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#1 ArtVandelay

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Posted 21 August 2013 - 11:44 AM

I received my new ES 100 degree 9mm EP today. This is my first real EP addition to my Orion Skyview 8 Pro set up. I put it in the scope and looked at some trees in the distance. There was not much else to look at during the day. I was unable to focus on them as the draw tube hit its outer limit. Now I know that for terrestrial use a lot of larger EP's need a tube extender. I just wanted a quick glance through the EP that costs almost as much as my OTA. So my big question is will I need an extender for normal deep sky viewing? I have about 8 hours left until night, and want to order one today if I will end up needing one. I just thought that I would ask the Experts. I am sure that someone here uses this EP in the same Newt as I do. Thanks!

#2 McUH

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Posted 21 August 2013 - 12:27 PM

I'm no expert but it probably depends on how far the trees are. If they are really distant and you can't focus on them, then you most likely won't be able to focus to infinity at night too.

#3 SteveG

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Posted 21 August 2013 - 12:40 PM

Try pulling the eyepiece out of the focuser a little bit, then be sure to clamp it down tightly. At night, you're going to enjoy that 100 deg eyepiece. I would have recommended the 14 first, but the 9 should be great.

#4 csrlice12

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Posted 21 August 2013 - 01:00 PM

My nine still isn't in yet. +1on the 14mm. Still trying out the 20, but so far, it's a great one too.

#5 ArtVandelay

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Posted 21 August 2013 - 01:12 PM

The 14 is back ordered. As soon as they have more in stock they will send it.

#6 Scanning4Comets

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Posted 21 August 2013 - 01:32 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".

For both eyepieces, I added O-Rings so they can now reach focus. I also had to add 2 empty 2 inch filter cells to my 9mm ES 100, so that the barrel is longer and sits better in the focuser. I would have used a 14mm Baader fine tuning ring, but the one I have is too long at 28mm, so the 2" empty filter cells sufficed.

See attachments. I hope this helps!

Attached Files



#7 Scanning4Comets

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Posted 21 August 2013 - 01:34 PM

..

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#8 Mike B

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Posted 21 August 2013 - 01:39 PM

Try pulling the eyepiece out of the focuser a little bit...

Yes, even if you have to hold it in your hand while doing-- just to make double-dog certain it is truly OUT focus you are needing! If it turns out to be *IN* focus you're short on, then you have a whole new problem...

As an alternative thot, assuming you *do* need a 2" extension, perhaps a good 2" Barlow having the lens cell removable (threaded-on) might come in handy?.... so the Barlow's tube can be used, sans-optics, as the "extension".
:grin:

#9 MingoT

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Posted 21 August 2013 - 02:12 PM

On my orion xt12i, moving down the primary mirror with the colimation screws was just enough to achieve focus on the stars.
Cheers,
Mingo

#10 Starman1

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Posted 21 August 2013 - 02:59 PM

Try pulling the eyepiece out of the focuser a little bit...

Yes, even if you have to hold it in your hand while doing-- just to make double-dog certain it is truly OUT focus you are needing! If it turns out to be *IN* focus you're short on, then you have a whole new problem...

As an alternative thot, assuming you *do* need a 2" extension, perhaps a good 2" Barlow having the lens cell removable (threaded-on) might come in handy?.... so the Barlow's tube can be used, sans-optics, as the "extension".
:grin:

That's called "killing two birds with one stone". You get a good barlow to use AND an extension tube. :waytogo:
However, any extension tube will pull a 2" eyepiece back by the FULL length of the barrel. You may not want to pull an eyepiece back 2" or more, because now you'll have to move your focuser in a similar amount to achieve focus, and running out of in-travel is a harder-to-fix problem.
I would first try adding barrel extenders to the eyepieces because they would allow you to pull the eyepiece back, say, 1/2" and still be secure in the focuser.

#11 Mike B

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Posted 21 August 2013 - 03:17 PM

Yeah, like Markus' solution depicted a few posts above!

I have such a thread-on extender, and it works quite well. Don, do you have a collection of these at your shop?

#12 Pollux556

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Posted 21 August 2013 - 05:13 PM


For both eyepieces, I added O-Rings so they can now reach focus. I also had to add 2 empty 2 inch filter cells to my 9mm ES 100, so that the barrel is longer and sits better in the focuser. I would have used a 14mm Baader fine tuning ring, but the one I have is too long at 28mm, so the 2" empty filter cells sufficed.

See attachments. I hope this helps!


Hum, the margin of safety seems greatly reduced, is it not ?

#13 Scanning4Comets

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Posted 21 August 2013 - 05:44 PM

How so?

Both barrels have plenty of space on them and I use compression rings on my 2" focuser. Hardly a "margin of safety". Good part about them also is that they won't "hang up" in the focuser on the tapered part...mine are no longer tapered and I am very careful when I use my eyepieces and ALWAYS clamp those suckers down with the compression ring on the focuser.

Not clamping them down in the compression ring is just asking for trouble !!!

The margin of safety is only reduced if you are careless!

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#14 Mike B

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Posted 21 August 2013 - 07:41 PM

The margin of safety is only reduced if you are careless!

Say- aren't you the bloke with the flying 9mm howitzer eyepiece? :smirk:

#15 Rick Woods

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Posted 21 August 2013 - 08:09 PM

Try pulling the eyepiece out of the focuser a little bit...

Yes, even if you have to hold it in your hand while doing-- just to make double-dog certain it is truly OUT focus you are needing! If it turns out to be *IN* focus you're short on, then you have a whole new problem...

As an alternative thot, assuming you *do* need a 2" extension, perhaps a good 2" Barlow having the lens cell removable (threaded-on) might come in handy?.... so the Barlow's tube can be used, sans-optics, as the "extension".
:grin:


Another thought is to cut a ring of 2" ID (inside diameter) PVC pipe, slip it over the barrel, and use that for your spacer. I made a few of these so my 40mm Wide Field, 20mm Nagler (T2), and 14mm Meade UWA would be parfocal. I stopped using them when I started using a big SCT, but they worked well for a long time.

#16 ArtVandelay

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Posted 21 August 2013 - 09:03 PM

Well, it got dark enough to go outside and give it a try. Looks like pulling out the EP about 1/3 of an inch brought everything into focus. I plan to get an extension tube now. It didn't even occur to me when ordering that I may need one. The one from Orion just has two set screws. Does anyone know what the cheapest option is that uses a compression ring? I am headed out on a 12 hour drive to the middle of know where upper peninsula Michigan with dark skies on Sunday. I know that anything I order will not get here by then unless I pay twice the value in shipping. I checked Amazon and they don't have anything available on Prime shipping that would get to me Friday. So I guess for now I will use the pull out method while up there!

#17 Pollux556

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Posted 21 August 2013 - 09:25 PM

The margin of safety is only reduced if you are careless!

Say- aren't you the bloke with the flying 9mm howitzer eyepiece? :smirk:


:funny:

He knows it better than anyone.

#18 Scanning4Comets

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Posted 21 August 2013 - 09:58 PM

Say- aren't you the bloke with the flying 9mm howitzer eyepiece?


Actually, it was a 14mm ES 100 that went flying out of a telescope. :roflmao: I lent it out and it was put into a refractor. The person who borrowed it didn't tighten the eyepiece in the diagonal and didn't tighten each axis of his scope. This resulted in the objective end of the scope to tip downwards and the eyepiece upwards launching it in the air and to the ground below.

Nothing could have saved the eyepiece except for clamping everything down....So, it doesn't matter how deep or shallow the eyepiece was sitting in the diagonal.

Hum, the margin of safety seems greatly reduced, is it not ?


The above quote does not apply here at all.

#19 kkokkolis

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Posted 22 August 2013 - 06:57 AM

I use a Baader HYPERION FINETUNING STOP RING 2", this one, with or without fine tune rings, but not for ES100s, usually for Nagler T4 12mm that can't focus as 2" on certain telescopes.
I like the O ring solution. Usually my 50mm O Rings (from 50mm finders) are lost, so I'm always short of them. Markus has many!

#20 Pollux556

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Posted 22 August 2013 - 08:12 AM


Hum, the margin of safety seems greatly reduced, is it not ?


The above quote does not apply here at all.


I can delete my post if you want. :ubetcha:

#21 Scanning4Comets

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Posted 22 August 2013 - 10:10 AM

Nah, it's ok, it's all good :ubetcha: No harm was intended by you. :cool:

#22 Pollux556

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Posted 22 August 2013 - 10:12 AM

No problem Markus. Hey, I have exactly the ES setup as you.

30mm ES 82°, 14mm ES 100°, 9mm ES 100°

#23 Scanning4Comets

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Posted 22 August 2013 - 10:41 AM

Nice! Aren't you also a collector of vintage eyepieces too?

Cheers,

#24 Pollux556

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Posted 22 August 2013 - 11:23 AM

Nice! Aren't you also a collector of vintage eyepieces too?

Cheers,


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 ?

#25 csrlice12

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Posted 22 August 2013 - 11:56 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.






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