f4-5

canon, 500mm, sigma, 4, 500, nikon, 3, 6, +, is, reserve, wildlife, big, desert, safaris, botswana, safari, five, delta, game, 1, vr, ef, usm, l, wild, panthera, feline, photography, iso, f, 400, 5, 600mm, nikkor, mm, marsh, 2, f4, hsm, savuti, national, chobe-nationalpark, eos, savute, lodge, channel, chobe, takumar, park, g, 400mm