Hi John
Think our posts just crossed. I remember most of the tutorials on spectroscopy recommended the standard spectro `candle` Vega for correcting but as you may have seen in my post above I`m still a bit unsure if I should be using a fresh correcting spectrum for each star, logic would assume that we should for more accurate correction the thing is finding a star of similar class to the one you are observing within a near enough distance away which all takes time and with the British weather we `enjoy` time is not always a luxury we can be sure of!
cheers
Steve