@Igor_Braun
My way to activate FHD 48p is (preview Options: Auto):
1. enable live view
2. set your Settings (manuel mode: shutter, aperture and iso)
3. press play 2 times (wait 2-3 sec.)
4. press "+" (wait 2-3 sec.)
5. repeat step 3. and 4.
6. enter crop rec 48p in ML (press half shutter to exit ML) -> and you will see a half frozen live view (top is liveview and bottom frozen) -> this is correct
(7). sometimes it doesn't work and you must disable 48p first (press half shutter to exit ML), and repeat step 4. - 5. or go back to step 2.
If you want change shutter, aperture or iso -> disable crop rec first and go back to step 2.
-> if you forgot disable crop rec first (blackscreen!!) -> disable live view, disable crop rec, enable live view and go back to step 2.
Set correct shutterspeed is important! 1/33 --> 1/58, 1/41 --> 1/86, 1/45 --> 1/100(ML menu) 1/50 --> 1/130, 1/64 --> 1/320, 1/82 --> error