Some good nebula filters are the lumicon brand. I have a oIII and a broadband. I have an etx and the filters are helpful, but on such a small telescope they really dim the image, but it does stand out compared to starlight. I mainly use them on my 10" reflector. The filters do the most good on bigger telescopes that gather more light. In my opinion only a good broadband is needed for such a small telescope, but I agree with Ed in that it would be better to drive outside the city limits. Filters help, but reduce the contrast. It's just your flavor if you want a brighter image or more detailed. On orion on my etx, I see more contrast without a filter and the trapezium. With the broadband almost all the star disappear and I lose some of the detail, but it definately stands out and is easier to see. Hope this helps. Good luck and clear skies.

: I have a Celestron G-3 (90mm) and I'm looking for a good Nebula(r) filter. I live in the city, but I have a great view of Orion and would love to be able to see more of it. Any suggestions would be helpful. : Thanks.