A couple of nights back I looked at 31 PN with a 16" scope.
NGC 6309 looks like a double star with a 13mm EP (139x) and UHC filter.
A 9mm EP (200x) shows it is a PN and mag 12 star.
https://picasaweb.google.com/1100488...70033830034498
Images of 97 PN are here.
https://picasaweb.google.com/1100488...m95-XF98SCggE#
You can compare their sizes because they all have the same 14' field.
The images are from wikisky.org
Kent Wallace's PN data is available here
http://www.blackskies.org/intro.html#Files