http://www.lensrentals.com/blog/2010/09/lens-repair-data-4-0 シグマレンズ 脅威の故障率でレンタル取り扱い停止 The lens has proven so unreliable that we’ve stopped carrying it. The following three lenses have been discontinued for this reason: Sigma 150-500 OS Sigma 120-400 OS Sigma 50-500 OS 18% AF failure みんなも壊れる前に売ったほうがいいよ