Can´t reach focus with eyepiece in 150-PDS

[MartinFransson]

Hi!

Being a total newbie when it comes to telescopes, I hope I´m doing a very simple mistake

I just got a used Sky-Watcher 150-PDS but I can´t get focus using the 2" 28mm eyepiece, unless I move the focuser all the way out and then installing the eyepiece not inserted more than maybe 2 mm in the focuser. See the attached pic, does that look right? Doing like that, I can focus on objects maybe 5 km away, not closer.

[MartinFransson]

Just got an email from the seller, saying he had a 2" extension tube he didn´t know if it was for this scope. Could that be the problem?

[ronin]

Makes half sense, the PDS is aimed at imaging and the focuser is in closer to enable a DSLR to gt the sensor to the focal plane.

I think you have to add a short extension tube when using an eye piece.

Also 2" eyepiece tend to need the focuser to be at a different position to the 1.25" eyepieces.

Your second post appeared, a 2" entension tube sounds about right. :grin:

[happy-kat]

I believe so reading posts.

The telescope is designed to focus natively with a camera so with eyepieces you may need a 2 inch extension.

[nightfisher]

Yes, it should hve been sold with 2" extension tube, also should have a "top hat" 1.25 ep holder

[MartinFransson]

Thanks! Feel a lot better now

The "top hat" was included and the seller promised he´d send the extension tube to me tomorrow.

[Yearofthegoat]

Yep, did that with mine. I also found out the hard way that you use only one extension or the other depending on the type of EP - i.e. you don't stack the extensions when using 1.25" EPs.

Fun this astronomy lark!