The distance scale is windowed and recessed, offering distance information in feet and meters, as well as the magnification rating offered at a given range. The aperture is made up of eight aperture blades.
While the lens uses a fair bit of plastic construction the mount is metal, and it's heavy enough to suggest that the structure of the lens is metal as well. The lens shows a textured matte black finish, with plenty of room allocated to the focus ring and a distance scale. While the lens is not part of Canon's L-series, it's still built very well, weighing in at 600 grams (just over 1.3 pounds). With a minimum close-focusing distance of 31cm (just over one foot), there's much less risk of shadowing the subject with the camera or your body, and if bugs are your game, you're a bit less likely to scare them off.
#Canon macro 100mm focus line full#
Offering a full 1:1 (100%) macro reproduction is the chief function of this lens. Autofocus results can be overridden by simply turning the focus ring, and the front element doesn't rotate while focusing. It's not as fast as some of Canon's L-class lenses, but then, that's one of the things that makes them more expensive. With Canon's USM specification, the lens autofocuses quickly and quietly, taking about 1.25 seconds to focus from infinity to closest-focus. This distortion is easily correctable in post-processing software, if your straight lines must be absolutely straight. On the full-frame 5D, it's only slightly more significant, showing +0.2% barrel distortion in the corners. Light falloff improves as the lens is stopped down a third of a stop at ƒ/4, and less than a quarter-stop at ƒ/5.6 and smaller.ĭistortion is negligible when the lens is mounted on the sub-frame 20D. At ƒ/2.8, the corners are over three-quarters of a stop darker than the center. In this case, the corners are a quarter-stop darker than the center or, not very much. If you're peeping very closely, you'll see a slight increase in CA at the smaller end of the aperture spectrum (ƒ/32) but it's only very slight.Ĭorner shading is minimal on the 20D, the only noteworthy result found with the lens set to ƒ/2.8. Even ƒ/16 and ƒ/22 are very good, but I'd avoid ƒ/32.Ĭhromatic aberration is well-controlled with this lens, at every aperture setting, on either the 20D or the 5D. In summary, excellent results for sharpness, provided you stick to between ƒ/5.6 and ƒ/11 for maximum performance. Again, fully-stopped down we note significant softness - just shy of 4 blur units across the frame.
It's about the same at ƒ/16, not showing any real loss of sharpness until ƒ/22, where results are just over 2 blur units. This is me being extremely picky - 1.5 blur units is still extremely sharp.ĭiffraction limiting sets in at ƒ/11, where we not approximately 1.5 blur units across the frame, and performance degrades only very slightly from there. The central area of the frame is sharp, easily 1 blur unit, but the corners don't fall below 1.5 blur units. Stopping down to ƒ/4 improves these results, and again by ƒ/5.6, it's as good as the lens can deliver, but not quite tack-sharp across the frame. Corner sharpness at ƒ/2.8 is around 2 blur units, still quite good. Wide open at ƒ/2.8, we still see the sharp sweet spot, but the area of sharpness isn't as generous, covering only about the central third of the frame at 1.5 blur units. On the full-frame 5D, performance is equally good, though we see a bit more of the corners of the lens that aren't exposed on the sub-frame sensor of the 20D. At ƒ/22 it's a bit more obvious - 2.5 blur units across the frame - and fully stopped down at ƒ/32, things are quite soft, 4 blur units across the frame. The lens continues to be sharp all the way to ƒ/16, where diffraction limiting has set in, though even here we note sharpness results of 1.5 blur units across the frame. Stopping down only improves these results, reaching absolute tack-sharpness at ƒ/5.6. At this aperture setting there is a generous sweet spot of sharpness, showing at less than 1.5 blur units, with corners approaching but not reaching 2 blur units. Mounted on the Canon 20D, the lens is very sharp, even wide open at ƒ/2.8. The compatible lens hood, the ET-67, is a circular-shaped hood that does not ship with the lens, available separately for $55. While an upgraded version of the 100mm ƒ/2.8 macro has been launched, this version continues to fill store shelves, with an approximate price of $600. When mounted to the former, the effective field of view is 160mm. The EF 100mm ƒ/2.8 Macro USM was designed to cover a 35mm film frame, making it compatible with both APS-C subframe and full-frame digital camera bodies.
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