3D Astro Bahtinov Focus Mask - 80mm ID
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.
Bahtinov mask to aid in focusing your Askar 40mm Guidescope # FMA180. Will also work for similar scopes which have a dewshield outside diameter of 52mm (check your guidescope before purchase if you are not sure).
We're not sure how necessary or effective this might be on a small-aperture guidescope, but several people have expressed interest in this item, so here it is.
With the mask on, you can see a diffraction spike pattern. Focus until you achieve a symetrical pattern. Once the best focus has been achieved, you can remove the mask and use the guide scope as normal.
This mask is deliberately designed to fit loosely over the guidescope dewshield so that it can be removed very easily when focusing is accomplished. It does not have a firm fit like an end cap would so that the imaging setup isn’t disturbed when you take this off.
3D printed from PLA.
Color of current stock is silver-gray but is subject to change without notice.
| Product Banner Type | new |
|---|---|
| Free Shipping Graphic | Free US Shipping |
| Hide Found a better Shipped Price on Frontend? | No |
Bahtinov mask to aid in focusing your Askar 40mm Guidescope # FMA180. Will also work for similar scopes which have a dewshield outside diameter of 52mm (check your guidescope before purchase if you are not sure).
We're not sure how necessary or effective this might be on a small-aperture guidescope, but several people have expressed interest in this item, so here it is.
With the mask on, you can see a diffraction spike pattern. Focus until you achieve a symetrical pattern. Once the best focus has been achieved, you can remove the mask and use the guide scope as normal.
This mask is deliberately designed to fit loosely over the guidescope dewshield so that it can be removed very easily when focusing is accomplished. It does not have a firm fit like an end cap would so that the imaging setup isn’t disturbed when you take this off.
3D printed from PLA.
Color of current stock is silver-gray but is subject to change without notice.
| Product Banner Type | new |
|---|---|
| Free Shipping Graphic | Free US Shipping |
| Hide Found a better Shipped Price on Frontend? | No |
3D Astro Bahtinov Focus Mask - 80mm ID # BM-S-80