View Single Post
  #5  
Old 09-06-2008, 11:49 AM
Terry B's Avatar
Terry B
Country living & viewing

Terry B is offline
 
Join Date: Mar 2006
Location: Armidale
Posts: 2,790
Quote:
Originally Posted by erick View Post
I'm sure I read somewhere that there is an argument for having a smaller aperture for solar observation. I recall it goes something like - you have buckets of light, so there is no need for a larger aperture to collect light. When observing the sun, it is normally in a heated atmosphere (ie daytime ) and hence stability of the air column between scope and upper atmosphere is important for resolution. The maths apparently suggests that a smaller aperture will provide better resolution that a larger aperture under such conditions. Well I think that is what I read.

Hence the many offaxis small aperture solar filters available - it's not just for lowering the cost.
Yres but the small holes a probably too small. Angular resolution is proportional to the diameter of the mirror and the resolution gets pretty low with a 40mm hole like on my endcap.
The solar telescope at the ATCA has about a 120mm mirror.
See http://www.ips.gov.au/Main.php?CatID...cName=Overview
Reply With Quote