Celestron 1.25" Cheshire Collimating Eyepiece for Newtonian Reflectors
Ships by Next Business Day
Contiguous US Customers:
All items we sell ship for free within the Contiguous US. Shipping will be via the cheapest shipping method which will vary depending on the items in your order. During checkout, you may also be shown other optional faster shipping choices.
US Customers in Hawaii and Alaska:
Free shipping applies to almost all products. A few large telescopes and mounts are excluded from this free shipping offer. For these items, please contact us to obtain a shipping quote before you check out using the online shopping cart.
International Customers:
Free shipping does not apply to international orders. During check-out, you will be presented with several shipping choices and costs. However, the export of some items may be restricted outside the US due to size or manufacturer restrictions.
The Celestron Cheshire Collimation Eyepiece is ideal for precise collimation of Newtonians and helpful for aligning Schmidt-Cassegrains. This special eyepiece fits into 1.25" focusers or diagonals.
Alignment is easy using the small opening on one end and thin cross hairs at the other end. The collimation eyepiece is more accurate than the simple Collimation Tool.
Item weighs 5.2oz. Total length is approx. 143mm / 5.64". Insertion length is 102mm / 4.02". Please see schematic diagram in photo 3 above for detailed measurements.
Given the dimensions of this Cheshire, it’s possible to sight the full aperture of the primary and secondary of a Newtonian with a focal ratio of approximately f/5 and slower. With faster scopes, it may be necessary to pull the Cheshire out of the focuser somewhat to see the outer edge of the secondary and adjust it so it’s in the center of the field. This adjustment is usually required if the secondary is removed from the tube and replaced, or if it was badly positioned at the factory. When the Cheshire is pulled out slightly, it may be difficult to see the edge of the primary, but if the primary has an accurately placed center dot, alignment remains straightforward. For example, we’ve used this Cheshire to quickly collimate Newtonians with a focal ratio of f/4.7. For scopes with focal ratios of f/4.5 or faster, a shorter Cheshire or sighting tube (or a laser collimator) may be required because of the large secondary.
Product carries full 2 year Celestron factory limited warranty (within US/Canada only).
| Free Shipping Graphic | Free US Shipping |
|---|---|
| Hide Found a better Shipped Price on Frontend? | No |
The Celestron Cheshire Collimation Eyepiece is ideal for precise collimation of Newtonians and helpful for aligning Schmidt-Cassegrains. This special eyepiece fits into 1.25" focusers or diagonals.
Alignment is easy using the small opening on one end and thin cross hairs at the other end. The collimation eyepiece is more accurate than the simple Collimation Tool.
Item weighs 5.2oz. Total length is approx. 143mm / 5.64". Insertion length is 102mm / 4.02". Please see schematic diagram in photo 3 above for detailed measurements.
Given the dimensions of this Cheshire, it’s possible to sight the full aperture of the primary and secondary of a Newtonian with a focal ratio of approximately f/5 and slower. With faster scopes, it may be necessary to pull the Cheshire out of the focuser somewhat to see the outer edge of the secondary and adjust it so it’s in the center of the field. This adjustment is usually required if the secondary is removed from the tube and replaced, or if it was badly positioned at the factory. When the Cheshire is pulled out slightly, it may be difficult to see the edge of the primary, but if the primary has an accurately placed center dot, alignment remains straightforward. For example, we’ve used this Cheshire to quickly collimate Newtonians with a focal ratio of f/4.7. For scopes with focal ratios of f/4.5 or faster, a shorter Cheshire or sighting tube (or a laser collimator) may be required because of the large secondary.
Product carries full 2 year Celestron factory limited warranty (within US/Canada only).
| Free Shipping Graphic | Free US Shipping |
|---|---|
| Hide Found a better Shipped Price on Frontend? | No |
Celestron 1.25" Cheshire Collimating Eyepiece for Newtonian Reflectors # 94182