Joan,? Just some thoughts on the matter:?
The calibration works best when the frame edges are clear, so it should be performed on a field of stars.
I say this just in case you are are trying to calibrate on a dark field, when i don't think it will work.? I have fallen into that trap and been advised.? ?Also 4 frames is x8 on the WAT910HX - again something else to be aware of and another possible trap for newcomers (like me).?
Tim
Tim Haymes