Collimation Proceedure

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Gulf Coast Guy
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Collimation Proceedure

#1

Post by Gulf Coast Guy »


What does everyone use? This is mine.

https://garyseronik.com/no-tools-telescope-collimation/
Simple and quick. Saves a lot of that Center-Focus- recenter- re-focus... ad nauseum
OTA's: 203mm f10 Meade SCT (LXD75); Antares 80mm Refractor w/William Optics APOGrade f6.9 objective; Orion Starseeker 80 f11.2 Refractor
Mount/tripod's: Meade LXD-75 EQ; Orion Starseeker IV ALT/AZ; Celestron Heavy Duty ALT/AZ Farpoint UBM (Universal Binocular Mount)
Eyepieces:Meade - 26mm plossl, 12mm Astrometric; GSO (OPT badge) 2" Superview 50mm & 30mm 1.25" 15mm; TMB Planetary Series 9mm, 6mm, & 4mm: 10mm & 23mm 60° that came with the 80mm f11.2
Barlows: Orion 2x Shorty; Meade 4000 Series 3x
Binoculars:Brunton 10x50 Celestron Skymaster 15x70 Oberwerk 25x100 IF delux
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John Baars Netherlands
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Re: Collimation Proceedure

#2

Post by John Baars »


Yes, I used this method on my SCT, when I still had one.
Once done, one can repeat it with much higher magnification on a focussed star in order to get a nice concentric first diffraction ring around the Airy disc. Never used a tool.
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).
Most used Eyepieces: *Panoptic 24, *Morpheus 14, *Leica ASPH zoom, *Zeiss barlow, *Pentax XO5.
Commonly used bino's : *Jena 10X50 , * Canon 10X30 IS, *Swarovski Habicht 7X42, * Celestron 15X70, *Kasai 2.3X40
Rijswijk Public Observatory: * Astro-Physics Starfire 130 f/8, * 6 inch Newton, * C9.25, * Meade 14 inch LX600 ACF, *Lunt.
Amateur astronomer since 1970.
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Doug James Canada
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Re: Collimation Proceedure

#3

Post by Doug James »


This is a first for me, and another one of those times that I say to myself, why didn't I think of that.
Celestron Omni XLT 120 Refractor, Orion XT8 Classic Dobsonian - Telrad finder - Sirius Plossl 1.25" eyepieces 40mm,25mm,17mm,
Shorty 2x Barlow lens, Orion Stratus 8mm,13mm,21mm, Baader 36mm, Meade 6.5mm,
Binoculars, Nikon 10x50, Oberwerk 20x80 LW binos
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Re: Collimation Proceedure

#4

Post by stewe »


This is very interesting, it is the first time I read about this method.
My question is: will the possible off-axis aberrations of the eyepiece interfere with the collimation process? Also, how critical is for the collimation that the star arrives at the exact centre of the FOV - do you need a crosshair eyepiece for the procedure?
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JayTee United States of America
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Re: Collimation Proceedure

#5

Post by JayTee »


I use that method for my 6RC but not for my C11. For the C11 I used to use a Duncan mask, but recently my son (in high school shop class) made a new type of Bahtinov focusing mask that can also show whether you are in or out of collimation. Expect a write-up of this new mask soon.

Cheers,
JT
∞ Primary Scopes: #1: Celestron CPC1100 #2: 8" f/7.5 Dob #3: CR150HD f/8 6" frac
∞ AP Scopes: #1: TPO 6" f/9 RC #2: ES 102 f/7 APO #3: ES 80mm f/6 APO
∞ G&G Scopes: #1: Meade 102mm f/7.8 #2: Bresser 102mm f/4.5
∞ Guide Scopes: 70 & 80mm fracs -- The El Cheapo Bros.
∞ Mounts: iOptron CEM70AG, SW EQ6, Celestron AVX, SLT & GT (Alt-Az), Meade DS2000
∞ Cameras: #1: ZWO ASI294MC Pro #2: 662MC #3: 120MC, Canon T3i, Orion SSAG, WYZE Cam3
∞ Binos: 10X50,11X70,15X70, 25X100
∞ EPs: ES 2": 21mm 100° & 30mm 82° Pentax XW: 7, 10, 14, & 20mm 70°

Searching the skies since 1966. "I never met a scope I didn't want to keep."

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Re: Collimation Proceedure

#6

Post by stewe »


I recently bought a Duncan mask from Morris Engraving:
https://www.ebay.de/usr/morris-engravin ... 2749.l2754
I know that many people use DIY Duncan masks, but I bought this one because it is a precision-cut mask with a nice matte black finish, so I thought the little extra spending was going to be worth it. I glued three tiny plastic handles onto one side of the mask in order to avoid touching the corrector plate with my finger when applying the mask.

This mask is extremely lightweight and fits perfectly on my C9.25. I had the opportunity to try it out for the first time yesterday night because I found that my SCT was slightly out of collimation.
Seeing was not very good with lots of intermittency. Nevertheless, I managed to collimate the scope with the mask much more easily than using the concentric rings of a defocused star. With the mask, it is very easy to find out which screws to adjust. I am sure that with better seeing, collimation with the mask will be a breeze.
I think SCT manufacturers like Celestron should be selling their telescopes with this mask.
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Piet Le Roux South Africa
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Re: Collimation Proceedure

#7

Post by Piet Le Roux »


As far as SCT's go I don't know any other way to do it except I use a wooden stick, something like a chopstick, that I hold from the centre of the secondary mirror and point the other end towards the direction where the darker shadow is offset in the ring of light or towards the part where of the rings are the thinnest. While holding the stick move to the front and check towards which of the three screws it's pointing, that's the screw you must adjust. If it points in between two screws adjust the one on the opposite side. Move the scope so that the thin side of the ring is close to the edge of view, you must then turn the screw so that the rings move towards the centre of view, if it moves out of view, reverse the direction. If the SCT is bigger than 8" get a friend to help.
Main Equipment : Tele Vue 27mm Panoptic, 7&13mm Nagler, Big Barlow : 8" Meade LX90ACF with Meade 2.0" Enhanced Diagonal : Camera Fuji XT100
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