This lens has an incredible focus and clarity to it that I love for both Macro and use as a 100mm fixed lens

OK lens for close-up and overall good focus range.

Quiet, fast and accurate auto focus, like you would expect from an L Canon lens.

I shot a picture yesterday of a flower with an ant on it, got the petals in perfect focus and got the ant completely blurred

I actually bought this lens more of a portrait lens, which are often shot soft-focus, but that is not my preference.

It's a macro, so focus is obviously slow as compared to a regular lens

Great focus, clear details, good color

My only complains are it's high price and somewhat slow focusing (but who's using the AF on macro anyways?)

The one area it is not effective w/ macro though is if you rock forward and backward while taking your handheld shot as the IS cannot accommodate for the image losing focus - for that you'd need to use Liveview constant autofocus

This lens is super sharp and much faster focusing then the previous version too.

The aforementioned Image Stabilization is very effective in situations where you can't use the tripod, but want to maintain critical focus while working with shallow depth of field.

(I am waiting for Canon's next full size sensor camera, since the 5D seems to suffer from slow focusing, and I can manage with my 40D for a while)

The large size of the focus ring (relative to lens axis) combined with the fine gearing of the focus mechanism makes manual focusing efficient and precise.

The auto focus, well, it is awful

The wide focus ring is great - manual focus is almost a must for macro

But because focus is so critical to effective macro photography, I thought I'd add this little bit of advice for people who, like me, wear glasses with progressive lenses.

A real joy to use, the rich colors, quiet IS performance, clarity and fast focus makes me realize I just made a great investment, and I don't think the price will ever go down on this lens

I am also impressed with the optical performance as well as its quiet focus and stabilization process.

Crisp, clear, quick focus (and we have a fast moving toddler)!

It's basically there to help speed the AF in finding its optimal focus depending on which camera-to-subject distance you are shooting with - anywhere from strictly close up (.3 to .5 meter of distance) to full range.

As with other Macros, the focus is precise, but moves slower than a standard telephoto lens of the same focal length

Fast focusing and sharp pictures

Beautiful images, beautiful bokeh, tack sharp, quick focus, fairly light with a nice image stabilization feature.

Great glass, fast sharp focus.

It is very heavy and sharp, and the only downside (besides cost) is the focus can be a bit slow when moving between close and far subjects.

It is true, the lens focusing is a bit slow, but the overall performance more than compensates for that

Great construction, fast and accurate focus, great image quality

The camera works well with this lens and gets perfect focus 99% of the time

Also featured is the always-useful full-time manual focusing, giving you that extra level of control over focusing.

It would be in perfect focus for about half a second then drifts off.

I do notice the focus is a little slow on occasion , but this is soon fixed by re focusing on something else.

Nice and sharp, great macro focusing range.

Great focus and beautiful bokeh

extremely sharp, fast focus and smooth ring makes it one of the best lens for portrait and macro photography.

Fast Focus

One word of caution, the depth of focus can be so narrow when the aperature is wide open that even taking a photo of a 1/4" bug will cause half its body to be in very sharp focus while the other half is well out of focus, this lens is really sensitive.

However most real macro work is done with manual focus and the focusing ring is large, easy to grip and has enough movement for very accurate focusing

The focus can be adjusted from macro to non-macro mode, which makes for faster focusing depending on what you need at the moment

Not the fastest focusing lens I have, in low light situations

The auto focus includes a switch that locks out certain focus distances to eliminate unnecessary focus hunting and to improve focus speed (options include full range, 0.3m-0.5m, and 0.5m to infinity).

I did read about the slow focus and low light issues but as long as the object/subject was somewhat lit it focus without an issue.

I've found that stacking with this very precise focus gives me far sharper pictures, even on object I thought didn't need it.

The Focus-Limiter (a manual switch) helps limit the focus-hunt, but only if you remember to set it to the correct range, and even then it's pretty slow when focus-hunting

The aforementioned Image Stabilization is very effective in situations where you can't use the tripod, but want to maintain critical focus while working with shallow depth of field.

The focus range limit switches help shorten focus times on close up subject, though manual focus is still best for extreme close up photography.

Super quiet focusing

Manual focus will be better for stills subjects

Fabulous macro images, Love the auto focus and the IS.

I have shot - HAND HELD - close ups of flowers, bees, mating flies, and butterflies that fill the frame and are in perfect focus with depth of field that reveals the details you hope to get in your shot.

The sharp focus just can't be beat, and even when the IS mode in use, the lens is quick and quiet

I'm extremely happy with this lens, fast focus, great bokeh and color, extremely sharp, and of course the IS.

This lens is only for still objects because the focus is just not accurate.

Must be patient and understand that some MF is needed at times to get the precise focus

I use Canon Mark II, which doesn't have the best focusing.

But, just as a MACRO lens should be, the focus is very sensitive and changes quickly with just the slightest turn of the focus ring.

There is a switch to limit focus, but it still has to hunt to find focus, even center focused objects

I had consistent focusing issues until I finally did some research and microcalibration.

The focus is super fast

I am not a pro but this lens brought me exciting pictures, I was debating between the 60mm macro and this, boy am I glad I paid the extra and got this one. sharp pictures, fast focusing, This only thing I need to point out is: This is a L lens but it is not as heavy as other L lenses

Canon's other lens is manual focus, but since auto-focus struggles with this lens, this might as well be manual focus

Hey, maybe losing my vision will actually improve my photography!So, back to the lens: it's fabulous, but you'll enjoy it even more if you can get the precise focus it allows.

I was amazed at how easy was to work with it, how quiet and fast the focus is and of course, how sharp it is

It's tack sharp, lightweight, compact and holds focus very well

Auto focus is silent and quite snappy for regular subject, for macro/close-up, it is harder to lock correct focus

It gives beautiful focused shots and depth of field where you want it to show up.

After a couple of months of shooting with it, however, the manual focus is no longer an issue and I have been thrilled with the images I've gotten with it.

It is very light weight, extremely fast and quiet focusing

Very crisp photos and very fast focusing

I can never be sure just by squinting through the view-finder whether I achieved perfect focus, so for me it would be great if Canon can improve its auto-focus more