Go Back   IceInSpace > Equipment > Equipment Discussions
Register FAQ Calendar Today's Posts Search

Reply
 
Thread Tools Rate Thread
  #1  
Old 22-04-2010, 01:52 AM
avandonk's Avatar
avandonk
avandonk

avandonk is offline
 
Join Date: Aug 2005
Location: Melbourne
Posts: 4,786
Bahtinov Mask Diffraction Pattern Movie

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.co...bahtinov01.gif


Enjoy the movie.

Bert
Attached Thumbnails
Click for full-size image (RZ_CR_IMG_0646.JPG)
34.6 KB36 views
Click for full-size image (RZ_CR_IMG_0640.JPG)
35.5 KB46 views
Reply With Quote
  #2  
Old 22-04-2010, 09:21 AM
avandonk's Avatar
avandonk
avandonk

avandonk is offline
 
Join Date: Aug 2005
Location: Melbourne
Posts: 4,786
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
Reply With Quote
  #3  
Old 22-04-2010, 12:01 PM
joseph (Joseph)
Registered User

joseph is offline
 
Join Date: Mar 2010
Location: Hong Kong
Posts: 4
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.
Reply With Quote
  #4  
Old 22-04-2010, 05:50 PM
Exfso's Avatar
Exfso (Peter)
Registered User

Exfso is offline
 
Join Date: Sep 2006
Location: Adelaide
Posts: 1,699
Even better when used in conjuntion with the Bahtinov Grabber, that really fine tunes the focus
Reply With Quote
  #5  
Old 22-04-2010, 06:25 PM
multiweb's Avatar
multiweb (Marc)
ze frogginator

multiweb is offline
 
Join Date: Oct 2007
Location: Sydney
Posts: 22,078
Cool - I got a couple I did a while ago with a hartman mask then a bathinov mask. The hartman gives you that bright flash when you hit the sweet spot.
Reply With Quote
  #6  
Old 22-04-2010, 08:46 PM
duncan's Avatar
duncan
Duncan

duncan is offline
 
Join Date: Jan 2007
Location: Weipa FNQld
Posts: 1,091
Well done Bert. I must admit i love my Hartmanns. Should have made one ages ago.
Cheers,
Duncan
Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +10. The time is now 07:31 PM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Advertisement
Bintel
Advertisement