Please see the Specifications tab for sizing details.
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.
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.
How to Use a Bahtinov Mask
First of all, the masks come with 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. The plastic masks will require the user to devise a method of attachment. We suggest masking tape.
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.
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.
|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-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-6018...Fits tube ODs 320 mm to 382 mm
BM-6020...Fits tube ODs 364 mm to 436 mm