Canon, Sigma and Tamron 70-200 f/2.8 lenses (and 100-400)

Sigma 70-200 2.8 EX HSM, Tamron 70-200 2.8, Canon 70-200 2.8 IS USM. Click here to enlarge.
 
The 70-200 f/2.8 zooms are good lenses for sport and portrait photos; for nature photography, 200mm usually is a bit too short: nevertheless, I was curious to see how the Tamron and Sigma 70-200 2.8 performs in comparison with the much, much more expensive Canon 70-200 IS. Other than that, I wanted to compare these lenses with one of my favorite Canon zooms - the 100-400 IS - too see the difference between the versatile canon lens and the 70-200 zooms with 1.4x and 2.0x teleconverters.
 
 

Specifications

 
 

Built quality, stabilization and autofocus

The Canon 70-200 2.8 has the best built quality; it has a professional, solid look, and it is weather sealed. The Sigma and the Tamron are similar; they are good, but not as good as the Canon. The Tamron has a better painting than the Sigma that scratches very easily as all Sigma EX lenses; on the other hand, the zoom ring and the focus ring of the sigma feels more solid, while the rings of the Tamron are a bit too smooth. In particular, if you use manual focus the Sigma and the Canon allows to focus with more precision, while with the Tamron it is enough to rotate slightly the focus ring to move a lot the focus point.

Sigma 70-200 2.8 EX HSM, Tamron 70-200 2.8, Canon 70-200 2.8 IS USM (with hood). Click here to enlarge.
 
All three lenses offers good AF speed, but the Canon is clearly the best in this respect, it is really fast! The Sigma and the Tamron have a slightly slower autofocus (the Tamron lacks of ultrasonic motor, so the AF is slower and noisier). An advantage of the Sigma and the Canon is the possibility to focus manually even during AF, thanks to the ultrasonic AF motor, while with the Tamron it is not possible. The Canon is the only 70-200 of the group that offers image stabilization. This is another big advantage for the Canon; IS helps a lot when handholding the lens.
 
 

Image quality comparison

I have tested the lenses on my Canon 1DsIII (21 megapixel, FF). The lenses was mounted on tripod; I have used mirror lock up and self timer. The following images are 100% crop from the unprocessed RAW file. (note: c70 is Canon 70-200 IS, s70 is Sigma 70-200, t70 is Tamron 70-200 and c100 is Canon 100-400 IS). All lenses had been tested both wide open and stopped down by one stop.  
 
For the 70mm focal lenght, I have used a different test target than the one used for 200, 280 and 400mm, because at 70mm is was not possible to fill the frame with the small test target used for the longer focal lenghts.  
 
 
 
70mm, center:

 
 
 
 
70mm, corner:

At 70mm, all tree lenses gives identical image quality in the center, excellent sharpness both wide open and at f/4. In the corners, instead, the Tamron is the sharpest; the Canon is very close, while the Sigma is softer.  
 
 
 
200mm, center:

 
 
 
 
200mm, corner:

At 200mm, all 70-200 shows similar image quality in the center; they are ok at f/2.8 and good at f/4. The 100-400 has a little more contrast and sharpness, but its maximum aperture at 200mm is just f/5.0. In the corners, it is a completely different story. The Canon and the Tamron produces nearly identical image quality; the Sigma has more chromatic aberration and it is the softest, while the Canon 100-400 has much better image quality than all three 70-200.  
 
 
 
280mm (70-200 + 1.4 TC), center:

 
 
 
 
280mm (70-200 + 1.4 TC), corner:

In the center at 280mm, the three 70-200 2.8 give similar results, both wide open and at f/5.6 (the Tamron is a little sharper at f/5.6, but it is not a big difference). The 100-400 is much shaper than all three 70-200.  
 
In the corners, the Tamron 70-200, Canon 70-200 and Canon 100-400 are similar (the Tamron is an hair sharper), even though the 100-400 has much less chromatic aberration the the 70-200 zoom. The corners are the Achille's heel of Sigma 70-200: it is much softer and it has more chromatic aberration than the other lenses.  
 
 
 
400mm (70-200 + 2.0x TC), center:

 
 
 
 
400mm (70-200 + 2.0x TC), corner:

At 400mm in the center, all 70-200 2.8 zooms give poor image quality wide open; the Canon 100-400 is way better. At f/8, all lenses show an improvement, but the Sigma 70-200 and the Canon 70-200 are still quite poor; the Canon 100-400 is miles ahead. Surprisingly, the Tamron 70-200 at f/8 comes close to the Canon 100-400, and it is much better than the other two 70-200 (while wide open there wasn't much difference between the three 70-200). In the corner, the 100-400 is once again the clear winner. The Tamron is the sharpest of the 70-200 zooms, while the Canon and the Sigma are very poor in the corners.
 
 

Conclusions

The results of this test are interesting, but they are in line with my expectations, at least for the 100-400 vs 70-200 comparison. The 70-200 lenses are not a good choice if you need reach; indeed, the Canon 100-400 offers much better image quality than every 70-200 + 1.4x or 70-200 + 2x. Even the expensive Canon 70-200 2.8 is much worse than 100-400, at 400mm. If you don't plan to use a lot the 2.8 aperture, I'd recomment to buy the 100-400 - it is a much better lens for nature photography.  
 
If you want a 70-200 2.8, instead, the choice depens by the budget and by the sensor size of your camera. In the center, all three 70-200 are quite similar, so on APS-C you won't see image quality differences. If you don't mind the lack of image stabilization, I'd recommend the Sigma, it is much cheaper than the Canon and it has better autofocus than the Tamron. Overall the Canon is the best, but it is way more expensive, so you have to evaluate if it is worth the price depending by your esigencies.  
 
On fullframe cameras, it is a different story. All three lenses are not great in the corners, but while the Canon and the Tamron are close (actually, the Tamron is slightly sharper), the Sigma is really soft in the corners. On FF, I recommend the Canon (if you have high budget) or the Tamron, that is an extraordinary lens for its price, in terms of image quality.