Telescope Reviews: Importance of leveling?

Hi Dennis,

Firstly let me welcome you wholeheartedly to CN and to this Nexstar forum !

My impressions of the need for accurate (bubble) levelling follow somewhat different lines, but for what they are worth here goes !

In the first instance I have been told that accurate levelling when using Skyalign is all important. This may well be the case but since to my shame, all my attempts at this specific mode of alignment have always resulted in total failure, I never use it !

However, from what I've read and experienced, the alternative methods such as Auto Two Star (which I do constantly use), are not sensitive to spot on levelling and that mere "eyeballing" is sufficient.

As to Starizona's ideas on the subject of levelling and alignment I'm afraid do not agree.

The soundness of the maths is unquestionable but the notion that for the sake of accuracy the fastest alignment possible must be made, is a myth. Indeed there's a quote on this subject by Mike Swanson: argueably the Nexstar Guru", in his book, "The Nexstar User's Guide".

"Quote" --- "You must work as fast as possible between centering the first and second alignment stars".

"Sounds good, just isn't true. In a test of this statement, I started an alignment, centering the first star, and then waited one hour before centering the second star. This caused no problems; GoTo and tracking behaved normally. Obviously the hand control keeps track of the amount of time between centering one star and the next and incorporates this factor into its calculations".

---"Unquote"

This is also my experience although I've never waited for an hour before completing an alignment !

My understanding is that in aligning two stars, such provides the on board computer with two celestial reference points from which it then works out the position of every other object within its vast data base.

However the speed at which these alignment points (stars) are entered is irrelevant because tracking does not begin until after the second star has been aligned, entered and "Align Success" proclaimed by the hand controller.

Having therefore "logged" the first star; if there is a time delay between this action and aligning the second star, the first star has of course "moved on". But so has the second star and in the exact same relationship to the first. Thus the "sky picture" can only be built after the second star has been aligned.

Going back though to accurate levelling, I'm certainly in favour of anything which may help the 'scope user achieve the best from his or her 'scope but there is perhaps a fine line to be drawn between effort and gain.

My approach to this is that my GoTos always fall within the field of view of a 20mm standard Ploessl eyepiece (ca.30 arcmins) and most times are pretty near to its centre. If need be, I refine this and carry on. I therefore have no personal preoccupation with seeking the "nth" degree of accuracy with regard to this particular aspect.

As usual, just my opinion on my way of doing things which may certainly not be those of other folks !

Best Regards,
Tel

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Truth is the cubed root of Verbosity.