Thank you Terry, you answered my question.
Wondered what the advantages were in completely rebalancing my rig and adding the SBIG + AO through an 80mm scope to go with a 200mm RC.
I suppose if I was to use it a lot I could gain some benefit from it, but really when I want to do a wider field I stick my DSLR with a focal reducer into the FS 60. Very wide then though not as wide as the nifty 50'!.
Will consider more , ooohhhhmmm!
Graham