Thanks all for the comments. This is a whole new game for me and I am just starting to learn.
Cloudy weather has been interfering with more progress.
Had a bit of a play with colour data from the 300mm lens and the narrow band stew image.
This is the 300mm lens image 5MB
http://d1355990.i49.quadrahosting.co...4/300mm_10.jpg
This again is the NB stew2 image 6MB
http://d1355990.i49.quadrahosting.co...NB_stew_02.jpg
This is a combination with the same colour channels simply combined 6MB
http://d1355990.i49.quadrahosting.co...m+stew2_10.jpg
The small images below are in the same order.
Bert