Kendrick Astro Bahtinov Focus Opaque Masks (BM-60)
Kendrick Astro Bahtinov Focus Opaque Masks (BM-60)
Bahtinov Mask Option (See Specifications) - BM-6001-GS 56-92mm
$37 BM-6001-CM 64-100mm
$37 BM-6002-CM 77-108mm
$37 BM-6003-CM 82-120mm
$37 BM-6004 86-148mm
$37 BM-6006 114-166mm
$39 BM-6007 120-180mm
$41 BM-6008-SC 133-184mm
$41 BM-6008 128-190mm
$41 BM-6011 164-226mm
$55 BM-6013 208-270mm
$71 BM-6013-R RASA 208-270mm
$71 BM-6015 250-312mm
$87 BM-6016 264-336mm
$110 BM-6017 294-356mm
$127 BM-6018 320-382mm
$134 BM-6020 364-436mm
$142
Why Purchase from All-Star Telescope?
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Product Description
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.
Rigid Bahtinov Mask
Above is an example of our Rigid Bahtinov Masks. Lightweight, precision CNC cut, non flexing and with adjustable rubber tabs to get a quick and easy fit.
Bahtinov Grabber from APT
Click on this tumbnail for a larger image of the Bahtinov Grabber from 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.
How To Video
This short YouTube video will show you how to choose the right size and how to use the mask under the stars https://youtu.be/5xiYQMkd7wE.
What's in the Box
Specifications
Technical Specifications for the Rigid Masks:
| Material: | Plastic | |
| Finished Colour: | Black | |
| Weight: | ||
| BM-6004...10 grams, .3 oz BM-6006...26 grams, .9 oz BM-6007...22 grams, .7 oz BM-6008...26 grams, .9 oz |
BM-6011...56 grams, 1.9 oz BM-6013...50 grams, 1.8 oz BM-6015...120 grams, 4.2 oz BM-6016...142 grams, 5 oz |
BM-6017...82 grams, 2.9 oz BM-6018...102 grams, 3.6 oz BM-6020...250 grams, 8.9 oz |
| Tube (not optical) Diameter Fitting Dimensions: | ||
| BM-6001-GS...Fits tube ODs 56 mm to 92 mm BM-6001-CM...Fits tube ODs 64 mm to 100 mm BM-6002-CM...Fits tube ODs 77 mm to 108 mm BM-6003-CM...Fits tube ODs 82 mm to 120 mm BM-6004...Fits tube ODs 86 mm to 148 mm BM-6006...Fits tube ODs 114 mm to 166 mm BM-6007...Fits tube ODs 120 mm to 180 mm |
BM-6008-SC...Fits tube ODs 133 mm to 184 mm BM-6008...Fits tube ODs 128 mm to 190 mm BM-6011...Fits tube ODs 164 mm to 226 mm BM-6013...Fits tube ODs 208 mm to 270 mm BM-6016-R...Celestron 8" Rowe-Ackermann Schmidt Astrograph BM-6015...Fits tube ODs 250 mm to 312 mm |
BM-6016...Fits tube ODs 264 mm to 336 mm BM-6017...Fits tube ODs 294 mm to 356 mm BM-6017-R...Celestron 11" Rowe-Ackermann Schmidt Astrograph BM-6018...Fits tube ODs 320 mm to 382 mm BM-6020...Fits tube ODs 364 mm to 436 mm |
