P.A. Scheen, Lexicon Nederlandse Beeldende Kunstenaars 1750-1880, The Hague 1981, ill.no. 363
Koster was one of the students of Bart van Hove, who was a teacher at the Hague drawing academy. Koster belongs to the generation of Wijnand Nuyen, Antonie Waldorp and the young Bosboom. In his early years, his works joined in with the Dutch landscape tradition. He painted townscapes with rivers and ships with a great deal of attention for detail. Later on, his style of painting became less graphic, yet one cannot say he joined the style of the Hague School.
Koster made study trips to Germany and England. In 1858, he was appointed director of the Pavilion Welgelegen in Haarlem, the former residence of the banker Hope, where the Dutch state had housed its collection of contemporary art. The pieces acquired at the bi- or tri-annually held Tentoonstellingen van Levende Meesters ended up here. The purchasing policy and the way of preservation were far from perfect as was shown in Victor de Stuers' pamphlet Holland op zijn smalst. Koster held this position until 1878. A few years later, the entire collection was housed in the newly built Rijksmuseum in Amsterdam. Koster moved to The Hague. He died in Dordrecht on 8 January 1892.
Koster specialised in sea and riverscapes. He executed his pieces in oil paint, in aquarelle and in lithography. His work is true to the tradition of Dutch Romanticism for the skilled craftsmanship is more striking than the spirited inspiration. His work is well represented in its many versions in Dutch museological collections.