings.

Here is an excellent webpage on many more kinds of eyepieces: Telescope eyepiece 2



Click on any image for an enlargement.

*

4.1.13

Baaring Rytmiske Efterskole observatory

*

I spotted the old observatory dome, through the bare winter trees, on one of my regular cycle rides yesterday. The Rytmiske Skole is situated high up in the hillside village of Baaring. This village lies not far from the motorway between the villages of Brenderup and Nørre Åby.

From the steep, narrow, school drive one branches off to the left away from the main entrance. After a turn to the right the dome can then be seen on its raised platform on galvanised stilts. The trees have obviously grown considerably over the years and now block the view of most of the night sky from the dome.

The walls of the dome are in much worse state than my last visit of several years ago. Despite the raised platform, the trees block much of the view from the dome. The pictures tell much of the story. From memory, the telescope was an 8" skeleton Newtonian on quite a sturdy mounting of probably Danish manufacture. Probably dating from the 1960s. It was already heavily rusted and completely unusable on my last visit.

The whole project was probably due to an enthusiastic, local, amateur astronomer. Perhaps a teacher at the school? The steelwork for the raised platform and access stairs must have added considerably to the cost of the project. It is a great shame that the considerable investment was not maintained and kept in useful working order. Presumably the enthusiast retired. Leaving nobody to supervise the use of the observatory. The dome walls show further signs of deliberate damage. While a crude board has been fixed over the previously and permanently open doorway.  On my last visit I had no difficulty climbing the stairs and examining the telescope through the open door without any interest being shown by pupils or staff.

The steep, but sturdy, stairs offer reasonable access and improved the sky coverage from the raised dome. The stairs face the school buildings which helps to reduces the risk of unauthorised access. The observatory seems to have suffered more from lingering neglect rather than deliberate damage over the long decades since its erection.

Note the tall concrete pillar to support the telescope mounting. This is isolated from the observatory floor to avoid vibrating the telescope. The steelwork is well triangulated with tensioning rods to reduce sway under wind loads and any movement by observers.

I am unsure of the material of the dome but must be of metal to have survived so long. The amateur's popular choice of hardboard would have disintegrated decades ago- The raised position is hardly conducive to regular dome painting. Though the dome does show clears signs of having been painted in the past. The wooden boards forming the vertically planked walls are showing clear signs of rotting at the bottom.

Without a local and knowledgeable adult to repair, maintain and supervise it is very difficult to imagine the observatory ever being put to good use again. The growing trees increasingly limit the view of sky on one side. With the school blocking the view on the other.

Ideally the existing telescope and mounting would be removed and replaced with a much more modern instrument. The dome walls and probably the floor need replacement further adding to the high cost of reinstatement. There may be very little interest in doing more than tolerating its existence until it becomes dangerous and is demolished. A rather negative view but probably realistic.

I wonder if they would be willing to sell the dome before it falls to pieces? The steelwork platform would give me a much better view over my own trees or over the roof of my house.. At about 2 metres diameter (at a wild guess) the dome would house my 6" F:8 refractor rather nicely. Though I hesitate to think what it would cost to lift it down onto a lorry and have it delivered the 20-odd miles to my home! Then I'd need a crane to lift the dome onto whatever I made in the way of observatory walls.

It would be far easier (though arguably more expensive) to buy a new fibreglass dome. Which would be so much lighter that it could (probably) be quite easily raised by a only a few people. I can't imagine what it costs to hire a crane!

Later examination, on another visit, suggests that the dome is in fact fibreglass (GRP) as the surface clearly shows fine glass mat strands. Not true! It is plywood with an overcoat.

Sadly, this long unused dome and rusting telescope have gone, along with its supporting steel work.

Click on any image for an enlargement.

*