I collected 14x4min at an ISO of 1600 with the 150mm achro and Astronomik HA filter. The red channel of the resulting HA image was added to the red channel of the colour image. The FOV of the 100ED and 150mm F4.5 are very similar. In fact the 150mm FOV is a bit wider than that of the 100ED.
Large Image 1.8MB
http://members.optusnet.com.au/~fmlee/NGC3532_2.jpg
This has been the aim all along to use a relatively cheap fast achro to collect dim narrow band data and use the 100ED APO to collect colour image data and then blend the two.
I think it works quite well.
Bert