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Best alignment process for the Celestron NexStar 8SE — 2 Comments

  1. I understand the Celestron AVX does not track in DEC only RA so I have a question, when in the Alignment mode and have UP/Right buttons to put the alignment star into the center of the Meade 9MM Lighted reticle I see the star sloiwly drift out of center before I press ALIGN and continue to the next step.

    Does this indicate a mechanical problem or does ALignment Mode not track the star this allowing it to drift out of center if the ‘align’ button is not pressed right away to continue to the next alignment star ?

    • Essentially you are correct about the tracking, and it is not a mechanical problem. Until you are fully aligned i.e. both stars in a two-star process for example, it can’t track anything. So it is staying “fixed where you leave it” and the stars will move out of the eyepiece. This is true of any EP, but you REALLY see it with an eyepiece at that degree of magnification. I have a 10mm lighted reticle, and it is almost impossible to align to the exact centre and then press the two buttons so “quick” to get the alignment. But there are two things to remember:

      a. If you notice that it is drifting from upper right to lower left, for example, then you can use your final movements to put it in the upper right. And then press your buttons as it drifts past the centre on its way to lower left. I frequently would put it about halfway from centre to the edge (with the correct up/right final movements to put it there) and then as it passed through centre, press the align button.

      b. It isn’t a popular notion, but remember you’re dancing on the head of a pin here at that level of magnification — the difference between dead centre and a little bit off centre is not statistically significant. For the 8SE that I have, it is assumed that you are using a 25mm lens. Which means the equivalent distance of being dead centre at 9mm vs. half way to the edge at 9mm is almost nothing in the 25mm lens. Put differently, it would be the difference of centreing perfectly on a star at 25mm vs. being a pinhead away at 25mm. That’s not going to make that much difference for finding things.

      You’re more likely to have errors introduced by the scope not being level than being just a bit off on the lighted reticle. In fact, for mine, I’ve stopped using it, it was just too much trouble. Instead, I use the 25mm lens with the doughnut method (unfocusing enough so it is a big round doughnut and centreing that in my EP). I’ve been getting pretty dang good alignment as a result. Not perfect, but it’s not guaranteed to be perfect.

      If your alignment is off after using a 9mm reticle, then that isn’t likely your cause…

      Paul

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