Argggg... Urgent help needed

[earth titan]

Just collimated my scope (Skywatcher 150p) for the first time and everything looked spot on. Just taken it outside to align the sighting scope with the hope of a clear sky and I can't get the eyepieces to focus. Winding the focuser out fully, it almost needs to come out about 10mm more.

What have I done wrong?

[Doc]

Have you moved the eyepiece out of the focuser by 10mm to see if it comes to focus.

[Doc]

What you have done is collimated your scope and moved your primary to far up the tube. Wind your knobs fully down and then turn 1 turn each and recollimate.

[earth titan]

If I move it out, it does.

Will go and screw them back down. Can't say I moved them that far in the first place :iamwithstupid:but will report back when done.

[Moonshane]

although it should not be necessary, you can buy extensions for the focuser eg Astronomica 30mm 1.25 inch Extender | Adaptors | Accessories | Astronomica which can help solve your problem (and effectively convert thumbscrews to compression rings to help prevent damage to eyepieces).

[earth titan]

Twould appear that backing the screws off did the trick. Just need the sky to clear now.

Caught a glimpse of saturn in a break in the cloud and MeteoBlue suggests the sky might clear.

Just got to sit and see how the election goes..... Ho humm.

[John]

If you have been aligning your finder in daylight remember that astro scopes, especially newtonians, won't focus on terrestrial objects that are too close (ie: less than 100 meters) as they don't have the back focus required. They are designed for objects that are effectively at infinity.

You may find the adjustments you have made to the primary mirror position might make focussing on astro targets a little difficult - I might be wrong but just be aware of the possibility.

[TheThing]

As a rule of thumb, you should be using an object at least 500m away to align your finder, if not more.

[earth titan]

And I think I learnt this as well last night.......

Cos I had just done my first colimation, I assumed I had done something wrong. I think though now, after a bit of consideration and the help received on here, I can safely say my one brain cell must have been over exhausted.

[Moonshane]

I tend to align my finder and telrad on polaris at night. only takes a minute and works well.

[earth titan]

I was focusing on the chimney of my house, from the bottom of the garden which is about 30m away. Normally I focus on the ones behind our house which are about 60m away and I think this was the problem - not the position of the primary mirror.

Still you live and learn.

[Moonshane]

you live and learn.

that's what it's all about