Focusing Issue

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KingNothing13 United States of America
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Focusing Issue

#1

Post by KingNothing13 »


I mentioned briefly in my short report about using the Nexus II for the first time a focusing issue with my AD10.

Here's the history:
Up until 2-3 sessions ago there were no problems. My 18mm (2") and 11mm/6.7mm (1.25") all went into the focuser with no issues, focused just fine (with the adaptor for the 1.25").

2-3 sessions ago, I collimated twisting the secondary a bit - the 18mm would not come to focus, even with the focuser at FULL travel. however, when I added in the 35mm extension tube - focused. The 1.25" were fine in the focuser without the extension tube.

Sunday night - I started to need the extension tube for the 1.25" EPs as well.

I have no idea what's going on - does anyone here have any ideas?

I can use the 35mm extension just fine - but I don't understand why all of the sudden this is happening.
-- Brett

Scope: Apertura AD10 with Nexus II with 8192/716000 Step Encoders
EPs: ES 82* 18mm, 11mm, 6.7mm; GSO 30mm
Celestron SkyMaster 15x70 Binoculars
List Counts: Messier: 75; Herschel 400: 30; Caldwell: 12; AL Carbon Star List: 16
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Re: Focusing Issue

#2

Post by KingNothing13 »


I guess it's possible that this COULD be the difference between observing with my contacts (Normal) and Glasses (lately).

My Glasses usually come off, and I have astigmatism on both eyes....Doesn't seem possible, but I guess, as I said, it COULD be.

Hopefully my new contacts come in before my next session, and I can experiment.
-- Brett

Scope: Apertura AD10 with Nexus II with 8192/716000 Step Encoders
EPs: ES 82* 18mm, 11mm, 6.7mm; GSO 30mm
Celestron SkyMaster 15x70 Binoculars
List Counts: Messier: 75; Herschel 400: 30; Caldwell: 12; AL Carbon Star List: 16
Brett's Carbon Star Hunt

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Lady Fraktor Slovakia
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Re: Focusing Issue

#3

Post by Lady Fraktor »


Is the telescope at ambient temperature?
It seems a bit strange it would work and then not.
See Far Sticks: Antares Elita 103/1575, AOM FLT 105/1000, Bresser BV 127/1200, Nočný stopár 152/1200, Vyrobené doma 70/700, Stellarvue NHNG DX 80/552, TAL RS100/1000, Vixen SD115s/885
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Re: Focusing Issue

#4

Post by KingNothing13 »


Lady Fraktor wrote: Wed Sep 02, 2020 5:03 am Is the telescope at ambient temperature?
It seems a bit strange it would work and then not.
Yep. It lives in a shed outside, and when I set it up, I Run the mirror fan for about 45 minutes before observing.

I had it out yesterday after work, so no fan, and it wouldn't focus on the trees some distance away without the 35mm extender.
-- Brett

Scope: Apertura AD10 with Nexus II with 8192/716000 Step Encoders
EPs: ES 82* 18mm, 11mm, 6.7mm; GSO 30mm
Celestron SkyMaster 15x70 Binoculars
List Counts: Messier: 75; Herschel 400: 30; Caldwell: 12; AL Carbon Star List: 16
Brett's Carbon Star Hunt

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Re: Focusing Issue

#5

Post by JayTee »


Maybe do a double check on the collimation adjustments you just made. Maybe put it back to the way it was.

Cheers,
JT
∞ Primary Scopes: #1: Celestron CPC1100 #2: 8" f/7.5 Dob #3: CR150HD f/8 6" frac
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Re: Focusing Issue

#6

Post by KingNothing13 »


Yeah, I was thinking of just "backing" everything out (for lack of a better term) and starting from scratch with the collimation.
-- Brett

Scope: Apertura AD10 with Nexus II with 8192/716000 Step Encoders
EPs: ES 82* 18mm, 11mm, 6.7mm; GSO 30mm
Celestron SkyMaster 15x70 Binoculars
List Counts: Messier: 75; Herschel 400: 30; Caldwell: 12; AL Carbon Star List: 16
Brett's Carbon Star Hunt

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Re: Focusing Issue

#7

Post by Lady Fraktor »


I was just going to suggest pulling everything back as your mirror may be to far forward now.
Hopefully it is something this simple.
See Far Sticks: Antares Elita 103/1575, AOM FLT 105/1000, Bresser BV 127/1200, Nočný stopár 152/1200, Vyrobené doma 70/700, Stellarvue NHNG DX 80/552, TAL RS100/1000, Vixen SD115s/885
EQ: TAL MT-1, Vixen SXP, AXJ, AXD
Az/Alt: AYO Digi II/ Argo Navis, Stellarvue M2C/ Argo Navis
Tripods: Berlebach Planet (2), Uni 28 Astro, Report 372, TAL factory maple, Vixen ASG-CB90, Vixen AXD-TR102
Diagonals: Astro-Physics, Baader Amici, Baader Herschel, iStar Blue, Stellarvue DX, Takahashi prism, TAL, Vixen flip mirror
Eyepieces: Antares to Zeiss
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Re: Focusing Issue

#8

Post by John Baars »


Are those trees nearby? A close by object needs far more outward travel of the focusser than an object at infinity, like a star.
Refractors in frequency of use : *SW Evostar 120ED F/7.5 (all round ), * Vixen 102ED F/9 (vintage), both on Vixen GPDX.
GrabnGo on Alt/AZ : *SW Startravel 102 F/5 refractor( widefield, Sun, push-to), *OMC140 Maksutov F/14.3 ( planets).
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Rijswijk Public Observatory: * Astro-Physics Starfire 130 f/8, * 6 inch Newton, * C9.25, * Meade 14 inch LX600 ACF, *Lunt.
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Re: Focusing Issue

#9

Post by KingNothing13 »


John Baars wrote: Wed Sep 02, 2020 8:11 pm Are those trees nearby? A close by object needs far more outward travel of the focusser than an object at infinity, like a star.
They are *probably* too close - a couple of streets away, but I have been able to focus on them in the past without the extender tube.
-- Brett

Scope: Apertura AD10 with Nexus II with 8192/716000 Step Encoders
EPs: ES 82* 18mm, 11mm, 6.7mm; GSO 30mm
Celestron SkyMaster 15x70 Binoculars
List Counts: Messier: 75; Herschel 400: 30; Caldwell: 12; AL Carbon Star List: 16
Brett's Carbon Star Hunt

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