What Smerf suggests is all well and good if your monitor supports 15khz Horizontal signals. Most don't and most haven't. Here in the U.S., only a few from the late 80's to early 90's ever did. "Multisync" my arse! lol
So... long and short of it is this: The Picasso card is NOT a flicker fixer or scan doubler. It only allows passthru of the original Amiga video out through its card in the very unlikely chance you have a true multi-syncing capable monitor (15khz).