Bert's image of the Helix Nebula prompted me to take a look at some of my data from last year. Viewing it normally does not really show much detail. Only inverted really shows all the shells and faint traces of gas of the Helix.
There appears to be 6 maybe 7 shells on lower side of the main shell, I'll leave that up to everyone to guess how many there are.
This data is 60 hours worth in Ha
Click here for the larger resolution image which shows all the shells.
Not bad for a 4" scope or should I saw straw
.