A favourite delicacy of most southern African antelope, a lot of primates and elephants too, are the beautiful flowers of the sausage tree (Kigelia africana) which occurs throughout tropical Africa. Here a Kudu (Tragelaphus strepsiceros) grazes on the flowers which have fallen from the tree. Often there is a symbiotic relationship between primates shaking branches and dislodging flowers in the tree and the animals which graze these flowers off the ground.
Population Trend : Stable; Threat: Least Concern – Source IUCN
(Canon EOS 5D Mk III/ EF100-400mm IS II USM +1.4x III; 1/500 sec; f/4.5; ISO 640; 400mm)
Picture ©2016 Andrew Field – Simply Wild Photography
The World of Lenses
Zoom Lenses, sometimes known as parfocal lenses where they retain focus through the focal range, are probably the most popularly used lenses, being especially prevalent among wildlife photographers. These lenses allow the user to adjust the focal length on the subject, while the image remains in focus (a zoom lens which loses focus during change to the focal length is varifocal). Zoom lenses suffer a loss of image resolution at maximum aperture, mainly at the extremes of their focal ranges.
“Here’s how you can tell if your ‘zoom’ is actually a varifocal. Zoom to maximum focal length and focus on an object manually about 10 feet away. Now zoom back to the shortest focal length. If the viewfinder is still sharp, you have a true zoom. If it’s hopelessly out of focus, it’s a varifocal.”
– Herbert Keppler