Parallax - Smash?

After I said Parallax, the four were still staring at me blankly or with a smile saying that they didn't understand anything.

"O-Ok… Parallax… what is it?" Olivia asked, fidgeting.

"I told you guys we should do it in the actual class, heh. Well, let's just say that you four got a little~ heads-up compared to everybody that will be joining in the future. To put it simply, it is a phenomenon when the target and the reticle are on the different planes within the scope. You'll notice it if we start looking at targets at long range and the reticle starts to move away from the target you're aiming at."

"Then what do we need to do?" Chris asked.

"Well, we'll need to make some adjustments so it wouldn't happen. I guess we'll be doing two more things instead of one to be completely done. Well, it depends if you want to go through with the second adjustment." I replied.

"Y-Yes… I mean… how?" Chris almost hit his head on the table from not asking specifically.