The Slave Ship at the event, to see it and be moved to increase British anti-slavery efforts. Placed next to the painting were lines from Turner's own untitled poem, written in 1812: The first impression that the painting creates is of an enormous deep-red sunset over a stormy sea, an indication of an approaching typhoon. Upon closer inspection one can discern a ship sailing off into the distance. The masts of the ship are red, matching the blood-red colour of the sky and the sickly copper colour of the water, which serves to blur the lines between various objects in the painting. The
Colour cast used to reduce the blueish tint caused by daylight. Blue filters reduce the orange colour caused by incandescent light. A variety of coloured filters in varying degrees of intensity are available. Kodak's amber filters, for example, vary from palest yellow ("81C") to deepest amber ("85B"). A photographer chooses which filter to use based on the quality of the ambient light. Colour temperature meters can read the temperature of the existing lighting conditions and guide the selection of the filter. Clouded sky, for example, requires a paler amber than clear blue sky. If a filter is unavailable, flash is an alternative