My nickel supra 1-4 x20 gives very clear focused image at 6feet at its lowest settings. My Zeiss 6x42 is slightly fuzzy at 15, but clear enough to take a shot. My Swarovski 4-12x50, is in focus on 4 power at 15 feet, but at top power it's more like 30 to 40. Have nt a clue about the paralex bit, but in the real world at close range not much to worry about.