Quote:
Originally Posted by g__day
Gary, I'm sure you are correct!
Thanks for that - I abreviated because I use the Sky6 PE now with Tpoint add on - and Tpoint states (pg 19 of the user manual) "You must map at least six points before Tpoint is able to perform a "fit" and begin to improve the pointing of the telescope". I took the author's own words that Tpoint improves the pointing as understanding it does it directly, but I really don't mind if its doing it indirectly - such so long as it's done!
Even if Tpoint only shows me how pointing errors vary across the sky - that'll give me leads to what challenges I face. So if it is mirror shift I can either try and mod the scope to remove it, change scopes, live with it or try and model it out if that is possible.
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Thanks Matt,
In the case of TPOINT with TheSky6, the pointing corrections will be performed
by the pointing kernel within TheSky. But as a user you don't necessarily need
to know this as TheSky integrates TPOINT nicely and what piece of software
is doing what is therefore opaque.
Where the "at least six points" requirement comes from is that by default,
TPOINT with TheSky automatically applies the terms ID, IH, MA, ME, CH and NP.
Just as you require six unique equations to solve six unknown variables, you need
at least six data points to make an estimate of solving these six terms. Strictly
speaking, you could get away with four if you turned off NP and CH, which
I don't recommend you do. ID, IH and MA and ME should always be used.
Recommend you try the "Suggest" button feature for adding additional terms if you have
not done so already. There can be subtle things such as gear eccentricities that
TPOINT's richer set of terms can often pick up that aren't available in the
package you were using previously.