It is in his example.
I was hoping for a setting or a procedure or something besides "it just works" because that gives me nothing to go on. Default renderer. I don't think graphics driver matters.
I'm starting to doubt I'm reasonable, but what I can say is the preview is far more optimistic and I don't see why there should be any discrepancy at high quality levels, let alone the big differences I am experiencing.
I don't believe it's relevant (or it shouldn't be, it's a text overlay) but the source data is 640x480 and I'm rendering it at 1024x768. Same result at 640x480 of course, I just hoped the text would be better and for unrelated reasons I need to upsize the format.