Dave Dugdale from Learning DSLR Video previously carried out a number of different comparisons Nikon D800 and Canon 5D Mark III, now when he chose Canon is time to look for a good lens. He wants select the best 24-70mm f2.8 lens from among three candidates:
- Canon 24-70mm lens: Filter Thread 77 mm , 953 g, 12.19 cm length $1,600
- Tamron 24-70 VC lens: Filter Thread 82 mm, 825 g , 11.68 cm length $1,300
- Sigma 24-70mm lens: Filter Thread 82 mm, 790 g, 9.40 cm length $900
At first sight the best for video shooting is the Tamron lens features vibration control (VC):
"I think a lot of people that shoot video are frustrated that Canon didn’t give us a 24-70 with IS. I think Cannon lost an opportunity here and has left the door open for Tamron on this one" - Dave notes.

But the most important factor in this comparison addition to the functionality is sharpness. The principles for assessment as he applied in comparisons, Dave defines as follow:
"If there was an instance where in one test there was one lens sharper in the center but the other was sharper in the corner, I gave the win to the one sharpest in the center. When I had to spend more than 30 seconds trying to figure which one was sharpest I would call it a tie, sometimes it was so close."
Check how these lenses passed the all the benchmarks and which one is best.
Key observations about the sharpness Dave has recorded in several points:
- For the most part they all tied in the middle f5.6 to f8 at both wide and tele.
- Sigma did really well at f22 and f2.8 at 24mm.
- The most glaring however was Sigma at 2.8 at 70mm.
- Tamron won only once at f8 at 24mm but it had no glaring issues and way always ever so slightly behind the winners.
- The Tamron VC is a lot quieter than my Canon 28-135 IS.
The extensive description of the comparisons you will find the Dava's blog.


