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#26 SteveG

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Posted 22 August 2013 - 03:19 PM

Scopestuff has the barrel extensions:
http://www.scopestuff.com/ss_epe2.htm

#27 Starman1

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Posted 22 August 2013 - 04:05 PM

Some examples of barrel extensions:
Baader Fine Tuning Ring--14mm
Baader Fine Tuning Ring--28mm
TeleVue Barrel extender--30.4mm
2" filters with glass removed--average 5mm
And, of course, they could be combined......

#28 Scanning4Comets

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Posted 22 August 2013 - 05:00 PM

Just slightly. I have among other a Nagler 11mm T1 and the smoothies NJ Televue widefield series. I have about 30 eyepieces, recent and vintage. Do you have some ?


Hi Pollux556,

Unfortunately I do not have any vintage eyepieces. Like Randy said, I swap them out a lot to try others. If I had of saved every eyepiece I have bought, I would have hundreds! I just have four right now.

As for vintage eyepieces, or older offerings, I have owned a 16mm flat top Konig, a 2" 32mm Edmund Erfle, a 32mm Konig, a few Criterion eyepieces, maybe a few more. Wish I had of kept them also!

I think Bill Rose AFAIK, is the king of the eyepiece collectors, I'm prob the king of buying and selling, LOL!

#29 Pollux556

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Posted 23 August 2013 - 07:03 AM

If you ever bought a used eyepiece, chances are Marcus had it at one point or another.....

Marcus is like the King of Eyepiece Swappers......

and we all owe him a thanks for that.........

he'd done some pretty decent reviews of various eyepieces written more on a laymen's terms then a lot of techie stuff.


I believe, with the number of posts he has. :lol:

#30 Pollux556

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Posted 23 August 2013 - 07:26 AM

Just slightly. I have among other a Nagler 11mm T1 and the smoothies NJ Televue widefield series. I have about 30 eyepieces, recent and vintage. Do you have some ?


Hi Pollux556,

Unfortunately I do not have any vintage eyepieces. Like Randy said, I swap them out a lot to try others. If I had of saved every eyepiece I have bought, I would have hundreds! I just have four right now.

As for vintage eyepieces, or older offerings, I have owned a 16mm flat top Konig, a 2" 32mm Edmund Erfle, a 32mm Konig, a few Criterion eyepieces, maybe a few more. Wish I had of kept them also!

I think Bill Rose AFAIK, is the king of the eyepiece collectors, I'm prob the king of buying and selling, LOL!


I owned some EP like Orion Expanse, UO ortho ect. May be 100 EP have passed through my eye :)
I don't know Bill Rose. What is AFAIK ?

#31 csrlice12

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Posted 23 August 2013 - 07:49 AM

AFAIK, As Far As I Know.....(as far as I know).

#32 MrFancypants

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Posted 23 August 2013 - 08:16 AM

You are looking for one of these if you can't move your mirror enough:
http://www.telescope...elescope-Foc...

#33 ArtVandelay

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Posted 23 August 2013 - 11:59 AM

You are looking for one of these if you can't move your mirror enough:
http://www.telescope...elescope-Foc...


That piece came with my scope. I saw that and then looked at my focuser, and that is the exact piece that is currently on there. This is what I need http://www.telescope...e/p/5124.uts...
The only thing is that I would prefer it to have a compression ring. Televue makes one, but it is $60. I was curious if anyone knows of another company that makes one with a compression ring for cheaper.

#34 SteveG

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Posted 23 August 2013 - 12:13 PM

Here's a bunch of barrel extensions by Blue Fireball:

http://agenaastro.co...rs/spacers.html

#35 Scanning4Comets

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Posted 23 August 2013 - 01:23 PM

I think an extension tube maybe just what the doctor ordered!

Left pic: No extension tube. Right pic has a 35mm Blue Fireball extension tube added in the focuser. The 35mm Extension Tube has a compression ring, and it is only $25.95 :jump: If it is too long after you add the extension tube, all you will have to do to reach focus is rack the focuser inwards. :cool:

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#36 Scanning4Comets

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Posted 23 August 2013 - 01:36 PM

Here it is.

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#37 Starman1

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Posted 23 August 2013 - 02:20 PM

The math works out bad for an extender tube as pictured:
Focuser maximum out--1.5"
Eyepiece Needs an extra 0.33" out
Extender tube adds about 2" (maybe a little more) in pullback (full length of 2" barrel on eyepiece since none of the eyepiece is now inside the focuser).
Now focuser needs to move in by 2" - 0.33" = 1.67"
The eyepiece will run out of in-travel.

In this situation, a barrel extender is a better choice, because the eyepiece can pull out the necessary 1/3" and still leave over 1.5" of the original eyepiece barrel in the focuser PLUS the length of the barrel extension.

A focuser extension tube is desirable when you need an inch or more of pull-back for the eyepiece.

#38 Scanning4Comets

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Posted 23 August 2013 - 02:26 PM

Don,

I need to bring my eyepiece out about 1/2" with my 9mm or 14mm ES 100's to reach focus. I can reach focus with the O-rings in place or with the extension tube, (without the O-Rings), for either eyepiece, and I still have a lot of play inwards. I think the extension tube will work, unless I am mistaken because he needs 1/3" of out travel?

#39 csrlice12

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Posted 23 August 2013 - 02:31 PM

Haven't got the 9mm in yet, but have been able to reach focus with my 10XTi with the dual speed Scopestuff focuser with both the 14 & 20mm ES100.

#40 Pollux556

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Posted 23 August 2013 - 03:08 PM

AFAIK, As Far As I Know.....(as far as I know).


Thanks ! :o

#41 Starman81

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Posted 23 August 2013 - 10:56 PM

Here's a bunch of barrel extensions by Blue Fireball:

http://agenaastro.co...rs/spacers.html


I used to use my GSO 2" Barlow without the barlow element as my 'extension tube' when I had the ES100 9mm. It worked well, but what a moment arm!

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#42 Mike B

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Posted 24 August 2013 - 12:18 AM

Ya- you don't wanna whack into that in the dark... unless you were wanting a focuser upgrade. ;)

#43 bherv

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Posted 24 August 2013 - 10:39 AM

I recently changed out the stock focuser on my 5" f/5 Skywatcher and replaced it with a 2 speed Crayford. I found I needed to pull my ES eyepieces about 1/4" out of focuser to reach focus. I then tried to use a 2" extension tube but I did not have enough in focus. I was about to buy a shorter extension tube when I realized I had a non-tunable Paracorr top sitting on my dresser. It adds about 1.5" to the racked out height so I should have enough in focus with my ES eyepieces. I put a piece of clear packing tape on inside of Paracorr barrel to protect eyepiece from getting scratched by the set screw
Barry

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#44 kkokkolis

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Posted 24 August 2013 - 10:54 AM

Markus, do you use the original Skywatcher 2" adapter, the one that the scope was sold with?

#45 ArtVandelay

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Posted 24 August 2013 - 11:07 AM

Yep. This is exactly what I needed. Thanks Scanning4Comets!

http://agenaastro.co...m-1-38-exten...

#46 Scanning4Comets

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Posted 24 August 2013 - 03:45 PM

Markus, do you use the original Skywatcher 2" adapter, the one that the scope was sold with?

--------------------
Konstantinos


Hi kkokkolis,

No, I don't use that adapter. I completely replaced the stock focuser with a Zhumell crayford focuser and then I ordered the dual-speed crayford focuser upgrade kit . The crayford focuser is so much better and the dual speed focuser upgrade kit is a blessing in disguise. When you use the dual speed part, the jiggles I had when focusing before are cut down a lot. I don't need an extension tube for any of my eyepieces. If you go back to page one of this thread, you can see a pic of my focuser. I have a pic on the left of the focuser itself, and a pic to the right showing a 35mm Blue Fireball extension tube which I use to mount my filters to so I don't have to screw my 2" filters onto any of my eyepieces. I just did the double picture to show what it looks like having a 35mm extension tube on the focuser.

I have a 2" Orion Ultrablock and a 2" 13% Neutral Density filter. I plan on getting a 25% ND filter and another Celestron O-III.

Yep. This is exactly what I needed. Thanks Scanning4Comets!

http://agenaastro.co...m-1-38-exten...

Glad I could be of some help! :jump:

#47 JackeShan

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Posted 21 September 2013 - 06:34 PM

I had to do the same with my 9mm and 14mm ES 100's. In my 10" scope, they won't come to focus unless I pull them out of the focuser about a good 1/2".


Did you ever try the 20mm ES100 in the stock focuser for your Skywatcher? I was very surprised when I could reach focus just as easy as my other eyepieces, without the need to pull the eyepiece out at all to reach focus.






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