Hehe , I see your problem . And yeah , LP filters are very expensive ( I use lumicon ones in 1.25" and 2" ) , but I think UHC are better ( expensives too
) . Seeing your shots , the one taken with the canon is pretty impressive considering the pollution you got in your neighbourhood
Another thing about focusing : I found that focus to infinity isn't accurate on my lens , so I had to use Live View on a bright celestial object , and we got luck to have Jupiter at the zenith
and to my surprise , the focus point was around 8-9 meters on the scale .
I can't wait for late November/early December to be able to shoot toward our southern celestial pole and more precisely both magellanic clouds
This time I'll use my equatorial mount and autoguiding . I'm sure the 70-200 f/4 will shine there