I have been struggling to understand this as well. Typically, I pick a height that I like to focus at above the house, then let my eyes settle into the background, whatever that distance may be. Probably not a great process as I am a C21C shooter.Like Industem said.
Focus 30 yards out would be perfect for me but how can you focus at a given distance when ?
1 Every trap is different.
2 Most have the background way way farther out than 30 yds in front of the house.
Is there an explanation of this in one of the trap instructional videos?
In other words ( how) can you focus at a given distance looking at a clear blue sky????