Hi Ted, thanks! Yep, I tried Autostakkert and I use Registax for my planet images. The problem I had was that with an un-tracked video clip of the Moon, Registax and Autostakkert couldn't seem to cope with the crater drifting all the way across the FOV. It would lose the features after a while, leading to a very blurred image. You can't use the 'object detection' methods in Registax or PIPP because a frame filled with Moon is all an 'object', and so for me, none of the other programs followed the craters as they tracked across the field. AviStack did it perfectly, made me very happy! However if you know how to get Registax or Autostakkert to follow a crater from left to right over the field, please let me know!