Paired this lens with Canon 6D. Sitting on on tripod, stopped down for real estate photography, no IS required. Images are sharp. I use OEM software to correct for distortion and lens optimization. I'm very pleased with the purchase. Canon L glass, at this price, recommends itself .

Canon glass with Canon DSLR equals peace of mind about compatibility

F4 not really fast enough in low light situations without IS

Using a test chart, I found the lens to be very sharp across the image at all focal lengths. The included picture is typical of my results and is a small part of the image from a Canon 5D Mark-II.

The lens quickly snaps into focus and produces good closeups at the 40 mm setting.

Fast / accurate auto-focus; Lightweight; Sharp at all focal length

Barrel distortion

I use this lens for shooting abandoned buildings, so I can more get the scope of the place I'm shooting. THe only thing to keep in mind is that this lens is an f4, so there are some speed and low light issues, but if you're using strobes then it's not a problem.

Strong Construction

Poor in Low Light

It is use in 600d

Well worth the money compared to McBain's pricing,!!!

Smooth operation, and a great upgrade for the standard lens provided with the T3I Canon; Great clarity

A little tilt on the vertical structures; but acceptable

I love this lens. Nice color reproduction and fast focusing. Gave me great results in my last outdoor photo shoots!!

Consistent Output; Fast / accurate auto-focus; Nice Bokeh; Strong Construction

I recently switched from Nikon to Canon and this was my first lens purchased for my 5D Mark II. My decision was made after reading several reviews from websites and blogs. I have to tell you they are all right! This lens takes sharp and vibrant pictures. Good bokeh too, though not the best.

Excellent lens, as expected for an L series lens, Very light

Great sharp lens!

This is a great wide angle lens & in my eyes represents better value than the 16-35 for a few reasons:1- it's literally half the cost2- it's a lot lighter3- I don't have a need for f2.8 when shooting landscapes.I really like the images that it produces & the quality of the L glass speaks for itself.