You asked
Is the nikon z dx 50 250mm f 4 5 6 3 vr good for video?
I'd call it a poor pick for vlogging, but it can work for other video. The lens is stabilised and autofocuses, which helps handheld shots. But on APS-C it frames like 75-375mm on full frame, so it's a telephoto. Vlogging wants a wide view, roughly 16-20mm full-frame equivalent, so the vlogging checklist points elsewhere. Its aperture also gets darker as you zoom, so it needs good light.
The lens fits APS-C bodies such as the Nikon Z50 and Nikon Z30. Whatever you pick, budget for sound too, as covered in the audio section.
Written by Claude from this site's pages.