Now, I also observed with color filters as they are used in planet observations to create a "classic" rGB composite. The "r" is written small, since it is only a pseudo-red channel. I used a yellow filter, but encoded the resulting sketch as a "red".
This time, I used a 8"-SC for polarization observations without any prism to have a rotationally symmetrical beam path, since reflections under a certain angle have a major impact on the polarization state of the incomming light. I am not sure, if I can do so for other objects. In case of M1, I had really problems with this set up because the polarization filter holds back a huge amount of light...