If your only looking at a defocused light from the ball bearing you wont need filters for it. With my 8" f/4 I have to use extension tubes to see my "star" which is about 30 metres from the scope. I was thinking of putting one on my neighbours house when they aren't looking
But yeah you will need the extension tubes for anything less than say 50-100 metres. Try do it when it isn't hot either, those heat currents can really be annoying.