There is something of The Wizard of Oz about Marina Amaral’s photographs. She whisks us from black-and-white Kansas to shimmering Technicolor Oz. When Howard Carter leans over Tutankhamun’s open sarcophagus (1922), he does so in the glare of pharaonic gold. A photograph of fallen American soldiers on the Gettysburg battlefield (1863) shocks the more when we see the colour of the blood soaking through shirts.