Skylabs Cheshire Eyepiece
The collimation (alignment) of a telescope's mirrors is extremely important for visual observation. For very fast visual telescopes (focal ratio < 5) and telescopes used for astrophotography, collimation becomes critical.
Traditional Cheshire eyepieces are quite subjective, making collimation a challenge, as they cannot achieve the precision required for astrophotography or relatively fast telescopes.
The innovative Skylabs Cheshire Eyepiece enables the precise alignment of the optical axes of the primary and secondary mirrors in Schmidt-Newtonian, Maksutov-Newtonian, and Newtonian telescopes with unprecedented accuracy.
How to Use a Cheshire Eyepiece
How does it work?
The reflective Cheshire eyepiece relies on a perfectly centered reflective spot on the Newtonian telescope's primary mirror and a reflective circle at the eyepiece's edge. The circle's image reflects multiple times between the telescope's mirrors, enabling exceptionally precise and objective collimation.
Single-beam laser collimators are affordable and user-friendly but cannot correct the secondary mirror's off-axis position or verify both mirrors' alignment. While lasers expedite the process, a Cheshire eyepiece remains essential for achieving perfect mirror collimation.
Most Newtonian telescopes feature a center-marked donut or triangle on the primary mirror. If yours lacks one, Skylabs' mirror spotting template and center spots are crucial. Select the correct size: the small triangle for 1.25" Cheshires or the larger one for 2" models. A 2" Cheshire is strongly recommended if your focuser is 2".
Documentation and FAQs
Documentation
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Skylabs Cheshire Eyepiece documentation PDF [145kb].
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How to Achieve Accurate Collimation of Newtonian Telescopes - official blog.
FAQs
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Can I use it at night?
Yes, shine a flashlight at the cutout. -
Can it align a Schmidt-Cassegrain?
No, it is meant for Newtonian reflectors. -
Do I need batteries for it?
No, it uses ambient light. -
Where should I store this product?
Please keep this product with the rest of your sensitive photography and astronomy equipment, protected from humidity and high temperatures. Storage temperature range: -10°C to 45°C (14°F to 113°F).