bridge

Why does my prusa create such bowl-shaped bottom?

PLA Temp was set to 205°C Bed 0° Retraction 10mm (I tried lower values but it starts oozing) Retraction Speed 50mm/s, Bridge Speed 40mm/s.
Fan is kept always on at 35% (Slic3r settings)

You can not fully avoid this, that is where support comes into play
But in general you can say that the bridging works better at lower temps.
Best would be to have a bridging temp that is just enough for proper extrusion and layer bonding.
Keep in mind the plastic is still hot and flexible when you make a bridge, so sagging can't be avoided completely.

ok thanks man :-)
I was on a roll to get object as much as accurate possible