Hi Vin — It sounds like you’re trying to use a camera lens afocally in front of the PVS-14 objective. Your PVS-14 needs parallel light beams hitting the objective (you can see this in the diagram you linked) to work afocally, but the camera lens is producing a light cone (like the telescope is in the diagram), so you won’t ever be able to reach focus the way you’ve been trying. Since you’re tinkering … if you could somehow add an eyepiece between the camera lens and the PVS-14 objective, this might work. Otherwise, you need a different night vision device, like a Mod-3, that has a removable objective lens.
Steve