Comments about Sigma Sigma 24-70mm f/2.8 EX Aspherical IF EX DG HSM AutoFocus Zoom Lens for Canon EOS Cameras:

I had to send this lens to Sigma 3 times, once with my 5D to get the focus to work accurately. However since its been fixed, it does focus accurately most of the time. Its still a bit iffy if the subject is more than 30 feet away from me, but on the whole, its pretty accurate.

On full frame sensor(5D, 5D II, 1Ds series) the image quality in the center of the frame is truly Canon L quality, however the edges leave a lot to be desired.

On a crop framer(7D) with a little bit of Micro-focus - and since the crop uses the sweet spot of the glass (the center) - the results are seriously tack sharp from edge to edge of the frame... In fact this lens in combination with my 7D is just a stellar mix... I like it more than my EF-S 17-55 and more than my 28-70mm L f/2.8... I can't say the same on my 5D(full frame) - I prefer the Canon 28-70 on the 5D. Which is unfortunate, because the Sigma was made for a full frame camera... It just doesn't shine there...

Bottom line, if you shoot with a crop frame camera surf your browser to the nearest photo web site who sells it and buy it... If you shoot a full frame Canon, think twice and really consider the Canon equivalent - even if it costs hundreds more...

Comments about Sigma Sigma 24-70mm f/2.8 EX Aspherical IF EX DG HSM AutoFocus Zoom Lens for Canon EOS Cameras:

I purchased this lens for an upcoming wedding. But after testing it for a couple of weeks I found that it simply wasn't sharp enough or consistent enough. I have sent it back and have ordered the Canon 34-70.

Comments about Sigma Sigma 24-70mm f/2.8 EX Aspherical IF EX DG HSM AutoFocus Zoom Lens for Canon EOS Cameras:

I received this yesterday just before heading out to a live indoor music event, and it pretty much stayed attached to my 50D for an entire evening of jumping, strumming, and jamming. This is the fourth Sigma lens I have owned, and despite numerous reviews about quality control, each one (especially the 24-70) has had good sharp image results. Maybe I am just lucky, but I have never had a quality issue with a Sigma lens.

As to ruggedness, it is tougher than my nose is after getting slammed by an impromptu mosh pit started in the vicinity of where I was situated, and the blood also wiped off pretty easily (not really).

On the down side, I did discover that autofocus does not work too well in low light...I had to switch over to manual for the majority of the event. This is not really criticism; I doubt any lens would have been able to use AF in the dimly lit corner of the club where I was shooting.

My sharpest shots seemed to occur in the f/5.6 range, although results were still good wide open at f/2.8. I shoot with a cropped sensor (1.6x), so vignetting is not an issue I usually have to deal with. I definitely recommend this Sigma lens to anyone who needs a good, fast intermediate range solution that can not afford the price of a Canon or Nikon equivalent. You should not be disappointed.

Comments about Sigma Sigma 24-70mm f/2.8 EX Aspherical IF EX DG HSM AutoFocus Zoom Lens for Canon EOS Cameras:

I purchased this lens in June 2010 after debating whether buying this or the Canon 24-70mm f/2.8L USM. I had used both lenses before and the Sigma left a more distinct impression in terms of focus speed and sharpness.

Lens focuses extremely fast and has no trouble locking onto the subject, even in low light. Images are consistently sharp, even at f/2.8. It is a heavy lens if you are used to a 18-55mm kit lens but compared to the Canon 24-70mm f/2.8 (nick named "the brick") this lens is light, and features an overall smaller build (but larger front element and filter ring).

Comments about Sigma Sigma 24-70mm f/2.8 EX Aspherical IF EX DG HSM AutoFocus Zoom Lens for Canon EOS Cameras:

Complete waste of money. Had to send it to Sigma to calibrate it to my camera and even after getting it back it is still unable to produce a sharp focus[...] so I am stuck with a $900 lens that is basically useless!