Tamron EF 100-400mm Lens Review
Price vs performance
Well built metal lens
Sharp at all focal lengths
Compatible with Tamron Tap in console for firmware upgrades and adjustment to lens
Decent VC / IS (vibration compensation / image stabilization)
Things to keep in mind
If you want the ultimate lens in this focal length, the Canon EF 100-400mm or RF 100-500mm are the ones to get though at a significant premium price and a slight increase in weight
Future compatibility with mirrorless camera models
I had to adjust the VC to shutter priority, and the Limiter switch to 8 feet to one notch below infinity otherwise lens was hunting a lot. This is mainly with mirrorless camera. With DSLR it behaves well.
I had to switch-off in camera corrections such as DLO, peripheral illumination, CA, etc. Even in C-raw file, there seems to be loss of fine resolution when these in camera corrections are switched-on. Observed this on both cameras I own i.e. EOS-M6 and EOS RP) . This is mainly with mirrorless camera. With DSLR it behaves well.
Using my default Canon RAW editor DPP4 wouldn't bring out as much resolution in fine details. I guess due to missing DLO. DXO Photolab 4 did an excellent job to bring the fine details