Current Price: $29.99
Buy It Now Price: $29.99
Bids: 0

Astromania Bahtinov Mask Focusing Mask for Telescopes - FM200mm for a tube outer diameter (OD) from 215mm-260mm - can be mounted with the brass screws inside or outside the drawtube

Description

Size:For Outer Diameter from 215mm-260mm The Bahtinov mask has become the
preferred method of focusing a telescope, either visually or when imaging with
a CCD camera, DSLR or webcam.They are an inexpensive tool which will allow you
to achieve pin-sharp levels of focus, saving you time and improving your work.
Simply place the mask over the front of your ‘scope, align the scope towards a
star. The mask displays a unique diffraction profile; one part of the
diffraction pattern moves in response to changes in focus and displays error
as a displacement from a clearly defined point.Whether you’re doing planetary
visual observing, planetary imaging,or deep sky imaging, the Bahtinov Mask is
a great accessory to get the best focus for your telescope quickly and
easily.These high quality Bahtinov masks are adjustable to fit a wide range of
optical tubes, unlike masks which are only able to fit one telescope.The masks
grip the telescope tube gently but firmly with three metal posts which have
non-scratching silicon sleeves to protect you valued telescope surface. This
prevents slippage, whilst allowing the mask to remaining perfectly central.
Because of this 3-post mounting, the mask remains centered, whilst fitting a
wider range of telescopes.There is a myth about different Bahtinov grating
pattern is required for different focal length telescopes. There is no real
practical reason for the use of special patterns for different telescope types
and focal lengths. In fact, the frequency and angle of Bahtinov mask patterns
aren’t really that important. The diffraction effect is so sensitive to
changes in focus, that the results are excellent regardless. Please be assured
that these focusing masks will work excellently for both reflectors and
refractors with whatever focal length. All you need to do is to measure your
telescope tube size and choose the right size of the mask.

Features

  • Make sure this fits. by entering your model number.
  • Bahtinov masks take the guesswork out of focusing and even get over the seeing conditions as it is a mathematical type approach to the task.The best focus for your telescope quickly and easily.
  • Suitable for use on all types of telescope - reflectors, rafractors, Dobsonians, Mak-Cas and SCTs. They are made from precision laser cut enforced plexiglass, which is stiff and long lasting. They will never be brittle in the cold, unlike some other masks which are made from normal plastics.
  • The masks grip the telescope tube gently but firmly with three metal posts which have non-scratching silicon sleeves to protect you valued telescope surface. This prevents slippage, whilst allowing the mask to remaining perfectly central. Because of this 3-post mounting, the mask remains centered, whilst fitting a wider range of telescopes.
  • They are made from 2mm thick laser cut plexiglass and the securing screws are capped with soft plastic so that they do not damage your telescope.These high quality Bahtinov masks are adjustable to fit a wide range of optical tubes, unlike masks which are only able to fit one telescope. They have adjustment latitude of about 215-260mm, depending on model, in aperture making them very versatile.
  • Please be assured that these focusing masks will work excellently for both reflectors and refractors with whatever focal length. All you need to do is to measure your telescope tube size and choose the right size of the mask (contact us if you are not sure where to measure).

Product Details

  • Product Dimensions: 5.1 x 5.1 x 0.1 inches
  • Item Weight: 1.6 ounces
  • Shipping Weight: 1.6 ounces
  • Item model number: SKU_AM_BFM200

Shipping & Handling

Orders are shipped within one day and tracking information is provided as soon as it is available from our carriers

Please ensure the correct shipping address is provided at the time of purchase. We cannot correct your address after purchase. We will not be responsible for incorrect addresses or undeliverable addresses.

Shipping to AK, HI, PO boxes, or APO addresses is not provided.

Return Policy

Returns within 14 days are excepted and a 15% restocking fee will be charged.

Filed under: Eyepieces & Accessories