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N10 for Visual Observations


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#1 DaveK

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Posted 08 July 2013 - 10:18 PM

Has anyone used their N10 for visual observations?

 

When I purchased my N10 almost two years ago I never imagined that I would use my N10 astrograph for visual use but finally the time has come where I need to do it.

 

Unfortunately, my preliminary tests are poor due to focusing issues with the OK3 focuser.

 

The N10 came with an adapater that screws into the OK3 focuser and provides a brass compression ring. I tried using a TeleVue diagonal and a few TeleVue 2 inch eyepieces but I am not able to rack the focuser in far enough to achieve focus.

 

Then I tried using an eyepiece directly into the adapter and couldn't rack the focuser out far enough. I then added both a 1 inch and a 2 inch extension and still could rack the focuser out far enough. I then found a 4 inch extension and that put focus out too far and like the diagonal I couldn't rach the focuser in far enough.

 

Sure, I realize the simple solutions here are to either get a 3" extension or don't use the N10 for visual use, but I really need to find a solution.

 

I am hosting a star party here in Arizona to raise money for the 19 local firefighters that died fighting wildfires near my home and I need every telescope I have to be available for viewing. While the 3" extension might solve my issue, it is very uncomfortable to use a direct insertion of the eyepieces. A diagonal is really preferred to position the eyepiece in a reasonable direction.

 

Has anyone used their N10 for visual use? How can I use this telescope with a diagonal so that I can position the eyepiece into a comfortable place for my guests?


Edited by DaveK, 08 July 2013 - 10:19 PM.


#2 w0mbat

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Posted 09 July 2013 - 05:04 AM

Hi Dave,

Interesting question. I recently took delivery of my new N10. After I ordered it, it occurred to me to ask the same question of ASA through my ASA agent in Australia. The short reply I got from my agent was that "they (ASA) were not keen on the idea". Unfortunately that is all I was told so I don't know their reasons. I ended up buying a 102mm refractor for visual use which I eventually intend to mount on top of the N10 tube rings.

Ian


ASA DDM60Pro, ASA N10 Astrograph, Orion ED102T CF Refractor, Canon 60Da DSLR, Sirius 2.3 Metre Observatory, WIN10 Pro 64bit.


#3 MarkS

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Posted 11 July 2013 - 03:12 PM

Hi Dave and Ian,

 

I have a 10N, and family issues dictate that I make it available for visuals(!)

 

I have no quick fix but what I have done is make an adapter for 1.25" eyepiece to the Wynne Corrector. If I've done my sums properly, it should provide decent viewing.

 

I'll report as soon as I have tested the set-up.

 

Mark



#4 DaveK

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Posted 11 July 2013 - 05:22 PM

Mark,

 

I look forward to learning about your results. Unfortuantely, my event is tomorrow night (weather permitting) and I am out of time to find a solution. I guess ASA isn't monitoring their own threads any better than they monitored the Yahoo group. Oh well, I know they are busy making products. Hopefully one day they will dedicate a person to helping people on thier forum.

 

The biggest issue for me is the fact that I cannot use a diagonal. Using any eyepiece without a diagonal will likely place the viewer in some very uncomfortable positions.

 

Best of luck with your tests.



#5 MarkS

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Posted 12 July 2013 - 12:28 AM

Mark,

 

I look forward to learning about your results. Unfortuantely, my event is tomorrow night (weather permitting) and I am out of time to find a solution. I guess ASA isn't monitoring their own threads any better than they monitored the Yahoo group. Oh well, I know they are busy making products. Hopefully one day they will dedicate a person to helping people on thier forum.

 

The biggest issue for me is the fact that I cannot use a diagonal. Using any eyepiece without a diagonal will likely place the viewer in some very uncomfortable positions.

 

Best of luck with your tests.

I will certainly be unable to use a diagonal: there is not enough back focus distance. But any target above ~60 degrees altitude should be OK for viewing comfort. The only really bad areas would be close to the meridian in the south (southern hemisphere location).

 

Again. time will tell!

 

Mark



#6 MarkS

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Posted 28 August 2013 - 11:49 PM

I promised I would report back on using a 10N visually, so here goes. After a run of rotten weather I at last got the 10N under the stars with an eyepiece!

 

I made up an adapter to go between the 3" Wynne and 1.25" eyepiece with a 57mm face to face distance. I used a Pentax 7mm eyepiece. The OK3 found focus at ~10 - 11mm. I don't know if that backfocus is ideal, but it must be close.

 

Unfortunately I couldn't get to my dark sky site, so I had to be content with heavy light pollution and some cloud interruption.

 

As I expected, very bright objects had big diffraction spikes, but the view on fainter ones was excellent. As long as I didn't look at objects below about 50 degrees altitude, viewing wasn't too uncomfortable.

 

I also tried a 3.5mm eyepiece to split some doubles, and it seemed fine, but I was cut short by clouds.

 

The resolution on objects such as NGC 5139, NGC 104 and NGC6752 was excellent - even with all the excess ambient light. And NGC4755 looked gorgeous, with the different star colours showing nicely.

 

So now I must try it under dark skies to see this set-up at its best.



#7 w0mbat

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Posted 24 December 2013 - 11:01 PM

Hi Mark,

Inspired by your success I have recently had an eyepiece adapter machined for my N10. Unfortunately I appear to have made some sort of error as I cannot achieve focus. The adapter I have has a "face to face" length of 57mm as you suggested. I interpreted this as the distance from the mounting flange on the 3" Wynne corrector to the other end on which the eyepiece rests when fully inserted. So far (yesterday, in amongst the usual Christmas activity) I have only tried a Baader Hyperion zoom eyepiece. If I pull out the eyepiece from the holder until it is nearly falling out focus is nearly reached with the OK3 fully out. Unfortunately my optical knowledge is insufficient to understand where I have gone wrong. I had the adapter made for the visit of my family over Christmas so this is all a bit disappointing! Any advice you (or others) could give would be greatly appreciated.

Regards and Christmas greetings to all,

Ian


ASA DDM60Pro, ASA N10 Astrograph, Orion ED102T CF Refractor, Canon 60Da DSLR, Sirius 2.3 Metre Observatory, WIN10 Pro 64bit.


#8 w0mbat

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Posted 03 January 2014 - 09:10 AM

Hi again,

Please ignore previous post. I was testing during daylight and chose an object to focus on which was way too close! A silly mistake!

Ian


ASA DDM60Pro, ASA N10 Astrograph, Orion ED102T CF Refractor, Canon 60Da DSLR, Sirius 2.3 Metre Observatory, WIN10 Pro 64bit.


#9 MarkS

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Posted 04 February 2014 - 08:00 AM

Hi Ian,

 

Glad to hear it was OK - it's an easy trap. A 'long distance away' ain't infinity!

 

With the 57 mm stand-off the focus point using the Pentax eyepieces was within a mm or so of the photo focus point,  which seemed fine.

 

Regards,

Mark






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