Roger, I had this discussion with Craig Stark the author some time back before v2 was released. Craig was basically of the view that ICNR was not the best approach, as such Nebulosity did not support this feature. I am not sure if his position has changed on this, but you maybe better of asking him direct or via trhe yahoo support group. I found Craig to be very friendly and easy to approach, with quick response to such enquires.
Craig did put forward that he did not belive that ICNR was the best method. His opinion back then was that it is better to take the dakrs seperately than to waste the time on dakrs which could be spent capturing light frames. Also I think it has to do with the fact that if you caputure 50 light frames you dont necessaryly need 50 dark frames. You can probably do with 10. So if you used ICNR then you would waste time on 40 extra dark frames. Also if your imaging train was not changing and temprature drop was not very substantial during your run you would be ok to reuse 10 dark frames as a master set for all your light frames witht he same exposure time as the dark frames.
I have V2 but have not really used it so am not sure if the ICNR support is now included or not.
Here is the link to the yahoo user group.
http://tech.groups.yahoo.com/group/s...nomy-software/
Regards
Fahim