Here're some sample images taken with the EOS 5D II and RAW converted via Canon DPP.
Click on a thumbnail to view the original file (opens in a separate window). Please note that the originals are FULL SIZE samples (=several megabytes) thus requiring a significant amount of bandwidth so please take care of the limited resources here.
Make
Canon
Model
Canon EOS 5D Mark II
ISO Speed
200
Focal Length
200.0mm
Aperture:
f/8.0
Exposure
1/400s
Make
Canon
Model
Canon EOS 5D Mark II
ISO Speed
200
Focal Length
238.0mm
Aperture:
f/8.0
Exposure
1/800s
Make
Canon
Model
Canon EOS 5D Mark II
ISO Speed
200
Focal Length
300.0mm
Aperture:
f/5.6
Exposure
1/800s
Make
Canon
Model
Canon EOS 5D Mark II
ISO Speed
200
Focal Length
70.0mm
Aperture:
f/9.0
Exposure
1/400s
Make
Canon
Model
Canon EOS 5D Mark II
ISO Speed
200
Focal Length
191.0mm
Aperture:
f/5.0
Exposure
1/2000s
Make
Canon
Model
Canon EOS 5D Mark II
ISO Speed
200
Focal Length
70.0mm
Aperture:
f/9.0
Exposure
1/500s
Make
Canon
Model
Canon EOS 5D Mark II
ISO Speed
200
Focal Length
300.0mm
Aperture:
f/9.0
Exposure
1/25s
Make
Canon
Model
Canon EOS 5D Mark II
ISO Speed
200
Focal Length
70.0mm
Aperture:
f/11.0
Exposure
1/100s
Make
Canon
Model
Canon EOS 5D Mark II
ISO Speed
200
Focal Length
300.0mm
Aperture:
f/5.6
Exposure
1/250s
Make
Canon
Model
Canon EOS 5D Mark II
ISO Speed
200
Focal Length
300.0mm
Aperture:
f/5.6
Exposure
1/200s
Make
Canon
Model
Canon EOS 5D Mark II
ISO Speed
200
Focal Length
300.0mm
Aperture:
f/5.6
Exposure
1/400s
Make
Canon
Model
Canon EOS 5D Mark II
ISO Speed
200
Focal Length
300.0mm
Aperture:
f/5.6
Exposure
1/500s
Verdict
The Tamron AF 70-300mm f/4-5.6 SP Di VC USD is a very welcome new option in the tele zoom lens class. The lens is capable of delivering a very good to excellent center quality combined with good to very good borders/corners. Lateral CAs are low and not objectionable from a field perspective. A nice aspect is the image contrast which is very high throughout the range including the critical 300mm setting. Based on what we've seen in the field the lens is also comparatively resistant against flare. The light falloff at max. aperture is visible but not higher than on competing lenses. The image distortions are slight (70mm) to moderate (200-300mm). The quality of the bokeh can be rough in critical situations specifically regarding the highlight rendering. This may be somewhat unfortunate but the truth is that this aspect is generally a problem in this lens class.
The build quality is very high for a lens in this price class although it stays somewhat short of truly professional grade lenses. A real progress is Tamron's new USD ("Ultrasonic Silent Drive") - compared to the previous AF micro-motor generations it is both fast and near-silent and it supports FTM (Full-time manual override). Tamron's image stabilizer - it's called VC ("Vibration Control") - works fine although we won't really sign the claimed 4 f-stop efficiency. Either we had too much coffee during the field trip or it's actually closer to 2.5 f-stops.
The question of the day is, of course, whether it can beat or at least match the quality of its direct competitor - the Canon EF 70-300mm f/4-5.6 USM IS. Well, it gives and takes a little. Optically they're very close with slight advantages on either side depending on the specific aspect. However, the Tamron has a certain edge with respect to AF as well as build quality so it represents a slightly better value offer.
to 
