When I bought the G3 at Cherry Springs, I also bought an Oiii filter. I wanted a Ha filter, but he didnt have any. I ended up ordering one from Orion last week.
I figured theres no reason to wait for the Ha to come in to start taking narrowband images. The moon was shining brightly, on its way to become the supermoon which is to occur tonight. I took this image on 6/19/13 of M97, the Owl Nebula through the O3 filter.
There is very little Oiii emission in the Crescent Nebula, as seen here...
Note that these were taken under a bright moon.
I'm really looking forward to imaging the crescent with the Ha filter when it arrives.