there are a lot of considerations when using an observatory. First, the building has to be high enough to hold your equipment and for the observer to be comfortable. A refractor can be pretty tall. Most of us have obstructions near the horizon such as houses, trees etc. so that limits how close to the horizon you can view. Also, the closer to the horizon the more atmosphere you have to look through which degrades the image. The best viewing area us usually over head and up to 45 degrees from the zenith in any direction. The higher walls also serve to block any wind from affecting your telescope. They also help block light pollution from street lights, neighbors yard lights and even light glow from nearby urban areas. Down here in south Florida they also make it harder for the mosquitos to find you! As to cutting down on the amount of sky you could observe, you can only look at one spot at a time! If you think about it, sooner or later the whole sky comes by for you to view! In your hemisphere of course. You should set up your viewing schedule before you start for the night. Use a program like the sky to make your selections. Also, you can measure the angle viewable from your observatory and then set the viewing limits on your AutoStar. Then you use the best objects tour and your scope computer will pick and choose the best of the best within your available slice of sky! That way you get to see a lot of new objects you never thought of viewing before. A newbie to the hobby might feel confined because he might have a tendency to jump around looking for things he has heard about or looked at before. But in truth, there is always something to see right in front of your objective lens no matter where it is pointed! Many of the great discoveries were made by large telescopes that had elevation only and had to wait for their prey to come to them, like a spider in its web. Rethink your observatory concept and I think you will agree that 5 or 6' walls help more than they hinder. Good Luck! George D