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Kendrick Bahtnov Focus Masks

Bahtnov masks are offered in two styles, rigid masks and flexible plastic film masks. The rigid masks will not bend whereas the plastic film masks are rollable and extremely lightweight.

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.

 
Flexible Thin Film Bahtinov Masks
These flexible plastic masks are constructed of an opaque black plastic film that is very tough yet very flexible. When rolled up and released, it will revert back to its natural flat state. This makes for very easy storage as they will fit easily into many accessory cases once rolled up.

They come with three tabs exactly the same as our rigid plastic masks but unlike the rigid masks, we do not provide rubber bumpers with them. The tabs can be used as an aid in connecting the mask to your telescope per a method of your choice. If the tabs are deemed undesirable, they can be trimmed off with a pair of scissors. Also, the flexible masks can be glued into one of our R-60 Aluminum Rings if you prefer a more rigid, but still lightweight, set up. A list of rings to fit the various plastic masks is provided below in the technical spec section.

 
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
First of all, the rigid 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.


Above are examples of our Flexible Thin Film Bahtinov Masks. Extremely lightweight, portable, tough, precision laser cut and rollable. No memory, roll out flat. The tabs can be easily trimmed off to allow for insertion into our R-60 Aluminum Rings if you wish

 
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-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

Rigid Bahtinov Masks

SKUDescriptionPrice 
BM-6001-GS Bahtinov Mask for 50mm Guide scope CAN $17.00
BM-6001-CM Bahtinov Focusing mask for 60mm Scopes and cameral lenses with a 60mm diameter optic CAN $17.00
BM-6002-CM Bahtinov Focusing mask for cameral lens with 67mm diameter optic CAN $17.00
BM-6003-CM Bahtinov Focusing mask for cameral lens with 77mm diameter optic CAN $17.00
BM-6004 Bahtinov Focusing mask for 80 mm optic CAN $22.00
BM-6006 Bahtinov Focusing mask for 90 to 105 mm optic CAN $26.00
BM-6007 Bahtinov Focusing mask for 105mm to 115 mm optic CAN $28.00
BM-6008 Bahtinov Focusing mask for 120 mm to 130 mm optic CAN $34.00
BM-6008-SC Bahtinov Focusing mask for 115mm to 125 mm optic (For C5 SCTs & Mak Cassegrains) CAN $28.00
BM-6011 Bahtinov Focusing mask for 150 mm to 165 mm optic CAN $39.00
BM-6013 Bahtinov Focusing mask for 8" SCT CAN $50.00
BM-6015 Bahtinov Focusing mask for Celestron C9.25 SCT CAN $62.00
BM-6016 Bahtinov Focusing mask for Meade: 10" SCT CAN $78.00
BM-6017 Bahtinov Focusing mask for Celestron C11 SCT CAN $90.00
BM-6018 Bahtinov Focusing mask for Meade 12" SCT CAN $95.00
BM-6020 Bahtinov Focusing mask for Celestron C14 and Meade 14 CAN $101.00

 

Flexible Bahtinov Masks

SKUDescriptionPrice 
BM-6006-P Flexible Plastic Bahtinov Focusing mask for 90 to 105 mm optic CAN $14.00
BM-6007-P Flexible Plastic Bahtinov Focusing mask for 105 mm to 115 mm optic CAN $17.00
BM-6008-P Flexible Plastic Bahtinov Focusing mask for 120 mm to 130 mm optic CAN $17.00
BM-6017-P Flexible Plastic Bahtinov Focusing mask for Celestron C11 SCT CAN $34.00

 

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