2022-03-23 M42 MOUNT SPIRAL: KMZ OKC1-50-4(OKS1-50-4) （OKC-1）50mm F2 (16SP) https://spiral-m42.blogspot.com/2019/05/kmz-oks1-50-4okc1-50-4-50mm-f2-16-sp.html
