Studied in the Studio of William Skulle, later Studio Miesnieka and K. L. Liberta (1926). In 1936 he graduated from the workshop of Species of painting of V. Purvitis in the Latvian Academy of arts with the thesis "Threshing".
In 1944 he went to Germany and in 1945 returned to Latvia.
The artist worked as a restorer. He was a teacher at the Riga art school by J. Rozentals (1945 – 48) and Riga secondary school of applied art (1948 – 50). O., Caldas worked as a graphic designer in the plant “Māksla” (1950 – 58) and also was a member of the magazine “Māksla” (1958 – 60).
In exhibitions the artist has participated since 1935.
Since 1957, O., Caldas was a member of the Union of artists.
Literature:"Māksla un arhitektūra biogrāfijās", 3. is. - R.: a/s"Preses nams", 2000. – 256. page, J. Skulme, 21.p.
