Hi Rafal,
In this case, make sure you’re using the easy setup “Blackmagic HDTV 1080i50 – DVCPRO HD”.
Create a new sequence and drop your clips into that sequence. Check your View > Video Playback settings and ensure that it is set to “Blackmagic HDTV 1080i 25Hz – 8 bit (1920 x 1080)”
Next, go into the DeckLink Preferences and turn on down conversion.
regards
Kristian Lam
Blackmagic Design