Kendrick Astro Bahtinov Focus Masks (BMC-60)
Kendrick Astro Bahtinov Focus Masks (BMC-60)
Bahtinov Mask Option (See Specifications)
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Product Description
Kendrick Bahtinov Focus Masks
ALL NEW DESIGN - Now Clear Transparent This innovative focus mask concept was invented by a Russian amatuer astronomer, Paul Bahtinov, and Kendrick is producing these masks with his permission.
The Bahtinov mask allows digital astrophotographers and visual observers to get razor sharp focus in seconds!
The difference in focuser position between the four pictures shown below is very small, a few tenths of a mm. The method is very fast and incredibly sensitive. There is no guessing when you are focused during times of poor to moderate seeing. Simply put the mask and the status of your focus will become immediately apparent.
The masks have a series of slots that create a unique diffraction pattern that can be used to quickly bring your telescope to focus with an absolute minimum of fuss.
Astro Photography Tool (APT)
We are happy to provide a link to an excellent astrophotography tool called APT (Astro Photography Tool) www.astroplace.net. APT has a function called Bahtinov Aid based on Bahtinov Grabber technology and it provides an excellent visual and digital reference when using a Bahtinov mask to come to focus. We do not sell or provide support for APT.
How to Use a Bahtinov Mask
The masks use three adjustable rubber bumpers. This allows them to fit to a wide variety of tube diameters. Simply push the bumper to the desired location on the slot to ensure that the mask is properly centered over your optic. Then focus. The graphic below describes visually what you will see on either side of being focused. This graphic represents movement of the focuser in very small amounts (fractions of a mm). It is extremely sensitive.
Note: There are three ways to use the bumpers on our masks to achieve a proper fit to your telescope:
- Bumpers can be adjusted to fit “outside” of the tube or dewcap.
- Bumpers can be adjusted to fit “inside” the tube or dewcap.
- If fit cannot be achieved using the two methods above, flip the mask over to use the smaller bumper footprint on the flip side.
The Bahtinov Mask is probably the easiest product on the market to achieve tight focus for visual use and for digital astrophotographers, regardless of whether you use a DSLR or CCD camera.
What's in the Box
Specifications
Tube Diameter Fitting Dimensions:
| Bahtinov Mask SKU | Min. Tube OD | Max. Tube OD | Intended Usage |
| BMC-6001-GS | 56 mm | 92 mm | for 50mm Guide scope |
| BMC-6001-CM | 64 mm | 100 mm | for 60mm Scopes and Camera Lenses w/ a 60mm Diameter Optic |
| BMC-6002-CM | 77 mm | 108 mm | for Cameral Lens with 67mm Diameter Optic |
| BMC-6003-CM | 82 mm | 120 mm | for Cameral Lens with 77mm Diameter Optic |
| BMC-6004 | 86 mm | 148 mm | for 80 mm Optic |
| BMC-6006 | 114 mm | 166 mm | for 90 to 105 mm Optic |
| BMC-6007 | 120 mm | 180 mm | for 105mm to 115 mm Optic |
| BMC-6008-SC | 133 mm | 184 mm | for 115mm to 125 mm Optic (for C5 SCTs & Mak Cassegrains) |
| BMC-6008 | 128 mm | 190 mm | for 120 mm to 130 mm Optic |
| BMC-6011 | 164 mm | 226 mm | for 150 mm to 165 mm Optic |
| BMC-6013 | 208 mm | 270 mm | for 8" SCT |
| BMC-6013-R | 208 mm | 270 mm | for 8" Rowe-Ackermann Schmidt Astrograph |
| BMC-6015 | 250 mm | 312 mm | for Celestron C9.25 SCT |
| BMC-6016 | 264 mm | 336 mm | for Meade 10" SCT |
| BMC-6017 | 294 mm | 356 mm | for Celestron C11 SCT |
| BMC-6018 | 320 mm | 382 mm | for Meade 12" SCT |
| BMC-6020 | 364 mm | 436 mm | for Celestron C14 and Meade 14" |
