[rogerg (Roger)]

Originally Posted by The_bluester

What would be the minimum width of shed people would consider (Length is another issue completely, more on that later) to mount the refractor in the middle, point it at the horizon (Which won't be visible) and allow space for set up/working on it etc. Basically, how much "Walking around" space outside the envelope the scope will occupy would you want to have in an ideal world?

The open portion of my observatory is 3m x 3m, with a PME and 12" SCT in the middle of that area. I've often given thought to adding a second telescope of similar size and have come to the conclusion I would want the space to be 3m x 5m, perhaps 3m x 6m if money and space were not an issue.

Originally Posted by The_bluester

The second question would be wall height, how low to the horizon would you consider imaging? I am hoping to have the walls high enough to block stray light from car headlights as we are on a bend in a road and headlights sweep our place from side to side all the time. I was also thinking that matte black paint on the inside would be a good idea to help cut that problem even further, at least for the top half of the walls. Ideal wall height would allow a normal door to be used under the roll off roof without bumping your head!

My walls are 2.0m high. That height is generally good. I can image quite low to the horizon on three sides (guess 10 degrees most directions - ignoring trees etc!). I have a pitched roof (hence the scope is not entirely below the 2m height of the walls). The only problem is to one side where the pitch of my roof is and obstructs the north more than the other walls do. I don't have black walls, they are the standard colourbond under-side colour. I don't have a problem with stray light or such even with lights on, having the telescope optical path fully sealed and due shield on.

My door is a good height for me (me being 1.78m tall) but taller visitors need to be warned. There's also horizontal support beams inside the enclosed half of my observatory which cross at about 1.9m height so taller visitors require warning!. Problem with making it all higher is increasing the wall height. I can think of ways to get around this now - higher enclosed half than open half with taller "skirts" coming down from the rolling roof).

Originally Posted by The_bluester

My wife also made the suggestion of a section of the shed partitioned off from the scopes and weather protected (The length issue) to allow for a couple of bunks for those long imaging sessions! (I think she just wants us to stay out there and stop bumping around the house at 3AM looking for whiskey) If I were to add a bunkhouse, is there value in cable extensions so that laptops for imaging could be put in there? I can see an obvious benefit in reduction of stray light when capturing images if laptop screens were out of the way with walls between them and lense, but does it matter?

I wouldn't be without the enclosed half of my observatory. Warm, comfortable, dust free, dew free, nicely set up, a space to spend time. Cable ducting from piers to nearest wall of observatory and then along walls to enclosed portion is essential. I used 90mm storm-water pipe under the concrete slab but even that is getting maxed out with cables now and I would've preferred two, one for power and one for data.

Originally Posted by The_bluester

Piers, I plan a concrete floor in this for cleanliness, is there real value for imaging if the pier is isolated form the shed floor? I have a 12" post hole auger on a tractor which I can sink to about 800mm to put in a footing for a pier, am I best off to carry this 12" above the ground a little (Thinking of stubbed toes here) and use the rubber isolator/expansion strips they use nowadays in concreting to prevent contact between the floor slab and pier base? Visually I can not see it making any real difference, but photographically? I would hate for us to have to spend the night making sure to sit still to keep vibrations at bay.

My pier is steel, embedded in about a cubic metre of concrete and seperated from the rest of the concrete pad by rubber expansion foam. I think having it separated from the rest of the slab does help reduce vibrations. Amount of concrete is up to you or some engineer to guestimate I guess I'd recommend concrete pier rather than steel. I did have issues with vibration from my pier but filling it with sand negates that, but may as well be concrete I think. Most vibrations I've experienced come from wind which ripples over the walls.

Originally Posted by The_bluester

This could end up more comfy than my house, but I will only get one shot at this, so any other suggestions for an ambit claim for the "Features"?

Nice sound system (consider wire ducting), consider wire ducting for ventilation fan(s) to cool down after a hot day or such (I have one in my enclosed half). I have insulated the enclosed half of mine which makes it comfortable but it holds way too much heat in summer. Definitely don't insulate your open half if you have a climate like Perth, except the roof with thin reflective insulation. Condensation inside the open half can be a problem during winter when it's closed up, so consdier options for mitigating this so you don't have it dripping on equipment (the thin insulation on the roof would probably do it). Don't foreget to plan for remote operaiton, with ducted network cables, ducting to put weather station on top of the roof, etc.

Originally Posted by The_bluester

This is also going to be a project of quite some time in the making, probably starting with piers and then a slab and finally a shed, but if I am going to move to that last stage and build a shed over it all then I need to get the dimensions right from the beginning.

These things are iterative and take time to progress. I've had mine for about 14 years now and it took a good 10 years to build it up to where it is now, comfortable and easy to use.

See more about my obs: http://rogergroom.com/astronomy-reso...y-observatory/