the shades aren't even visible from earth. they are like dust or fog that don't let 2-4% of sunlight through. To have "sharp" shadow like you are proposing you

the shades aren't even visible from earth. they are like dust or fog that don't let 2-4% of sunlight through. To have "sharp" shadow like you are proposing you need to have a lot more shades (say 10 times as many) in a completely different (lower) orbit. they would also need serious station-keeping and control since they need to stay between earth and the sun. I think they would need at least hundreds of meters of delta-V a day