Cant focus a skywatcher 250 auto

[roba]

I cannot get a a sharp image! I think maybe I need to fit an extension tube because I can get some sharpness by removing the eyepiece and holding it a few inches further out from the telescope tube. Or does the telescope need collimating? I would really appreciate some help if anyone has any ideas as to what I'm doing wrong.

[John]

Hi, welcome to SGL.

Which eyepiece or eyepieces does this happen with and what are you trying to focus on ?

I take it you have racked the focuser through it's full range ? (ie: as much as it will travel in each direction).

[hemihaggis]

hi and welcome , tell us a bit more about your scope and eyepieces ..im sure some clever clogs will pop along and help

[Moonshane]

there's both a 2" and a 1.25" connector for some reason with these scopes I think. are you using one?

[cyborg421]

I had this problem with a Skywatcher 250px Flextube and it was because the extension legs had dropped slightly. If you have a Flextube I should check this first.

Also I find if I put my Hyperion 10mm straight in as a 2" eyepiece it won't focus. If I use it with the 1.25" adapter it will.

Hope this helps.

Simon

[todd8137]

i had this problem with my 2" eps i got a 80mm ext tube it solved my problem

[roba]

Hello and thankyou so much for your help it is much appreciated! The problem occurs with 10mm and 25mm super plossl eyepieces which came with the Skywatcher Flextube 250 Auto. I am using the 1.25" eyepiece adapter but also have a 2" eyepiece adapter. My next plan may be to buy and try an 80mm extension tube. Could anyone suggest a suitable one and supplier? Unless of course there is a better plan of action! What are the extension legs and how do I find them ?

[Space Cowboy]

Something is not set up right on your scope. I have the same scope and eyepieces they should reach focus without any extension tube. Are you sure the telescope is fully extended i.e the flextube struts are pulled all the way out because if they are not then you wont get focus. What are you trying to focus on?

[xyz]

Hi, it would help if you give a little more info about the scope. I'm guessing a Dobsonian and I'm guessing a collapsible type and if so as cyborg421 suggests, perhaps the scope is not fully extended, thus the focal point lies outside the focus tube. It is most unlikely that the supplied eyepieces do not work with the scope, unless it is second hand and someone has swapped something around.

[George!]

I had this problem with a Skywatcher 250px Flextube and it was because the extension legs had dropped slightly. If you have a Flextube I should check this first.

Also I find if I put my Hyperion 10mm straight in as a 2" eyepiece it won't focus. If I use it with the 1.25" adapter it will.

Hope this helps.

Simon

Did you buy your Dob as an auto or was it Synscan from new?

[cyborg421]

Snyscan from new.

Simon

[stevetynant]

when you say you are using your 2 inch adaptor and the 1.25 inch adaptor - hopefully you have not got them both in at the same time? A mistake I stupidly made?

[littlebeagle]

What have you tried focussing on so far?

To be honest sounds like you haven't extended it fully, here are two pictures, first collapsed, second extended. Scope must be extended fully to get focus.

[RolandKol]

Hi Roba,

Have you found the solution?

I have exactly the same problem with the same model ( Skywatcher 250 PX Synscan DOB - Flexitube)

No focus with default 25mm and 10mm EP, I used 1.25 extension only.

It was always cloudy, so I tried to focus on the roof of the building which is aprox. 500meters away, but image was always blurry.

Ar night, I checked on the light of the window under the roof and had very strange result - I saw a triple blurry image of my secondary mirror with light background from the window.

I tried both EP 26mm and 10mm, the same. Funny, but the image has not changed a lot while I was changing the focus.

I thought maybe it is due to lack of collimation (see the file attached), but other members of the forum say that my Collimation is OK as far it is visible from the picture...

But I still cannot get focus, - I presume scope is fully extended as I heard Click sound.

[Cornelius Varley]

The OP hasn't visited SGL since Oct 2011 so I doubt you will get a reply.

 

[RolandKol]

Ach