Well, the dot is not there with no binning (maybe because the image is less sharp?). It is there only at the two highest resolution levels and with binning and it stays in the same position (more or less) if I move the camera. It can be easily eliminated in a program like Photoshop though.
I took a short video of the full moon at the highest resolution with no binning and although there are turbulences being full moon etc. the video is clear in itself and there is absolutely no dot.
Actually the no-binning video was better than I expected (I usually use 2x binning). On a day with good seeing conditions I should get really good videos at high magnification.
It doesn't seem to be an uncommon problem anyway:
http://stargazerslounge.com/topic/20...nsor-cleaning/
Oh, there is a thread here too:
http://www.iceinspace.com.au/forum/s...d.php?t=114573
So would this be good for the NexImage?
http://www.ebay.com.au/itm/Camera-CC...item4ad7630fb2