I know a lot of people on this forum have lenses I have never tried, so I am looking for your personal use experiences. This question came up last night because I received the EF 100mm Macro L IS. I took some test photos, low light, hand held vs. tripod, some with flash and with apertures ranging from 2.8 to 22. I had taken a portrait shot of our dog and when I enlarged it in (in LR4) to view her eye, my bf was astounded by the detail and sharpness. He questioned what a comparison to the 24-105L would produce. I haven't had a chance to make that comparison yet, but I knew other members here would know what lenses would give the sharpest photos. Any input appreciated as we are upgrading lenses this year. Thank you.