Fixture Placement on augment

Hi All,

This may have been asked already, apologies if it has 

When placing fixtures in augment how do you know which way the base of the fixture is facing I.E is it front pointing upstage or downstage

I hope this makes sense as when i did it a few weeks ago I didn't know if the fixture was the correct way when putting clamps on 

I did all my show offline so you can imagine the pain