http://qhyccd.com/ccdbbs/index.php?topic=1141.0
QiuHY (the maker of the QHY cameras) mentioned a few days ago that he was going to contact craig stark about adding proper support for 4x4 through nebulosity 2...
Thinking about it now, I've not used 4x4 in neb2 at all, I did however use it once before in CCDCAP, which worked...
The camera supports it, as do the drivers, however Nebulosity 2 at this time does not.
CCD Cap should have come with your QHY8, if you need to use 4x4 for something, use CCDCap untill Craig adds neb2 support..
Alex.