Cutting a 8' Silk diffusion screen smaller
 

There where no 6' by 6' silks in stock so I bought a 8' one because I needed it quick.

Any suggestions for cutting it down a little?

I am not sure what the best size is too for outdoor filming, mostly thinking of doing medium - close up shots with it, but not sure what the best size is for different focal lengths,

help appreictaed!