The standard values of the Scenery slider are is in the table above. Since FSc is equipped with ORBX Global AND the settings of sceneries are linked to the performance of your PC, you should follow this table below. Find out the specs of your PC and set the Scenery slider accordingly. All other suggested manual settings are not advised. Remember that all manual changes in [TERRAIN] will be overwritten when you move the Scenery slider. Therefore it’s pretty useless to make manual changes.
Look at your own PC specs and set the slider accordingly to have the best performance.