I just spent 4 days in Mahale National Park on the shore of Lake Tanganyika on the western border of Tanzania. It is a huge, mountainous, mostly densely forested park with more than 600 resident chimpanzees. One troop of about 60 chimps has been habituated to people.
Visitors in groups of 6 or less are allowed one hour of close proximity to the chimps to observe and photograph them. You are escorted there by a guide and watched over by a national park ranger and you must wear a surgical mask and always give way to the chimps.
The experience is both wonderful and exhausting- hiking up a mountain side in a hot tropical rainforest will do that. But the rewards are great, bordering on magical. To stand or sit quietly watching the chimps go about their business without any heed to you is astonishing. Little babies swinging on vines or climbing on limbs, adults sitting in a tight circle grooming each other, mothers nursing, juveniles rough housing. And all of it so close I had to keep zooming back to get it all.
Not every photo was a success. I took lots of pics that were out of focus (slow shutter speed from low light) or that had faces hidden. And I accidentally cut off a lot of chimp hands and feet- their arms are astonishingly long. I had to use the center autofocus point if I wanted to get the entire chimp in the picture. But after each morning shoot was done I ended up with a dozen or so strong shots and a head full of memories. Sounds like a perfect time.