View Single Post
  #11  
Old 11-10-2008, 01:01 PM
sjastro's Avatar
sjastro
Registered User

sjastro is offline
 
Join Date: Jun 2007
Posts: 2,926
Quote:
Originally Posted by gregbradley View Post

I also often use Gradient Xterminator early on after levels/curves if there is too much background green or red etc. Not sure why I sometimes get this even at a dark site - perhaps lower altitude images suffer from atmospheric extinction and also this large chipped camera is more sensitive to the need for good flats than other cameras I have used.

Greg.
Hello Greg.

Are your referring to a gradient or colour cast?

It's usually blue filtered images that suffer from atmospheric extinction.

I occassionally have green/magenta gradients in my images even though my site is reasonably dark.

It finally dawned on me the gradients were processing induced. I found my RGB images were gradient free but when combined as an LRGB the gradients appeared. (The L images were also gradient free). It was caused by overstetching the L images.

Even the choice of combining software can effect gradients.

Regards

Steven
Reply With Quote