So cool, isn't it Rod!
The Helix is one object that does really surprise you on your first viewing of it. Such a distinct smoke ring. My first and so far only view of it was in June. While visible without a filter, an OIII does make it really stand out, and gives a more volumous shape to it. Cloud has made it impossible to have another crack at it. The Helix has been on my to-sketch list for some time. Scott Mellish has
a sketch of the Helix on ASOD. He too used an OIII filter to bring out details.
My 1.25" OIII filter is the modestly priced GSO one. Does a brilliant job! Without it a lot of nebulae would be close to impossible to see from my home in Sydney. The most surprising part was seeing dark pillars in
Eta Carina with my 8" f/4 scope (like Alistair's), from home. I could only see these from home with the OIII in this scope. I've recently purchased a 2" OIII filter for $100 on ebay from
Omega Optical, the folks that make the DGM line. A dead-set brilliant filter for the price.
Alistair, this sketch will also give you an idea of what to expect with the 30mm Superview eyepiece in your 8" scope.