andrew,
the large black "hole" off to one side is your secondary. it appears to me that you have the focus too far in or out. mine works better defocusing outward. for a star test you need to
barely defocus. the rings you'll see are hard to define until you see them for the first time and from then on you'll know what your looking for. there should be several that appear(not just the one)
btw your collimation is out!
