It shouldn’t come to surprise anyone when I say I love the 100mm focal length on APS-C cameras. What should be an awkward length too long for “typical” portraits (usual range is 85-135 on 35mm camera), but too short for a long telephoto (those start around 180-200mm)–becomes an “up close and personal” portrait lens useful in separating subjects from a crowd, or emphasizing certain features of people. With a stop-and-a-third slower maximum aperture than my 105mm f/1.8 AI-s, the degree of separation on the 100mm f/2.8 E is somewhat less, and the “pop” starts to fade away (shallow depth of field is an aspect of photography I love to employ). Also, in low light and at max aperture, it can be a bummer to still have to either slow the shutter speeds (risking motion blur) to stay at low ISOs, or to raise the ISOs (resulting in more noise) to keep the shutter speed high. When shooting conditions go south, compromises have to be made. So be it.
Regardless, the 100mm f/2.8 E has to have redeeming qualities, right? You bet. I do like this lens very much, for reasons detailed below–so much so, I’m not particularly sure which lens (the 105mm or 100mm E) I enjoy the best overall. There’ll be a section discussing that near the end, but let’s get onto the meat-and-potatoes!