Rokō no Hiketsu 露光の秘訣 [The Secrets of (Photographic) Exposure]
Sawa Kurō 佐和九郎, author
Onchi Kōshirō 恩地孝四郎, book design
ARS アルス (Arusu-sha アルス社), publisher
Shōwa 29 昭和29 
Hardcover volume 21.3 x 15cm bound and opens Western style. Yellow front cover with black geometric design and silver line accent and printed title and black rear cover. Vol 1 in a series by the publisher entitled Sawa Shashin Gijutsu Kōza 佐和写真技術講座, [Sawa Course in Photography Techniques] by author Sawa Kurō 佐和九郎. 240pp of Japanese text and reproduced photos. Colophon has a publisher’s seal and a photo negative with in glassine tipped in.
Author Sawa Kurō 佐和九郎 was employed as an engineer in a job related to electrical engineering when he took up photography as hobby. In 1921 he opened the photography shop Hinomaru Shōsha 日の丸商社 in Ginza; the same year he founded the photo magazine Kamera カメラ [Camera]. He went on to write numerous books on the subject of cameras and photography.
Book design by Onchi Kōshirō 恩地孝四郎 (1891–1955). The accomplishments of Onchi Kōshirō 恩地孝四郎 throughout the first half of the 20th century begin with his eminence as a printmaker. He was an innovator who domesticated the ideals of abstraction and "creative printmaking" in Japan when still in art school. From his early years, working with Takehisa Yumeiji 竹久夢二 among others, he began a long career as a printmaker, book designer and book illustrator. From the very beginning of his life in the arts he was the center and focus of the Creative Print Movement Sōsaku Hanga 創作版画, surrounding himself with fellow artists who took inspiration from his dedication to the cause of self-expression. His works are held in institutions internationally.
Publisher sheet folded to 18.3 x 12.7cm laid in. The title of the publisher sheet is Dokusha to Chosha 読者と著者 [Reader and Author] and the text on the first page is by the author. The inside pages feature essays by two university professors in the field of photography and information about the course. The rear page features a photo illustration and ad for the next book in the series, カメラとレンズ [Cameras and Lenses].
Housed in a yellow and black case 21.7 x 15.6cm with printed title, author and publisher, that opens Japanese style, with the opening to the left. Wear and dust staining to case and stain on front cover of book as well as a chip.