DPReview TV: Tamron 70-210mm F4 vs. Canon and Nikon OEM lenses

70-200mm F4 zoom lenses may not get as much attention as their faster F2.8 siblings, but for many photographers these lenses hit the perfect sweet spot of price, performance, and weight. This week, Chris and Jordan go to the Calgary Stampede with pro photographer Kyle Marquardt to shoot the new Tamron 70-210mm F4, available in Canon and Nikon mounts, alongside the Canon and Nikon equivalents. How does the Tamron hold up, and is it a good alternative to the OEM glass? Watch the episode to find ou...