Dome or Roll-Off

We'll probably end up in or around Clarinbridge (I hope). Its far enough away from the City not to have too much of an effect.

Having a got a dome last year, I'll never look back

Cons,
Will miss random meteors,

Pros,
Wind protection,
Light pollution protection,
Sheer convenience !

I've never had any noticeable thermal problems thankfully, fibreglass is very bad at holding heat which is good for this application.
You don't have to miss the horizon, at least mine doesn't.

Make it as big as possible, of course that depends on the back garden, you can never make in too big, shelf and drawers are a big plus.
If it's too small you'll be regretting it pretty quickly!

Mine is about 9.5 feet across with a hatch just over 3 feet across, this gives me 1.5 + hours of RA travel before I need to move it, its has worked out very well and am happy with it.
We had a debate before we decided on the size, I was not going to go for it unless it was atleast 9.5 feet across, we dabbled on a 15 foot dome, but felt it would be difficult to turn due to its sheer weight.
I would have loved the 5 meter dome but settled on a 2.85 meter version.

Dave --

In my 10' ProDome I can notice some wobble on the 16" w/ dew shield in a light wind (10 - 15 mph?) with gusts. But the dew shield isn't really needed with any significant air movement, and without it I'm good till it gets up to a stiff, gusty wind (20 - 25 mph?). It's not really an issue for visual (only happens with gusts), but I wouldn't want to be trying to image in it.

At about 30 mph the dome needs to be closed up as the shutter system can't withstand much more while open.

I did have a shutter blow off a couple of weeks ago after one of the latch pins managed to rattle itself out (80 mph winds). I'll be moving to a more positive latching system (for now I'm using a cinch strap). Shutter is a bit cracked at the edge, but seems to still be working fine.

The dome also helps with local light pollution. Everyone's building around here, and they all want to show off their creations with big floodlights at night. Even from a mile away they can be distracting.

I definitely -do- miss the open sky, though. I haven't ever used a roll-off roof, but I'd have to guess that you'd be trading off a lot in the way of wind protection unless you had some pretty high walls (in which case you'd be trading off your horizon).

I observe each summer from a 12,500' pass in Colorado. Negative horizon to the south, crystal-clear skies with -no- light pollution. But I'm only about 100 meters off the road, and the passing car headlights can be a real nuisance. Everything's a trade-off, it seems.

-- Jeff.

Y'know, after what I said in my earlier post above, I think a roll-off roof would be best! Considering, yes, you have all the perks of the dome-shaped roof, you still can't quite beat having (almost) the entire sky in your eyesight to spot meteors and so on.

From a building-DIY perspective, roll-off is the easiest...

Seanie.

I went through these issues in my little head last year. Each has pros and cons. For me, I went with the roll-off-roof. A few of the major reasons in my head were

* Cost
* Seeing all the night sky
* Not having to move the dome AND the telescope each time you wanted to see something different
* Security

Each person will place difference levels of importance on these and draw their own conclusion. For me, it was to be a roll-off-roof but I can understand the attractions of the dome.

Not an easy decision to make.

BTW, there's a nice piece posted on Doc G's section of MAPUG regarding observatory design which was instrumental in my choice. It can be found here:

www.mapug-astronomy.net/ragreiner/ObsDes.html

-- Jeff.