Today I set out to test and compare in as unbiased a manner possible the four main 70-20mm options that carry a maximum aperture of f2.8. I used my Canon 70-200 f4L as a baseline for image comparison. The other lenses are:
Canon 70-200mm f/2.8 L
Tamron 70-200 f/2.8 SP Di VC USD
Sigma 70-200 f/2.8 EX DG APO OS HSM
Canon 70-200mm f/2.8 L IS II
They are all sized and weigh in at approximately the same specifications. The Canon IS II and the Sigma offer 2 modes of Image Stabilization, one axis for panning and two axis for holding the camera still, the Tamron allows IS to be ON or OFF. The AF of the Tamron felt the quickest, the AF of the Sigma felt the slowest when manually pulled to infinity, then set focused on an object about 2M from the camera. All have full time manual focus override. All come with a tripod collar, the Canon's and the Sigma come with a nylon and foam padded case, the Tamron does not. All felt like they had a solid build, however the Tamron had a slightly less refined cut on the zoom and focus rings. The Tamron had a Nikon layout for rotation of the zoom ring, the rest felt at home to this Canon user, though both the Sigma and Tamron have the fat zoom ring at the far end of the barrel, where the Canon's have their focus ring and the non-Canon lenses had narrow focus rings. As expected at this level, all have solid metal mounting points for the camera connection.
Now for the test images from inside the camera store, and I remind you the 70-200 f4L is being used to set this as a baseline for the images.
70mm @ f4
200mm @ f4
Now the Sigma 70-200 EX DG APO OS HSM:
70mm @ f 2.8
200mm @ 2.8
Now the Tamron 70-200 2.8 SP Di VC USD:
70mm @ 2.8
200mm @ 2.8
Canon 70-200mm 2.8L
70mm @ 2.8
200mm @ 2.8
And lastly the Canon 70-200 2.8L IS II
70mm @ 2.8
200mm @ 2.8
Now at this point, the images do not appear to be drastically different, and the price difference of nearly $700 across the range seems odd. On the back of the 7D there was very little difference amongst the images.
So I also decided to compare the 100% crop images, as I do make large prints often and want my work to be of the quality that a large print can come under close inspection and still perform.
In Order the 70-200 f4, Sigma, Tamron, 2.8L, 2.8L IS II 100% cops of the 70mm images
Here I think the Canon selections really start to show the quality of the glass as they produce a sharper image across the frame.
Here's a gallery with all of the images included so you can "pixel peep" and get a closer look at the images. I did include a few to help show the Bokeh quality of the lenses. http://drewcanavanphotography.zenfolio.com/p282445426
The Sigma and Tamrons are quality lenses for most applications, however if you're going to go into larger prints I see the Canon lenses really paying off. I could tell when the image stabilization was on vs off, and it seemed to have the most effect with the Canon. At such a price gap between the non-IS and IS II models....I'm not sure that the price gap is justified between the lenses.