SH2-33 (Sharpless 33 ) This is an interesting object that does not respond to narrowband filters at all, so I would not bother. The object is very faint, and you will need a long exposure in the luminance which should be a clear filter. To get the color, you will also need to take long exposures because it will be very hard to color the luminance if you go really deep with it. The three color channels all pick up about the same, but red and blue seem to be just a big stronger. Using a wide field of view may pick up more of this object because there seems to be quite a bit of it around the edges. I would shoot this object in the darkest skies you can find to bring out the contrast. For a complete list of the Sharpless Catalog visit my main site at http://www.sharplesscatalog.com