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IMPORTANT: Our store is located in Canada. All orders that include products manufactured outside of Canada or USA will be subject to tariffs and duties, regardless of the order value. US customers are responsible for all applicable duties and tariffs, and those will be billed by the carrier, except for the Lacerta upgrade kit, for which we collect them at checkout.
IMPORTANT: Our store is located in Canada. All orders that include products manufactured outside of Canada or USA will be subject to tariffs and duties, regardless of the order value. US customers are responsible for all applicable duties and tariffs, and those will be billed by the carrier, except for the Lacerta upgrade kit, for which we collect them at checkout.
SVBONY SV197 1.25" Cheshire Collimating Eyepiece for Newtonian
SVBONY SV197 Cheshire Collimating Eyepiece - 1.25"
SVBONY SV197 Cheshire Collimating Eyepiece - 1.25"
SVBONY SV197 Cheshire Collimating Eyepiece - 1.25"
SVBONY SV197 Cheshire Collimating Eyepiece - 1.25"
SVBONY SV197 Cheshire Collimating Eyepiece - 1.25"
SVBONY SV197 Cheshire Collimating Eyepiece - 1.25"
SVBONY SV197 1.25" Cheshire Collimating Eyepiece for Newtonian

SVBONY SV197 Cheshire Collimating Eyepiece - 1.25"

by SVBONY
SKU SV-W9154A
$23.97 - $23.97
$23.97
$23.97 - $23.97
$23.97
Price Match Policy!
  • Precise Collimation Tool for Newtonian Telescopes
  • Fits Standard 1.25" Focusers
  • Durable Steel Crosshairs
  • CNC-Machined Aluminum Body
  • Net Weight: 156g (5.51oz)
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  • Description
  • FAQ
  • Specifications
  • In the Box
  • Downloads
  • Warranty

  • SVBONY SV197 1.25" Cheshire Collimating Eyepiece for Newtonian

    The SVBONY SV197 1.25" Cheshire Collimating Eyepiece provides a direct, accurate method for aligning Newtonian reflectors to achieve the sharpest possible views. Its CNC-machined aluminum body weighs a solid 156g and houses durable steel crosshairs, creating a stable and reliable reference point for adjusting your primary and secondary mirrors.

    Precise Newtonian Alignment with a 1.25" Cheshire Eyepiece

    Poor collimation is the single most common reason for soft, low-contrast images in a Newtonian telescope. The SV197 Cheshire eyepiece is a simple, effective tool that gives you a clear view of your mirror alignment, allowing you to make precise adjustments. By fitting directly into any standard 1.25" focuser, it ensures your optical axis is perfectly aligned for optimal image clarity.

    156g CNC-Machined Aluminum Body with Steel Crosshairs

    Built for repeatability and durability, the SV197 features a single-piece aluminum body that is CNC-machined for a precise fit. At 141mm long, it sits securely in the focuser without wobble. Unlike tools with fine wire, the SV197 uses robust steel crosshairs that will not sag, shift, or break, ensuring your alignment reference remains true every time you use it.

    Collimation at f/5 and Slower: A Centered View for Alignment

    This tool is designed to be intuitive, especially for telescopes with focal ratios of f/5 and slower, where the reflections appear centered and straightforward to align. For faster telescopes below f/5, the view through the eyepiece will show a slight, expected offset due to the wider light cone—this is a normal characteristic of Cheshire alignment in fast optics. The goal remains the same: adjust the primary and secondary mirror screws until the reflections are concentric.

  • How does the SVBONY SV197 help collimate my Newtonian telescope?

    The SVBONY SV197 provides a set of crosshairs and a reflective surface that you look through from the focuser. This allows you to see the reflections of your primary and secondary mirrors simultaneously. You then adjust the mirror tilt screws until all the reflections are perfectly centered, ensuring the telescope's optical path is correctly aligned for sharp images.

    Is the SVBONY SV197 Cheshire eyepiece hard to use for a beginner?

    No, it's considered one of the more straightforward collimation tools. Unlike a laser collimator that can itself go out of alignment, a Cheshire is a passive tool that is always accurate. The process involves simple visual checks and adjustments, making it an excellent tool for learning how to properly collimate a Newtonian telescope.

    Will the SV197 work with my 8-inch f/6 Dobsonian?

    Yes, absolutely. An 8-inch f/6 Dobsonian is an ideal telescope for the SVBONY SV197. At f/6, the reflections you see through the Cheshire will be well-centered and easy to align, allowing for a very quick and accurate collimation process.

    Why do the reflections look off-center in my f/4 imaging Newtonian with the SV197?

    This is normal for "fast" telescopes (typically below f/5). The steep light cone of an f/4 optical system requires a slight offset in the secondary mirror's position relative to the primary. The view through the SVBONY SV197 will reflect this, appearing slightly off-center even when perfectly collimated. The tool is still effective, but you must account for this known offset.

    What is the SVBONY SV197 made of?

    The main body of the SV197 is made from CNC-machined aluminum for a precise fit and durability. The internal crosshairs are made of steel, which prevents sagging or breaking over time, ensuring a consistent and reliable alignment reference.

    Can I use the SV197 Cheshire eyepiece with a Schmidt-Cassegrain or refractor?

    No, the SVBONY SV197 is designed specifically for collimating Newtonian reflector telescopes. Refractors and Schmidt-Cassegrains do not have the same user-adjustable secondary and primary mirror configuration and require different tools and procedures for alignment.

  • Barrel Size 1.25" (31.75mm)
    Body Material Aluminum, CNC Machined
    Crosshair Material Steel
    Dimensions 141mm x 41mm x 32mm
    Net Weight 156g / 5.51oz

    • SVBONY SV197 1.25" Cheshire Collimating Eyepiece

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  • SVBONY Warranty Policy