View Single Post
  #4  
Old 15-08-2012, 09:16 AM
gregbradley's Avatar
gregbradley
Registered User

gregbradley is offline
 
Join Date: Feb 2006
Location: Sydney
Posts: 18,168
Quote:
Originally Posted by Gem View Post
I understand that since the refractor has no secondary mirror, it enables you to image over multiple nights without worrying about spikes not lining up. I image over multiple nights with my SCT since it corrector holds the secondary in place rather than the cross hair holder of a reflector.
Interesting point.

My CDK17 does not have many diffraction spikes, mainly only on the brightest of stars.

I can't say that spikes not lining up has ever been an issue over time though.

Perhaps the combining process tends to discard the misaligned ones. Not sure but I have taken images over 2 months of the same object and it did not cause a problem. I also don't use a rotator.

Greg.
Reply With Quote