A painter in his workshop Rembrandt investigates the usefulness of linear perspective Maer want sulcke afteyckeninghen niet al op glas of deurluchtighe stoffen begheert en worden, oock datmense scherper en suyverder wil hebben dan soo doenlick is, boven dien dat de ghestichten of saken diemen afteyckenen wil, somwijlen niet wesentlick voor t'ghesicht en staen, maer alleenelick int ghedacht, soo sijnder seker reghelen gevonden, deur welckmen de schaeuwen der verschaeulicke saken met haer vercortinghen, verlanginghen, en veranderinghen, op haer eyghen verschaeude maet ghewislick teyckenen can. (Simon Stevin) [English version: see Appendix 2 : 02] Although not signed and not dated, the painting discussed here is since 1925 generally ascribed to Rembrandt. [#RRP1] The most accepted year of execution is 1629, but sometimes one finds 1628. A recent new assessment of its size in the Boston Museum of Fine Arts resulted in a size of 24.8 x 31.7 cm. These measurements have been applied here, and not the usual 25.1 x 31.9 cm. The reproduction below is fairly light so that in the rather dark area at lower right the details are recognizable. ill. 1