Friday, December 26, 2008

Bahtinov mask.

I made a focus-mask for my C9.25 the other day. It's called a Bahtinov mask and it's the new concept for focusing scopes.
Here's a site that has downloadable templates for a variety of scopes. Here's one for a C9.25
I made mine by printing out the template, A3 size, and then was lucky enough to find a sheet of thin black plastic. I taped the template to the plastic, cut out the slots and voila! here's the finished article:-

I also found some metal lugs that I pushed through the sheet as marked on the template, this enables the mask to sit on top of the scope.

Below are the results from tonights test run with my DMK; when the image is symmetrical the star is in focus.

Really easy to make and very effective :-)