Here is last nights effort. Managed to get frames for 1min,4min and 8min for both HA and O3. Using the 150mm achromat.
I summed each of the two 8 min frames to get one 16 min for HA and O3.
Easyhdr used the two sets to give me two images for HA and O3.
Recombined in IP.
Large image 1.2MB
http://members.optusnet.com.au/~fmlee/M42_NB_ACH.jpg
Not bad for an achromat.
Bert