Help With Dome Settings


I’ve never had a dome observatory and now I have one with rotation. Unfortunately I don’t have a clue on what to put in the “Observatory Settings”. I’m hoping you can spoon feed me abit as I have looked at the help file but I don’t really know what its asking for. I would like to go through each setting if you don’t mind:

"Diameter at Equator"

The above image shows two diameters either 80" or 92" - which do I select?

“North Offset” - The offset from the center of intersection of the Right Ascension and Declination axis to the center of the dome. If the RA/Dec intersection is north of the dome center this value is positive. If the RA/Dec intersection is south of this location the value should be negative.

I haven’t a clue what is being asked here. I always park my mount facing N. Help!!!

80 for your diameter (needs the dimension relative to the shutter)

This article describes these parameters wy better than I can:
Just look for the Dome synchronisation piece at the bottom.

So open that up. and now reference the following with the image:

  • North Offset, East Offset, Vertical offset are all relative to Point A (which is your mount’s intersection of Dec and RA Axis) to the Center of rotation of your Dome
  • Gem Offset - Is the measure from your mounts center of rotation to the center of your objective.

Also while these measurements should be close they do not have to be highly accurate. An inch or 5 here or there won’t greatly change the math behind this. your Gem offset is likely the most sensitive measurement. Also if you have a guide scope on top of your scope be sure to take that into account. You may want to split the difference between the two scopes.

Hope that helps,

Hi Jared,

Many thanks. Will get on the video ASAP. I only have the main scope and an OAG so no issue there.