Excerpt: I have had this lens for several years and it is my go to for portraits.it is so sharp, I often find myself softening the pictures to satisfy my clients. great weight to performance ratio ( is that a thing?). I chose it over the 85 becuase of the bokeh being just that little bit nicer...YMMV. excellent build, can't say enough about this glass. Can it really get any better than this? Wish it had an included lens hood..
Pros: Consistent Output, Fast / accurate auto-focus, Nice Bokeh
Excerpt: Did alot of research prior to buying this lens and I'm glad I did. I am very satisfied with it. Great image quality, sharp wide open, good construction, and has a solid feel to it. Not much more I could ask for out of it other than a closer focusing distance.
Pros: Consistent Output, Fast / accurate auto-focus, Nice Bokeh, Sharp
Excerpt: Using this with my 6D, it produces tack sharp images with a fantastic bokeh. Compared to the Canon 85mm 1.8, this lens produces much better images for me. I just don't get the sharpness, colors and bokeh with the 85mm like I do with this. Plus I prefer the 100mm focal length for portraits. The results I'm getting with this really remind me of my Canon 135mm L 2.0, which in my opinion is the greatest Canon prime lens ever made.
Pros: Consistent Output, Durable, Easily Interchangeable, Fast / accurate auto-focus, Nice Bokeh, Rugged, Strong Construction
Excerpt: The 100mm f/2 is really good, a bargain considering the quality. Sharp from wide open in the center but slighty degraded performance wide open due to vignetting/slight corner softness corrected by stopping down, even with lens data correction. Light and good. I shot this against the 135mm f/2, and it's almost as good, but much much lighter, so I've got two kits: lightweight for travel, and heavier for shoots when I don't have to walk all day.
Pros: Consistent Output, Fast / accurate auto-focus, Lightweight
Conclusion: This lens is very well built, it may not be fully sealed but in my opinion that's the only thing stopping this having a red ring. The lens does not move either the front or rear element for focussing which means it is naturally reluctant to attract moisture or dust internally. The proper ring-USM focuses nearly immediately, it's frighteningly sharp even wide open, the Boke and low light ability is lovely thanks to its wide aperture. What would I change?
Pros: Fast auto-focus, Superior build quality, Super-sharp images, wide aperture