The first thing that struck me when I initially set up my telescope in the garden was how exposed I was. I had, over a period of several weeks, cut down the overlarge Christmas tree which occupied the prime observing site in the garden, dug up the turf and levelled it as best I could, then used ten 2ft square slabs that I had lying around to create quite a nice flat platform. But it didn't protect me from the wind or, more important, stray lights. Worse, one of the neighbours hedges had been trimmed so that an orange street light was now shining on to my chosen spot, albeit from at least a 100 yards away.
I am lucky in so far that the whole bottom of the garden, which faces roughly southeast, is bounded by vegetation and there are no lights other than the distant skyglow of Swansea, which is annoying enough. But the garden slopes down from the opposite northwest side where our house and those of our neighbours stand. Then there is the street with the usual orange lights the other side of the road with more houses. Unfortunately, as we are not overlooked at the back our neighbours tend to be a bit careless with curtains and their lights. And some have floodlights though I have never experienced these whilst out observing. But I found it difficult to avoid catching the odd light that was on in someones bedroom or kitchen. Well, not just difficult but impossible unless I stayed up until everyone had gone to bed and turned out all the lights.
So I was faced with a couple of choices. I could become a real night owl - or I could become a mobile observer packing up my scope into the car and driving to a convenient dark spot and setting up there. Neither option appealed.
I am quite prepared to stay up late but the prospect of having to wait an unknown length of time before I could do anything wasn't really sensible. As for the option of driving somewhere - well it costs time and money. Worse, I didn't fancy the prospect of arriving somewhere only to find that the clouds had closed in. Star parties and the regular observing sessions which my local society organise are a different matter as there is always something to do, even if the weather is unfavourable. And I had quite a reasonable place to observe from in my own back garden, if I could only solve the problem of the lights. There was also the matter of having to store my telescope and bits and pieces. I obviously needed an observatory.
For some time after I reached that conclusion I did nothing. An observatory of any sort would cost serious money. Could I really justify it? Was my interest sufficient to justify that amount of money? And what would my wife say?
Well, I am lucky in that I am retired and no longer encumbered by a mortgage or raising a family. But after a life-time of being careful with money I have always found it difficult to justify spending money on myself rather than my family.
I disregarded the do-it-yourself garden shed option as I haven't either the time, tools or expertise to do that sort thing. So I was left with a choice between the 2 main kinds of observatory, the fibre-glass domes or the roll-off wooden garden sheds.
At that time in the UK there were really only 2 kinds of complete domes available for the amateur observor, the 2.2m or 2.7m full-height domes from Pulsar Observatories or the 2.4m Sky Shed Pod from Altair Astro - see here for a review of these. The only roll-off wooden sheds were from Alexander Observatories which offer a wide variety of sizes. Recently at least 2 other companies have started offering these kinds of sheds. Of these I used to recommend Ian King Imaging, but in the light of the problems that the Swansea Astronomical Society experienced I can no longer do so, even though they say they have changed how they build. As for Alexander, I believe they are no longer in existence. Home farm observatories have built some interesting observatories so may be worth considering.
But for me, even though the roll-off's are quite a bit cheaper and despite having a large back garden, I didn't really have the right kind of space to accommodate one. If put in my chosen/best spot the roof supports would intrude into the 'nicer' part of my garden. And once the roof was rolled off I would still face the problem of stray lights and exposure to the elements, though these would be reduced somewhat because of the walls. With regard to the Skyshed again, although it was not as expensive as the full height dome of Pulsar, the stray light/exposure problem still remained. So I went ahead and eventually ended up with
Ian King roll-off observatory
Pulsar 2.2m full height dome