[Kstars-devel] Eyepiece view success story!

[Akarsh Simha]

Dear users and developers,

I'm pleased to say that the new eyepiece view feature in KStars saved
me a _lot_ of frustration and time while observing on the field last
night.

I observe with a large Dobsonian telescope, which has a focuser on the
left side of the tube when looking along the direction in which the
telescope is looking, and is not angled. For this setup, I have
field-tested the latest "Dobsonian" preset in the Eyepiece View
feature that I just pushed to master a few minutes ago. I left
eyepiece view on this setting all through, and it just worked -- the
field I was seeing in the eyepiece was exactly as predicted in KStars!
(Note that for it to work correctly, time must be synced with current
time in KStars, and KStars must be in horizontal coordinates mode).

The logic is very simple, yet its value on the field is profound --
the sky has altitude pointing up and azimuth pointing right; the
telescope's mirror inverts this field and presents this in the
eyepiece. Then, when viewing on a large Dob, the angle between the
focuser, the natural coordinates of the telescope are tilted by an
amount equal to the altitude of the telescope, from the ground
reference frame.

The advantage of using it correclty is that there is no more "setting
the orientation correctly" or mapping the field to the chart by
relative positions and orientations, because the EP view just shows
you the right orientation. This saves a lot of time and frustration if
you're star hopping.

Also to be noted is that my setup is on an equatorial platform, which
means it gets tilted by a few degrees, but this tilt is too small to
be significantly noticable and the EP view still works well.

>From users of KStars, esp. visual observers, I would greatly
appreciate feedback on how the feature works for you, and what other
presets might be good to code. It's hard for me to think up the
logic/math for these things, so any help there would also be
appreciated!

Regards
Akarsh