Complete Newbie Failing to Set Up his Dobsonian

[JlginNZ]

My abject apologies for the insanely basic question I am about to pose, but I have had no success trying to find an answer to the problem I'm having with the most basic set up of my brand-new 10" Sky-Watcher Dobsonian here in New Zealand. I have been flummoxed when it comes to aligning the main viewing tube with the finder and the instructions that came with the telescope are less than helpful. 

Here's what I have been doing: In daylight, I have aimed the scope in the general direction of the moon (half-moon at the moment). With the finder I have no trouble finding it, so that's good. But when I look through the eyepiece (25mm) I see nothing but blue sky. I have tried to remove the eyepiece and just look through the open socket that the eyepiece assembly fits into, but then all I see is my eye looking back at me. I have tried to adjust the scope left and right, and up and down, hoping to find the moon through the eyepiece, but I have failed completely in that endeavour. Now, the moon was high in the sky while I was doing this, and I have no clue if I have the scope focused on infinity (though I have manipulated the focus wheel back and forth), so maybe that's the issue? And maybe doing it while the moon is half-full, and high in the sky has also made this more difficult than it needs to be? I am clearly doing something very, very stupid, but I have no clue what it is. Any help would be most gratefully received!!

[dannybgoode]

To align the finder scope it is sometimes better to work a bit in reverse and use a terrestrial object instead.  Do you have any telegraph poles, radio masts or the like visible but a mile or two away?  Get the scope focused on a far away land based object and then look through the finder scope.  As the finder scope it a wider field of view you are likely to see the object your scope is pointing at so adjust the finder so the same object is centred on the crosshairs.  It can be a bit hit and miss and also use the longest focal length eyepiece you have in the scope to give you a wider field of view there too.

Any questions just holler...

[Orange Smartie]

Hi. Apologies if I've missed this from your post, but it sounds to me as if you haven't actually aligned the finder along the same axis as the main scope. As @dannybgoode suggests, you'd need to adjust the finder itself, having first pointed the main scope at some terrestrial target. Once you've done that, the finder should have a series of screws that you would adjust in and out to ensure that the finder itself is exactly aligned with what you can see through the scope.

It's possible to set up the alignment at night but if you use a celestial object it will have an apparent motion relative to you, because of the earth's rotation, so you're unlikely to get it as accurate.

Edited March 6, 2021 by Orange Smartie
Typo

[Orange Smartie]

So I have checked online and it looks like the finder is adjusted with two screws against a spring-loaded button. 

Use a low power eyepiece (25mm) to aim the main scope at a terrestrial target. Don't point your scope at the sun!!!

Adjust the two screws on the finder until the finder is centered on the same object. 

Good luck!

Edited March 7, 2021 by Orange Smartie

[Tiny Clanger]

If  the finder alignment is the problem , here's a link to the step by step 'how to' I typed up for someone else : they had a red dot finder, if yours is an optical finder (like a tiny telescope) the process is the same, just centre the view in the finder rather than a red dot. 

Heather

 

[Pixies]

Hi,

have a look at this from 11:30 onwards. It's a different scope and they are using a right-angled finder, but you'll get the gist of it. Basically, in daylight, point the scope at something as far away as possible (using the eyepiece) and THEN align the finder to point at the same target. We're talking distant building / chimney / pylon , not the end of the garden.