Capturing MorphOS

Until now I always used VNC remote desktop to record MorphOS Videos of my FreePascal programs. I already bought before a standalone capture device but it did not work, even I set the screen mode to 720p or 1080p the capture device do not recognize the signal and therefore does not record anything.
Now I got an „Elgato Game Capture HD“ with this it seems to work when you set the screen mode in MorphOS to „1280×720 (50 Hz, 37.5kHz) 720p“ the 60 Hz seems not to work.