One of the things about hunting in Africa is that you shoot what you brought with you for the most part. On a month long Big Four hunt in 2011, I brought a .416 Rigby with an illuminated circle dot reticle Swaro 1.5-6x42 (now sadly out of print) and a .470. Both leopard and lion were on the menu and those shots are often taken in low light conditions. My thinking was that a 42 mm objective lens would gather more light at dusk or dawn than a 20mm objective lens, so that's the Swaro was mounted on the .416.
Perhaps someone with lots of scope knowledge (such as MD) could let us know if that reasoning was correct or if a 1-5 x 20 would have worked just as well in low light.
