The flight of the African Fish Eagle, releasing 14th June 2013, (Haliaeetus vocifer) miniature sheet for the first time in South Africa shows a moving image on stamps featuring the lenticular technique.
A lenticular is a combination of a special lens and an arrayed image that simulates animation or depth. Autostereoscopic images refer to pictures that take advantage of how our eyes and visual cornea process the two images that the left and right eyes receive. They interpret them as depth and three-dimensionality. A lenticular uses the movement of our bodies in relation to produce a pseudo-hologram that might look like a person running, an apple popping out of a flat poster, or a distant car approaching.
There are two parts to a lenticular. The lenticules, or the series of elongated plastic lenses, focus, magnify, and direct the right parts of the picture to your eyes. The interlaced background image (apart from an overlaid lenticule) looks like a jumble of several pictures. Actually, the assembly is made of stripes of a number of images divided vertically or horizontally that are interlaced such that only one slice of each image lies behind each lenticule.
The various images are revealed in sequence to the viewer as you look at the picture from different angles, such as walking by a poster or tilting a hand-held card. The lenticular controls which slices you see at which angle, such that together you are only seeing one reassembled, whole image at each point in time. Through rapid movement, or with smaller lenticules, the images blur together into depth or motion. Six images were positioned twice in the respective lenses to get the best motion effect on the South African stamps. Six photographs for each stamp, were taken in sequence using a high speed camera by photographer Chris van Rooyen.
The African fish eagle is one of the most widespread birds of prey south of the Sahara. It is the national bird of Zambia and Zimbabwe, while it sits in the Coat of Arms of Namibia, South Sudan and again Zambia. Its scientific name, Haliaeetus vocifer, stems from ancient Greek – halieos meaning fisherman, aetos meaning eagle and vocifer referring to its loud vociferous call.
A very distinctive bird in flight, the white head, neck, upper belly, and tail contrast sharply with the chestnut and black body feathers. The striking adult plumage is only obtained when these birds are four or five years old. Fully grown, males weigh only 2,2 kg on average, compared to the 3,4 kg of females.
The African Fish Eagle is most frequently seen by the rivers, lakes and coasts of Africa south of the Sahara. Near Lake Victoria and the other great lakes of Central Africa it is seen in large numbers most often sitting in tall trees from where it has a good view of the stretch of river, lakeshore or coastline which is its territory.
Fish make up 90% of their diet, while the other 10% consists of young water birds or carrion. They are able to snatch fish weighing 1,5 kg, carrying them off in flight. Anything heavier and weighing up to 3 kg is caught and ‘planed’ across the water onto shore. It takes an average of eight strikes for a successful meal.
African fish eagles are often spotted in mating pairs near fresh water habitats such as rivers, dams, lagoons and even estuaries. Males are extremely vocal at the beginning of the breeding season when they attempt to impress the female. Fish eagles are monogamous and mate for life.
In 2012, the African Fish Eagle was South Africa’s Bird of the Year – an initiative among several started by BirdLife South Africa aimed at creating awareness about birds, their habitat and conservation.
www.capenature.co.za/ • www.sa-venues.com • www.birdlife.org.za