I own the Sigma 70-200 FLD OS and have had the Tamron, the tammy is good but just not in the same league as the Sigma FLD. The only plus the Tammy offers against the Sigma FLD is price, something like $5~600 cheaper, for the extra money you get incredible image quality plus:
- Quick Shift Focus (Huge, Huge, Really Huge Plus)
- Electronic AF/MF switching right from the lens with no need to switch the body (Also huge if you are an old MF shooter like me as this allows for CIF to be used)
- HSM silent focusing (Also extremely fast focusing)
- Some of the best CA control from any lens manufacturer (Due to the FLD coatings)
For TC's, any TC with power connections for HSM/SDM/USM will work with the Sigma.
So, the bottom line:
Originally posted by tammons What is the sharpest 70-200mm CA free AF lens for the money ??
For the money, maybe the Tamron fits the bill a little better for you if you can do without the extra features.