Invalid files DPX -> TIF

[friolator]

If your input is DPX then I expect that "-define png:swap-bytes" does nothing at all, and is best removed from the command.

You're correct. I was able to eliminate that and the image can go direct from DPX to TIF now. That was a remnant of the problem pointed out earlier that caused a noisy image during the conversion. In the versions I've got installed now, that's not an issue.