I'm losing it.
There was a deprecated feature to bring back DV capture with Firewire, but I can't find it in V19 or V22. "Firewire" in Help produces no results.
Must be somewhere???
Probably a discontinued feature relying on old OS features that may no longer exist?
I'd keep old hardware and software around for that purpose. Archive the media and then edit it with modern versions of VEGAS.
Some alternatives here: https://www.vegascreativesoftware.info/us/forum/video-capture-support-dv-camcorder-via-firewire-1394--142109/
@PeterWright IEEE Firewire DV Capture has been long outdated. And using that technology now means you have to draw back for old hardware and old software to complete that task..... No current software supports it, So it makes no sense for Vegas Pro to continue also.
Back in the day for perfect DV captures without any dropped frames, i usually use WinDV, and its still there to download and use http://windv.mourek.cz/