https://notion.blog/%ec%ba%90%eb%85%bc-%eb%b0%94%eb%94%94%ec%9d%98-%ea%b3%b5%ec%8b%9d-%eb%9a%9c%ea%bb%91-%eb%a6%ac%eb%b7%b0-%ed%8c%ac%ec%bc%80%ec%9d%b5-ef-40-mm-f-2-8-stm-micro/