Extension Tube

[Littleguy80]

My dob has a lovely Baader Steeltrack Focuser on it. I was given a basic extension tube when I bought the scope to account for the focuser being much slimmer than the original focuser. That extension tube is fine with the 2” to 1.25” adapter but isn’t suitable for 2” eyepieces as it doesn’t have a means of clamping onto the eyepiece. It just has a basic screw. I was looking at getting the extension tube below:

https://www.firstlightoptics.com/adapters/moonlite-15-focus-extension-tube.html

I like it as it has a compression ring and is threaded for 2” filters. Will be nice to swap eyepieces in and out without having to move the filter across.

Does anyone have any experience of this extension tube? Any good alternatives that could be recommended?

[Handy_Andy]

If your revelation barlow lens is the 2" version why not unscrew the bottom magnifying element? Mine will take a 2" filter, job sorted £45 saved

[cloudsweeper]

Neil - an extension tube might be necessary to achieve focus in some situations, but as for taking a filter, you could insert that in the drawtube end of the diagonal (although this is not always convenient, depending on how it fits) OR at the bottom of the tube at the other end, being careful to check that the EPs don't go too far in!  They usually don't.

Maybe the extension tube would be easier and safer though!

Doug.

[Littleguy80]

4 minutes ago, Handy_Andy said:

If your revelation barlow lens is the 2" version why not unscrew the bottom magnifying element? Mine will take a 2" filter, job sorted £45 saved

Good idea, sadly it's on the 1.25" version. I like your thinking though  

[Littleguy80]

7 minutes ago, cloudsweeper said:

Neil - an extension tube might be necessary to achieve focus in some situations, but as for taking a filter, you could insert that in the drawtube end of the diagonal (although this is not always convenient, depending on how it fits) OR at the bottom of the tube at the other end, being careful to check that the EPs don't go too far in!  They usually don't.

Maybe the extension tube would be easier and safer though!

Doug.

Thanks Doug. It could be my understanding of the terminology but I don't think the dob uses a diagonal? The filter option seemed like a nice additional benefit of the something I was going to need anyway

[alanjgreen]

Or a nice clicklock extension

https://www.firstlightoptics.com/adapters/baader-2-inch-click-lock-cl-extension-47mm.html

I have not tried this extension personally, but I do love the clicklocks!

More detailed info here

https://www.teleskop-express.de/shop/product_info.php/info/p2433_Baader-2--extension---47mm-length---ClickLock.html

 

[cloudsweeper]

41 minutes ago, Littleguy80 said:

Thanks Doug. It could be my understanding of the terminology but I don't think the dob uses a diagonal? The filter option seemed like a nice additional benefit of the something I was going to need anyway

Doh - that's just me with my frac and SCT!  But worth bearing in mind for something other than your Dob I suppose Neil!

Doug.

(12" Dob to be my next 'scope.  I've already got the cap and the Cheshire!! )

[scarp15]

The Moonlite is an excellent extension tube, I use one on my 8" dob and previously had one for a 12" dob. As you say, useful for attaching filters.

[Littleguy80]

1 hour ago, cloudsweeper said:

Doh - that's just me with my frac and SCT!  But worth bearing in mind for something other than your Dob I suppose Neil!

Doug.

(12" Dob to be my next 'scope.  I've already got the cap and the Cheshire!! )

Exciting times, Doug. You’re going to have such a great time with a big dob! Can’t wait for those reports to start rolling in  

[Littleguy80]

1 hour ago, alanjgreen said:

Or a nice clicklock extension

https://www.firstlightoptics.com/adapters/baader-2-inch-click-lock-cl-extension-47mm.html

I have not tried this extension personally, but I do love the clicklocks!

More detailed info here

https://www.teleskop-express.de/shop/product_info.php/info/p2433_Baader-2--extension---47mm-length---ClickLock.html

 

Thanks Alan. The click lock looks really nice. I think if I could have that with the filter thread it would be a definite winner. 

[Littleguy80]

1 hour ago, scarp15 said:

The Moonlite is an excellent extension tube, I use one on my 8" dob and previously had one for a 12" dob. As you say, useful for attaching filters.

Awesome. Thanks, Iain. Was hoping someone would have some actual experience of it  

[alanjgreen]

1 hour ago, Littleguy80 said:

Thanks Alan. The click lock looks really nice. I think if I could have that with the filter thread it would be a definite winner. 

It has a filter thread according to the teleskop express text. It's in the bullet points under the picture.

Just press the Union Jack to switch text to English...

there is a picture of the telescope side on this eBay link which DOES show a filter thread...

https://www.ebay.com/itm/Baader-2-Clicklock-Eyepiece-Extension-Tube-with-47mm-Extension-EXT-CLSC-2956247/142562725946?hash=item213166903a:g:LNsAAOSwyXNaBjC5

[Littleguy80]

Just now, alanjgreen said:

It has a filter thread according to the telescope express text

 

Brilliant. I must have missed that! Let me have another read! 

[Littleguy80]

7 minutes ago, alanjgreen said:

It has a filter thread according to the telescope express text

 

You’re right. Not mentioned on the FLO description so I’ve pinged them an email for confirmation 

[Littleguy80]

15 hours ago, alanjgreen said:

It has a filter thread according to the teleskop express text. It's in the bullet points under the picture.

Just press the Union Jack to switch text to English...

there is a picture of the telescope side on this eBay link which DOES show a filter thread...

https://www.ebay.com/itm/Baader-2-Clicklock-Eyepiece-Extension-Tube-with-47mm-Extension-EXT-CLSC-2956247/142562725946?hash=item213166903a:g:LNsAAOSwyXNaBjC5

FLO confirmed the filter thread is there so looks like that’s the one  Great suggestion, Alan. Thanks to all for the responses  

[Littleguy80]

My Baader ClickLock extension tube arrived today from FLO. Looks very smart. I had an Amazon voucher to use up so I also picked up the ClickLock 2” to 1.25” adapter. The ClickLock system seems really nice. Should make for nice and easy eyepiece changes in the dark. Thanks again to all who contributed to this thread