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1: The scope specification page

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Cyrille-de-Brebisson edited this page Jan 9, 2019 · 2 revisions

On this page you will enter all the basics of your scope. Name it (if you want, but if you leave the “default” and start creating more scopes, you will have a number of “default” in the selection box).

On the right of the scope name you will find the “Delete” button. Press there to delete the scope! Add comments if you want to (they can be multi line).

Depending on what you want to do, you will need to enter more or less information in this page. Must enter information include: Mirror diameter, focal length, secondary small diameter and distance from secondary to focal plan (or focal-mirror to secondary distance). The focal length can be entered as a distance, a f ratio or a radius of curvature.

If you want to do mirror cell calculations, you will need to add the mirror thickness and material properties (density and the like). Fortunately, if you use a standard material, you can just select it from the drop down to auto populate these fields.

Entering the 'top length', which is the length from the secondary center to the top of the tube as well as a view angle, which is the max opening you want on the stars will calculate the inner radius of your tube.

Should you also populate the focusser height, it will tell you how much said focusser can move by before entering the light cone.

Anyhow, once you have entered all you care about, the system will automatically calculate the rest.

  • max zoom (if you try to zoom more, interference from the mirror edge will start blurring things).
  • max visible magnitude (assuming that your eye can see to mag6!)
  • max resolution (which correspond to max zoom if you think about it!)
  • improvement over your naked eye (ie: scope can gather n times more light than your 5mm pupil!) It does take the secondary into account.
  • Focal info (enter one of 3 to get the 2 others). Internally, only the focal length is stored. The others are recalculated on the fly.
  • sagita (the depth of the parabola in the middle of the mirror)
  • When doing your collimation, the center of the secondary should be offsetted toward the primary. The distance will be indicated here. Note that if you visually center the secondary in the focusser, this is done automatically.
  • primary mirror weight
  • the minimum radius at the top of the scope to allow your view angle
  • the allowed movement of your focusser before it enters the light cone with the required view angle.

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