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Above is a f10 mask suitable for Schmidt Cassegrains

above my own setup consisting of Celestron C925 and William Optics ED102 Megrez

 

WILL BE SENT BY 1st CLASS DELIVERY IN THE U.K.

Contact me [email removed by eBay] or telephone 01842 860736 
 
Bahtinov  Mask for Celestron NexStar 4SE
 
Made from Acrylic. I experimented with plywood but found it warps too easily
 

The unique design prevents the mask from rolling away

If you are in doubt then please measure the outside diameter of you telescope tube and let me know what it is.

I am very happy to make you a bespoke mask if you can't find one for your telescope

It will take less than 1 minute to achieve perfect focus with your new mask and will mean you spend more time imaging photons rather than focusing them

3mm thick Matt black Toughened Acrylic so no reflective light.

Unlike ones made of ordinary Acrylic or Perspex these ones will resist cracking and breaking during normal use.

However they are NOT unbreakable so treat them with the same care as you do with your lenses and camera equipment, a good precaution would be to tie a short length of string through one of the lower slots then tie it around your scope, that way if you forget to remove the mask before slewing your scope the mask will not drop to the ground but only a few inches.

Light weight so you wont upset the balance on your scope.

Precision laser cut.

M6 white nylon (which can be a visual aid in the dark) bolts to hang the mask over the front of your scope,

these are removable for easy storage of your mask after focusing.

I mark the extended corner with reflective tape this is so you can find it again in the dark.

Also like most people I have from time to time forgotten to remove the mask before imaging,

the bright reflective corner makes it stand out.

Much more accurate than the old 2 hole or 3 hole Hartmann mask.

The pattern displayed in a Hartmann just gets slightly more in focus, which means the true focus may be off by a significant degree.

The Star Sharp Focus Mask

shows you exactly where the perfect focus point is every time, regardless of seeing conditions.

This unique design also allows more light gathering than a Hartmann mask allowing you to focus on a much dimmer star.
Special sizes are also available, just let us know. focal length, aperture of lens or mirror the outside diameter of your tube
THE LISTING IS FOR 1X BAHTINOV MASK. PICTURES ABOVE ARE GENERIC AND MAY NOT BE OF THE ACTUAL MASK YOU WILL RECEIVE AS THE SLOT PATTERNS DIFFER FROM ONE FOCAL RATIO TO ANOTHER.

I normally make these and post them out to you the day after the order is replaced.

ALL MASKS SHIPPED IN "PIZZA" BOXES TO INSURE THEIR SAFE ARRIVAL, ALSO THESE BOXES ARE EXCELLENT FOR STORING YOUR MASK IN WHEN NOT BEING USED.



Great news for DSLR users!
APT (Astro Photography Tools) has added a Bahtinov routine to the program to aid users in achieving perfect focus while using a Bahtinov mask.

Also works with ASCOM compliant CCD cameras too!