Observatory Side Walls

[teifistar]

Hi,

Firstly I am very much a newbie to astronomy but have been reading and researching a lot over the last few months. I eventually bought a Skywatcher 250pds and NEQ6 Pro mount. I have room for and observatory so over the last few weeks I have been building the floor and pier.

The floor and pier are now complete and today I mounted the scope to test how high the side walls should be.

The pier height is 31ins and floor size 10ft x 10ft. The roof will be a pitched roof roll off.

Before I start to plan the remainder of the observatory I wanted to ask what height the side walls should be as I know observing below a certain elevation is not good.

After testing today I could still not reach a conclusion so what do you think? I am edging towards choosing 6ft walls. Will I miss a lot of the sky with side walls this high?

Thanks,

Peter

[r3i]

Whilst there's plenty of good, standard advice on how long/wide to make an observatory, when it comes to the height it very much depends I think on your local circumstances. 

I went for 1.8m high walls with a drop down flap on the southern side.  This has been fine for me as the height of the walls provide some protection from the wind (we get a lot of that round here). This does cut off parts of the horizon but then again I'd probably not do much imaging there anyway, due to the lack of clarity in the atmosphere.  There's always plenty of stuff to image higher in the sky so I don't lose sleep over it.

Others have preferred to make lower walls and build the upper part of the wall into the rolling roof.  Olly and Gina have done this on their observatories.

As you already have started doing, the best thing to do would be to stand where your scope will be and try to get a feel on what you would and wouldn't see with a particular wall height.  Perhaps you can rig up a temporary screen to simulate a wall?

[mikeDnight]

Hi Peter.

For my own observatory I chose to build the walls out of 3/4" marine ply on a 3" by 2" frame, externally clad in white plastic tongue and groove which reflects heat, with the inside clad in black rubber matting to absorb stray light and aid in dark adaption, and is maintenance free.

The walls are 6' 6" high for three reasons. 1). I've found from my site there is little point in trying to observe below 30° as the seeing is not good enough. 2). The high walls help to block out unwanted light and act as a wind break. 3). I tend to use refractors, so the pier is tall, giving me a good all round view.

I think even if I used a Newtonian I'd still have walls around the 6 foot mark to protect from wind and light. To me comfort would be more important than being able to view the horizon.

Mike :-)

[teifistar]

Thanks for the replies, I am pretty sure I can see 70% of what is available with 6ft side walls. Mike can you point me to Gina's rolling roof with extended sidewalls, thanks.

Peter

[laser_jock99]

The other possibilty is park the scope 'weights up' then remove them before closing the lid.

In use the scope can then actually look 'over the top'.

This is not a standard configuration- just something I arrived at by accident as the pier & walls was built before I decided to put a 12" scope on it!

[r3i]

Thanks for the replies, I am pretty sure I can see 70% of what is available with 6ft side walls. Mike can you point me to Gina's rolling roof with extended sidewalls, thanks.

Peter

There were several threads but here are a couple:

http://stargazerslounge.com/topic/103600-ginas-observatory

http://stargazerslounge.com/topic/116563-ginas-observatory-the-build

[michael8554]

I agree with all the comments that observing down to the horizon is not optimum.

But you can save yourself a shedload (geddit) of nightime observing time by being able to focus on a distant object during the day.

To find focus on a new camera setup, align the finderscope, centralise your Crayford travel, re-centre your guidescope to the main scope, to name but a few.

Maybe a small removable panel?

Michael

[Scorpius]

This is a great thread! Following it with much interest since this is a decision I'll need to make soon - at least hope it will be soon once I get the pier installed while remembering to account for finished floor elevation...

[laser_jock99]

I agree with all the comments that observing down to the horizon is not optimum.

Michael

That depends on how good your horizons are.

[Scorpius]

That depends on how good your horizons are.

Mine aren't very good - nice remote spot in a 5 acre field but forest around the perimeter which are higher in the east, south & west due to the lay of the land and most convenient location for the observatory. Not sure exactly how many degrees to the tree tops but pretty sure it's less than 30. Is there anything below 30 worth trying to image through all that atmosphere or shouldn't you wait til it's 30 or more before doing photography anyway? I realize an observatory isn't just for imaging but even for visual, it seems like a 30 degree baseline would be acceptable.

I don't know - which is why I'm asking - because the only way I could lower my E/S/W horizons would be to raise the observatory - not yet built btw - or cut down a lot of trees!

[teifistar]

I have fixed the height of the side walls at 6ft. This will give me some shelter, I do not have light pollution to worry about and I can walk around comfortably when the roof is closed. I did consider that in operation if I find the walls to high then I will extend the pier height, another 10/12 inches will make a significant difference. I have prefabricated all the sides and I am about to assemble them on the flooring, will post some pics later on.

Peter.

[Tim99]

Thanks for the info/advice everyone.  I am planning a springtime build.  Getting ducks in a row.

[michaelmorris]

Ideally, you want the side walls high enough to cut out stray light and reduce wind hitting the scope tube and low enough that you can get pretty much right down to the horizon.

Of course, for most of us this is not acheiveable and a compromise has to be made.  Having flat down walls is a good way of getting the best of both worlds.  The disadvantage is that it it certain configurations it has the potential to make running a roll off roof problematic and could compromise the stability of the whole structure.  It needs careful thought.