This seems like a popular choice. How about this one? Anyone owned or tried it? I know it's manual focus, not an issue for me.
http://www.the-digital-picture.com/R...ns-Review.aspx

I like the 5x. I think that would make some great polyp pictures.

It is very, very hard to use as it doesn't focus to infinity. The working distance is something like 30 cm at 1:1 and 4 cm at 1:5. I would read up on it before buying, it isn't really for taking pics of anything alive.

I played around with one at the camera store for nearly an hour and focusing on a tripod with a focusing rail took 1 to 2 minutes per shot. That is with pro help as well. Very capable lens but for very specific uses.

I don't use canon but pretty much all my macros are shot with the 150mm 2.8 Sigma. I like the added distance I get with 150mm compared to a 100mm.

I think when one is spending a lot of money on lenses, they should really be as useful as possible.

The Canon EF 100mm f/2.8 is also a great lens for portraiture.

If the budget can be stretched, the IS USM is a much better choice than the USM. I pretty much have to use a tripod with my lens: being that it doesn't have the image stabilization.

Yes the IS model has better optics and is sharper.

But why would you ever need IS on this lens? When will you be taking macro shots below 1/100 or 1/160 (on crop body)?

I can't hold the camera steady enough to use my macro lens without a tripod. 90% of my freehand photos come out blurry. I do sometimes take the camera with me while fishing, and I don't want to drag a tripod along: in addition to all of my fly gear and the camera.

But when you're shooting outside your shutter should be higher than 1/100s meaning camera shake wouldn't cause any blur.

Not when I'm tucked away in an eddy, in the shade, along the Bow, trying to get a photo of trout scales.

Edit: I should add, I'm lucky if my shutter is 1/60 in most of the conditions I shoot in.

You don't need a $1000 lens to get good macro shots pictures.
here is Canon's Canon EF 100mm f/2.8 USM (i don't know if they took that pic with that lens but looks good) http://www.the-digital-picture.com/R...ns-Review.aspx

Here is an old Nikon 995
If i zoom in and crop it will be very close to what they got.
http://i22.photobucket.com/albums/b3...sont/Frost.jpg
.
And here is a $200 Canon D10 macro shots.
http://i381.photobucket.com/albums/o...6/IMG_0549.jpg
.
Here is just zoom in and crop on the pic above (no editing, just Canon's internal viewer crop & save feature ) i was amazed to see the sparkles. can you imagine what insects see! Its like an Avatar movie out there that we don't even pay attention to. Scroll back up to the original and you will see the sparkles, now that you now what to look for.
http://i381.photobucket.com/albums/o...6/IMG_0547.jpg
.
http://i381.photobucket.com/albums/o...6/IMG_0542.jpg
.
i don't have a zoom & crop on this one but it looks a lot like spider web!
http://i381.photobucket.com/albums/o...6/IMG_0537.jpg
.
http://i381.photobucket.com/albums/o...6/IMG_0543.jpg
.

UV filter on or off for macro shots of coral? Thank you.