Yea I was wondering if last 2 ones were long exposures, I do have some old ND filters (dont think any of them fit my lens though), and as general all my lenses are quite dark (old manual lenses) so as I generally do budget photography - using old manual lenses and all of them are full frame as well, so less light for my tiny aps-c sensor :)
Should try this some day....
RE: Storm photography - part I