In case the time poor star splitter missed it in a previous post I grabbed this link from the last on Sirius and is a great article by the famous William Herschel on his viewing techniques, with a lot on optics and light.You will need time and a cloudy night
to fully absorb this. PS: you can see I am getting viewers' cabin fever
http://rstl.royalsocietypublishing.o...ge=1&view=FitH