It was at f/7.1. The lens itself is f/5.6 at widest zoom, i think. Not fast by any means.
I don't own a 2x teleconverter either and don't particularly want to buy anything new for the eclipse.. but I do want better photos than the one above!!
Will have to try afocal through the newt - can't do prime focus. It wouldn't come to focus and I don't have the necessary adapters and t-threads anyway.
Thanks for the input.