please refer to the table as below Focal Length Field of view (e.g) Recommend monitor distance 2.8mm 98.5° About 3 meters 4mm 79° About 6 meters 6mm 49° About 10 meters 8mm 40° About 20 meters 12mm 23° About 30 meters 16mm 19.2° About 50 meters 25mm 12.4° About 80 meters ※Field of view angle varies from different model, refer to the official   website for accurate parameter