Dob 200P 2” eyepiece adapter

[banjaxed]

I am thinking of trying a 2” eyepiece in my Dob but the adapter that comes with the scope was missing from mine. Could anyone please let me know what length the adapter needs to be.

Thanks in advance.

[Knighty2112]

Might help if you tell us what make and model dob you have?  

[banjaxed]

Sorry, It’s a Skywatcher 200P.

[Louis D]

You could try the TS-Optics Skywatcher 2" adapter.

[banjaxed]

1 hour ago, Louis D said:

You could try the TS-Optics Skywatcher 2" adapter.

Thanks for the reply, but I think it needs to be a certain length to obtain focus.

 I was hoping someone with the same scope could tell me what length it is.

[pregulla]

I am using 40mm with mine. All 2" eyepieces I tried come to focus with it (Aero ED 35mm, Meade QX 26mm, ES82 30mm, SkyWatcher SWA70 32mm). I also use it with 1.25" to 2" adapter which is about 10mm tall and all my 1.25" eyepieces come to focus. I also know that 50mm was too much for SkyWatcher SWA70 32mm, I didn't try with others.

[banjaxed]

6 minutes ago, pregulla said:

I am using 40mm with mine. All 2" eyepieces I tried come to focus with it (Aero ED 35mm, Meade QX 26mm, ES82 30mm, SkyWatcher SWA70 32mm). I also use it with 1.25" to 2" adapter which is about 10mm tall and all my 1.25" eyepieces come to focus. I also know that 50mm was too much for SkyWatcher SWA70 32mm, I didn't try with others.

Thank you very much for the info, I will order the 40mm adapter.

[Star Struck]

I have one 2" eyepiece in my 200P dob that needs a 50mm, but all the rest are happy with 35mm.

[banjaxed]

1 hour ago, Star Struck said:

I have one 2" eyepiece in my 200P dob that needs a 50mm, but all the rest are happy with 35mm.

That has made things more uncertain. Has anyone here got the original adapter supplied with the telescope ?

[Star Struck]

I have. It is 35mm.

 

[banjaxed]

1 hour ago, Star Struck said:

I have. It is 35mm.

 

Great, thank you very much for the info, much appreciated.

[bingevader]

3 hours ago, Star Struck said:

I have. It is 35mm.

 

?

Mine is 1 and 7/8th of an inch or about 47mm!

[bingevader]

21 hours ago, Louis D said:

You could try the TS-Optics Skywatcher 2" adapter.

Check your drawtube has a screw thread then, as that adaptor screws straight into it.

I doubt I'd reach focus if I only pulled my EPs out by 12mm and fastened them there!

[bingevader]

That's what mine looks like.

[banjaxed]

2 hours ago, bingevader said:

Check your drawtube has a screw thread then, as that adaptor screws straight into it.

I doubt I'd reach focus if I only pulled my EPs out by 12mm and fastened them there!

I checked the drawtube and it does not have a thread.  I have located a 40mm extension adapter which I will order and see how it goes.

Many thanks to all who replied with all your helpful suggestions.

[cletrac1922]

Banj

First of all welcome from Land Down under

I have SW 250 flex Dob scope

Will check mine tonight, as doing viewing of Harvest Moon tonight, with local television station

I also have 2" barlow, and had never been able to get Dob to focus using it, need extension tube

Not sure what the advantage is using 2" eyepieces, as opposed to 1.25"

John

 

[bingevader]

19 hours ago, cletrac1922 said:

Not sure what the advantage is using 2" eyepieces, as opposed to 1.25"

 

FOV and drift time to name but two!

[Louis D]

On 12/09/2019 at 21:05, cletrac1922 said:

Not sure what the advantage is using 2" eyepieces, as opposed to 1.25"

As @bingevader says, much wider true field of view (TFOV).  You can only take in a 27mm diameter view of the image plane with a 1.25" eyepiece, but a 46mm diameter view with a 2" eyepiece.  That's a 46*46/27*27=2.9x more viewable area.  For instance, it makes viewing large objects like the Pleiades and Collinder 70 much easier in moderate focal length telescopes.

[bingevader]

I posted this elsewhere.

It gives you an idea of the difference.