Originally Posted by
Sean Setters
Di - Digitally Integrated Design (to reduce ghosting, flare, CA and peripheral light fall-off along with improved resolution)
And Di-II means that it can be only used with APS-C sensor cameras.
I do a lot of macro work, and recommend the 100/2.8 non-IS. It is (relatively) inexpensive, SHARP, and does almost everything that 100L IS can do. I've never missed IS with it, simply because with macro, it is often necessary to use small apertures to get adequate DOF. With small apertures, light becomes a problem quickly, especially with light loss at such close focusing distances. Thus it is often necessary to use flash or tripod. It is also somewhat difficult to handhold so close and keep your subject in focus, making a tripod even better. Flash also has the advantage of "freezing" your subject, so you can shoot with an active subject where IS would be worthless.
Short story: Spend less on the lens and spend more on lighting and a good tripod and (very) sturdy ballhead.
Also, about the telephotos, I recommend trying both the 300/4L and 100-400L before you buy. They are both excellent.
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