11-24-2020, 02:12 PM
Btw, it has RXD in the name, not RX D. RXD is Tamron's new motor style, like Canon's STM and Nikon's stepping motors (AF-P for DSLR lenses, no naming in the Z lenses (STM in their "specs"), as seen in the Tamron 28-75mm f2.8 Di III RXD.
Also, Tamron made quite a mess of their naming convention with "Di III". In the past, Di meant full frame SLR lens with better coatings for digital cameras, to prevent purple fringing. The later Di II naming signified that the lens had a smaller APS-C image circle. Then again a bit later Di III meant lens for mirrorless micro 4/3rds cameras. Then came the big mess, where Di III just meant "for mirrorless camera", whether the lens was for FF mirrorless Sony or for MFT. Now they added an "A" (Di III-A) to make clear it is for APS-C.
Also, Tamron made quite a mess of their naming convention with "Di III". In the past, Di meant full frame SLR lens with better coatings for digital cameras, to prevent purple fringing. The later Di II naming signified that the lens had a smaller APS-C image circle. Then again a bit later Di III meant lens for mirrorless micro 4/3rds cameras. Then came the big mess, where Di III just meant "for mirrorless camera", whether the lens was for FF mirrorless Sony or for MFT. Now they added an "A" (Di III-A) to make clear it is for APS-C.