Sounds like they always had 16:9 footage, and just cut it down to 4:3 for the original broadcast.
All episodes were filmed in 16:9 wide-screen, although Stargate SG-1 was broadcast in 4:3 aspect ratio in its first years.[40] The transition to the broadcast of episodes in the wider 16:9 ratio gave directors more freedom in frame composition.[41] The first three seasons of Stargate SG-1 were filmed on 16 mm film, notwithstanding scenes involving visual effects that had always been shot on 35 mm film for various technical reasons. After a test run with the Season 3 finale, "Nemesis", Stargate SG-1 switched to 35 mm film for all purposes at the beginning of Season 4.[42] Digital HD cameras were used for filming beginning with Season 8.[39]
I've started to buy the Blu Ray set a couple times but the lackluster reviews with respect to image quality have kept me from it. My *coughs* archival copy *coughs* of the series is of reasonable quality. *loses balance on fake pegleg, crushes fake parrot*
Sorry. I'm out of practice. Wife won't let me sail those waters anymore.
I aquired SG1 on a lan party a decade or so ago, then when I moved out from my parents I bought the entire SG1 and SGA series on DVD, then a few years ago I built a new computer that could easily handle ripping DVDs while playing minecraft and watching YT, so I finally got to replace most of the seasons that I aquired at the lan party with proper DVD rips.