#1  
Old 10-04-2011, 04:15 PM
solissydney (Ken)
Registered User

solissydney is offline
 
Join Date: Mar 2006
Location: Sydney
Posts: 660
Vignetting

I read on some forum that vignetting is caused by the bottom of the focuser protruding into the light path, which I doubt.
If it is the case the dual purpose of prime imaging and wieving will be difficult.
Reply With Quote
  #2  
Old 10-04-2011, 04:33 PM
Gama's Avatar
Gama
Registered User

Gama is offline
 
Join Date: Dec 2005
Location: Melbourne
Posts: 1,121
Vignetting is "ANYTHING" in the path of the light cone (Blocking).
Focuser, adapter, baffle's, etc.

Theo
Reply With Quote
  #3  
Old 10-04-2011, 04:38 PM
tlgerdes's Avatar
tlgerdes (Trevor)
Love the moonless nights!

tlgerdes is offline
 
Join Date: Mar 2009
Location: Sydney
Posts: 2,280
Vignetting is caused by the uneven illumination of the CCD sensor. There are lots of contributing factors, but anything that somehow limits the lightpath to the CCD can be a cause.
Reply With Quote
  #4  
Old 10-04-2011, 05:33 PM
Moon's Avatar
Moon (James)
This sentence is false

Moon is offline
 
Join Date: Oct 2008
Location: Melbourne
Posts: 1,147
Quote:
I read on some forum that vignetting is caused by the bottom of the focuser protruding into the light path, which I doubt.
If it is the case the dual purpose of prime imaging and wieving will be difficult.
Imagine if your focuser was 30cm long and only 10mm wide. Would you think it could cause vignetting?
If the focuser protrudes into the OTA, this won't cause too much vignetting (and I suspect this is what you are talking about) but it will create nasty diffraction. However a long and narrow focuser will cause vignetting.
James
Reply With Quote
  #5  
Old 11-04-2011, 09:28 AM
solissydney (Ken)
Registered User

solissydney is offline
 
Join Date: Mar 2006
Location: Sydney
Posts: 660
Vignetting

Very interesting.
Thanks for your replies
Ken
Reply With Quote
Reply

Bookmarks

Thread Tools
Rate This Thread
Rate This Thread:

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 03:42 AM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.
Advertisement
Testar
Advertisement
Star Adventurer
Advertisement
EQ8-R
Advertisement
Bintel
Advertisement
Lunatico Astronomical
Advertisement
Celestron RASA
Advertisement
Astromechanics
Advertisement
Astronomy and Electronics Centre
Advertisement