Bahtinov Mask Diffraction Pattern Movie

[avandonk]

Finally got around to getting a Bahtinov mask for the 300mm lens.

Tested it between the clouds. It is far more sensitive than checking test exposures at high magnification.

The 300mm lens is focussed by a stepper motor. One thousand steps is a movement of 0.12 mm of the focus ring.

Below is a movie going from focus in one thousand step increments to +6000 steps and back to -6000 steps.

Animated gif 5MB

http://d1355990.i49.quadrahosting.com.au/2010_04/bahtinov01.gif


Enjoy the movie.

Bert

[avandonk]

I forgot to say the mask was a Kendrick for 80mm telescopes from Bintel.

Serial number on their (Kendricks) site BM-6004-P.

If you use the web generator for short focal length optics the bars get ridiculously thin.

I would say this mask would work for any lens it is just a matter of taking test images and zooming in to see the diffraction pattern.

Bert

[joseph]

That is a nice method to make the focus work. I use it, and this is so quick to make it in right position. highly recommend that. That is cheap, fast, and easy to use.

[Exfso]

Even better when used in conjuntion with the Bahtinov Grabber, that really fine tunes the focus

[multiweb]

Cool - I got a couple I did a while ago with a hartman mask (http://www.multiweb.com.au/astro/hartman.gif)then a bathinov mask (http://www.multiweb.com.au/astro/bathinov.gif). The hartman gives you that bright flash when you hit the sweet spot.

[duncan]

Well done Bert. I must admit i love my Hartmanns. Should have made one ages ago.
Cheers,
Duncan:thumbsup: