Is there something wrong with my scope?

[SweetLeaf]

The past few nights when I've been out viewing when I look at the moon at first I can't see anything and then it slowly comes into view from one side to another.

At first I'll just be able to see a bit of one side, and the rest of it is covered by black and then the black just becomes less and less. It only lasts for a few minutes.

Just wondering what was up with this? Lol.

[david o]

It might help if you could tell us what 'scope you have & what mount it's on.

Does it happen with one eyepiece, or all your EPs?

Is it a manual mount, or is it motorized?

Were you moving your eye around a lot in relation to the EP?

Does it happen with star-fields too, or just on the Moon?

[SweetLeaf]

NexStar 114SLT (item #31143) / Spring Clearance Sale / Products / Celestron.com

It was tracking at the time and kept the moon directly in the center.

It happens with more than one eyepiece, and I'm pretty sure it happens with more than just the moon. Sometimes I won't be able to see Saturn and so I'll try looking at the moon and that's when it just looks like it's not there, so I search around that area for a bit looking for the moon and then I'll point it back at the moon and I can see just a little bit of the moon which seems to be cover by a blurry blackness above it.

[Merlin66]

If you live near Cobham, bring it over and I'll check it out for you.

If it's a recent purchase contact the supplier!

Ken

[david o]

Not sure.

But it sounds like it could be kidney beaning. When part/all of the field of view blacks out because your eye isn't lined up on the EP's exit pupil.

Especially if it happens with the shorter focal length (higher mag.) EPs, as they have narrower exit pupils..

If that's the case, then, once you can see the Moon clearly, try keeping your eye motionless in relation to the EP as the 'scope tracks.

HTH

Edit: Just had a thought - is the finder 'scope properly aligned?