I was eyeing a 70-200 for school events, in particular F2.8 stabilized, and it was between these two lenses. I got a nice deal from a member here, so I grabbed the tamron.
Test charts.... well they're available at multiple places, but you wont see them in this thread. Most of this test is at 200mm, since the other focal lengths were too close in quality, I didnt think it was worth it to spend time there. 200mm is the tamron's weakest spot.
I've read it not being a true 200mm....... well that does have some merit, but not completely. When shooting indoors, really close, the tamron 70-200 will be wider at the BOTH ends, 70 and 200mm. It behaves like a 65-185mm lens. However shooting outdoors, it starts to work itself back to being a 70-200mm lens. At around 30 feet, it's about 195mm, and 60ft+ it's 200mm.
lastly, a flare test and starbursts from 8 blade vs 9 blade aperture blades; no bokeh test performed, they were simply too close to be bothered with. no way to the corners testing either, not going to bother, as the 100% crops are off center anyhow.
Anyhow, TL/DR, here are the comparisons
Full image, subject distance 8-10 ft. You can see the canon is clearly more magnified.
100% crop of the same image
IMAGE LINK: https://flic.kr/p/nNoYTb 100 percent crop by charlie617, on Flickr
same distance at 70mm, Canon is more magnified/ Tamron wider
IMAGE LINK: https://flic.kr/p/o5Agjv Full image by charlie617, on Flickr
Full image, subject distance 30 ft. The tamron behaves like a 195mm lens at this point, almost exact same magnification as the canon, very slightest bit wider.
IMAGE LINK: https://flic.kr/p/o5AgiP Full image by charlie617, on Flickr
IMAGE LINK: https://flic.kr/p/o5AghB 100 percent crop by charlie617, on Flickr
Lastly, the starburst / flare test. Minor crop was done to illustrate flare.
IMAGE LINK: https://flic.kr/p/o5Ampk Minor crop by charlie617, on Flickr
bonus test, AF speed and accuracy. Each lens was racked all the way to closest, then AF fired via remote trigger. 5 shots from mfd to target 30 feet away, then 5 shots from infinity to same target. Disclaimer: Due to the nature of this test, lots of room for human error.
100% crop of the test target:
IMAGE LINK: https://flic.kr/p/o7X96v AF Test Target by charlie617, on Flickr
Both lens hit the target at a 100% rate, 0 misses.
Tamron MFD -> 30ft target in hundredths of a second
90, 81, 81, 85, 81
Tamron infinity -> 30ft target in hundredths of a second
79, 84, 87, 72, 58
Canon MFD -> 30ft target in hundredths of a second
60, 72, 68, 66, 94
Canon Infinity -> 30ft target in hundredths of a second
74, 65, 79, 76, 72
Conclusion: Make your own