Amaranthus
22-11-2015, 03:49 PM
So, I've been meaning to write this up for a while...
I moved to southern Tasmania about a year ago. My property is 40 ha of bush in the Huon Valley (about 45 km from Hobart), with my house and an extensive cleared area around it situated on a ridgeline overlooking the Huon river at about 100 m elevation. This lifts me above the majority of the fog that tends to form in winter, and allows for my horizon to be clear and uninterrupted down to about 5 degrees elevation in the south and west, 8 degrees in the east, and 15-20 degrees in the north (the ridgeline extends across this bearing, but with all nearby trees cleared, it maintains a quite even and consistent profile).
The skies are incredibly dark (Bortle rating a safe 2, and skirting a 1 I reckon, except when the Aurora is active!). Truly a joy for LRGB imaging and for hunting out the faint fuzzies! The only downside to my setting is that Tassie weather can be a little fickle - whilst some nights are just perfect, for many others the clouds part rather randomly for a few hours and then close in again. This means one has to be in a position to take full advantage of opportunity as it arises! It also makes the nightly setup/tear down a drag, especially for imaging where a PA is required. Just too 'risky'. So, I was strongly motivated to build an observatory.
My goal was a little unit that was relatively cost effective, but sturdy (strong winds here sometimes!), could leave two mounts set up permanently side-by-side (one for AP, one for visual), and was easy/quick to get going and to pack up. Given that the observatory is located 10m from my back door, I was not interested in pursuing full automation - I'm happy to be on hand when imaging, either sitting in the observatory when I want to enjoy the night skies (often using my IS binos, whilst the imaging is happening), or else for just checking the gear every hour or two when I decide to go inside the house. I clearly wanted to be able to park/pack-up (and conversely, to start an imaging session) as quickly as possible, so as to always be in a position to beat the weather.
Anyway, the attached images show the results. The first one is my early sketch design, and the photos show the final results. This setup has been operating for about 3 months now, and I'm extremely happy with the balance struck. I was particularly pleased with the 1-piece fold off roof, which was designed by my builder, Matt Jungmann - the frame and lever are made of welded aluminium and it is covered a lightweight but super-tough/weatherproof/heat reflecting translucent plastic sheeting that is used for gazebos etc. It is hinged sturdily at the back, and lifted using an aluminium arm (that otherwise sits clipped to the side wall). This roof-arm has terrific leverage, making the fold-off action incredibly smooth and almost effortless, even when at the maximum point. It also acts as a stand when the roof is open, as can be seen in one of the images. When closed, it is sealed completely from water ingress using a soft rubber lining like that used in car doors, and pulled down (handles) and bolted tight on the inside. Opening/closing setup takes all of 30 seconds... It has survived the worst that the southern ocean squalls can throw at it with not a mark!
Inside is a concrete slab, with a permanent roof covering half of the observatory, which includes a desk, drawers, shelves etc. to store all of my gear. Footprint of the slab is 2.5 x 3.5 m. There is no cut-off of the horizon at all when imaging. I use a fixed tripod on vibration-free pads for my AZ-EQ6, rather than a mounted pier--for various reasons--and this has yielded fine tracking/guiding results (typically RMS of 0.2-0.4").
Anyway, if anyone has any questions/comments on this, I'd be most happy to answer!
I moved to southern Tasmania about a year ago. My property is 40 ha of bush in the Huon Valley (about 45 km from Hobart), with my house and an extensive cleared area around it situated on a ridgeline overlooking the Huon river at about 100 m elevation. This lifts me above the majority of the fog that tends to form in winter, and allows for my horizon to be clear and uninterrupted down to about 5 degrees elevation in the south and west, 8 degrees in the east, and 15-20 degrees in the north (the ridgeline extends across this bearing, but with all nearby trees cleared, it maintains a quite even and consistent profile).
The skies are incredibly dark (Bortle rating a safe 2, and skirting a 1 I reckon, except when the Aurora is active!). Truly a joy for LRGB imaging and for hunting out the faint fuzzies! The only downside to my setting is that Tassie weather can be a little fickle - whilst some nights are just perfect, for many others the clouds part rather randomly for a few hours and then close in again. This means one has to be in a position to take full advantage of opportunity as it arises! It also makes the nightly setup/tear down a drag, especially for imaging where a PA is required. Just too 'risky'. So, I was strongly motivated to build an observatory.
My goal was a little unit that was relatively cost effective, but sturdy (strong winds here sometimes!), could leave two mounts set up permanently side-by-side (one for AP, one for visual), and was easy/quick to get going and to pack up. Given that the observatory is located 10m from my back door, I was not interested in pursuing full automation - I'm happy to be on hand when imaging, either sitting in the observatory when I want to enjoy the night skies (often using my IS binos, whilst the imaging is happening), or else for just checking the gear every hour or two when I decide to go inside the house. I clearly wanted to be able to park/pack-up (and conversely, to start an imaging session) as quickly as possible, so as to always be in a position to beat the weather.
Anyway, the attached images show the results. The first one is my early sketch design, and the photos show the final results. This setup has been operating for about 3 months now, and I'm extremely happy with the balance struck. I was particularly pleased with the 1-piece fold off roof, which was designed by my builder, Matt Jungmann - the frame and lever are made of welded aluminium and it is covered a lightweight but super-tough/weatherproof/heat reflecting translucent plastic sheeting that is used for gazebos etc. It is hinged sturdily at the back, and lifted using an aluminium arm (that otherwise sits clipped to the side wall). This roof-arm has terrific leverage, making the fold-off action incredibly smooth and almost effortless, even when at the maximum point. It also acts as a stand when the roof is open, as can be seen in one of the images. When closed, it is sealed completely from water ingress using a soft rubber lining like that used in car doors, and pulled down (handles) and bolted tight on the inside. Opening/closing setup takes all of 30 seconds... It has survived the worst that the southern ocean squalls can throw at it with not a mark!
Inside is a concrete slab, with a permanent roof covering half of the observatory, which includes a desk, drawers, shelves etc. to store all of my gear. Footprint of the slab is 2.5 x 3.5 m. There is no cut-off of the horizon at all when imaging. I use a fixed tripod on vibration-free pads for my AZ-EQ6, rather than a mounted pier--for various reasons--and this has yielded fine tracking/guiding results (typically RMS of 0.2-0.4").
Anyway, if anyone has any questions/comments on this, I'd be most happy to answer!