For Tamron speaks:
+ Image Stabilizer
+ Dramatically lower price
+ Extended warranty
Neutral (applies to both to):
+ Built mechanically very solid
+ Pleasant luminous intensity for a standard zoom
+ Knackscharf
+ Contemporary faster, more accurate and reliable pleasantly quiet autofocus
Against the Tamron speaks:
- Visually in comparative tests a tiny bit worse than the Canon (but practically equal)
- VC on Low battery from secretly, rather than lenses from Canon (see comments)
- No in-camera image correction of Canon in foreign manufacturers of lenses!
Pre - I had my current Canon EF 24-70mm f / 2.8L II USM Standard Zoom Lens (82mm filter thread) black with the Canon EOS 5D Mark III Digital SLR Camera (22 megapixels, CMOS sensor, 8.1 cm (3.2 inch) display, DIGIC 5+ processor was) bought housing black and certainly not unhappy with it. It is from the L-series, knackscharf, robust and we just also benefited from the in-camera corrections thanks storable in-camera correction data for distortion and vignetting. After a while I practice but quickly switched to RAW, which in-camera correction dramatically less important and since then also saw the competition suddenly clearly balanced out.
For photos, there will in future be more bright fixed focal lengths, may then again L-series of Canon. For video again the Tamron this is currently the only 24-70mm f / 2.8 up to while not dramatic, but still very useful image stabilizer. The stabilizer of my Canon EF 35mm lens 1: 2 IS USM (67mm filter thread) black ironed purely from the feeling though more away and nailed the image firmly and clearly, but helpful the Image Stabilizer of the Tamron is quite. Even for photos proved the stabilizer in the absence of light but recently as indispensable. Without some night scene would have been simply scrap and more than maximum aperture f / 2.8, together with absurd high ISO values not going too sometimes the more expensive Canon unfortunately. But switched permanently should not be the stabilizer. No theme for video, but photos can easily be counterproductive and it costs just too plain and simple battery life and produced at worst pictures that would have been better without stabilizer, because the activated control loop in some situations just brings craw unnecessary blurring with itself ,
Tamron is solely for the correction data available only for Canon, camera internal certainly not for everyone the perfect answer, but after I now have the direct comparison of the Tamron against the L-series, remains for me the bottom line is precisely the thickness plus an image stabilizer in otherwise quite coequal facilities and a significant price difference remains.
Conclusion:
Who can do without in-camera corrections and a red ring, gets for about half the price a in my opinion quite equal rank, solid, fast standard zoom and a bonus even the otherwise currently (as of January 2015) anywhere with a 24-70mm f / 2.8 available Image Stabilizer. For me it was reason enough to black me the Canon EF 24-70mm f / 2.8L II USM Standard Zoom Lens (82mm filter thread) in favor of the Canon EF 85mm 1: 1.2 L II USM to separate lens (72mm filter thread) because at this zoom has very clear requirements for my bottom line Tamron ahead and certainly does not need the SP for super performance to hide behind an L from Canon. Processing and performance surprised me pleasantly indeed. It may be that Canon has rare quality problems, but also from Tamron may expect outstanding quality in the SP series and why then obviously defective lenses are not simply returned to service, I am not quite clear. After all - with a 5 year warranty is a at least enough time initially not recognized as such, but to complain about any defects.
