Here is 2 deep Omega cantauri shots, I was not just after the cluster but wanted to see if i could reach the faint dust in the interstellar medium nearby.
I used the 6 inch f3.6 SN, 9x10 mins ISO 200 totally unfiltered, and the 300mm f2.8 lens from Bert, 7x10 mins ISO 400, with LPS filter. Both with modded 350D (clear AR coated glass over sensor)
Larger views
here
and
here (plane went through one sub)
The dust in the ISM is just there, on the 6 inch shot lower right, on the 300mm shot just right of upper middle.
Scott