This question is often asked when guests inquire for safaris in South Africa and there is no standard answer to it. It depends what you would like to see and experience.
Wildlife sightings and therefore wildlife photography is the easiest in winter, which is June, July and August. It is not raining in winter and the bush is dry. The animals gather around waterholes and that makes it easier to find them. Also the grass is low in winter and the animals can be easier seen and photographed. The colors are earthy colors with beautiful brown and red tints. But there is a little but; it is cold in the morning and evening with comforting warm temperatures during the day.
Summer is the lush time of the year with high temperatures and all rich green colors. The grass is high and there is plenty of water. It is more difficult to find the animals and also to see them in the grass, but it is so lovely green. Especially when planning a winter escape, the South African summer is ideal. For the photography summer offers just different photo opportunities. The colors are bright and the light is often softer.