Tamron lenses on Sony E-mount cameras have been held in pretty high regard in recent years due to their outstanding performance for the price. Tamron APS-C lenses for Sony E-mount might end up being an even more attractive option since Sony doesn’t make a lot of high-quality crop lenses. Below is a summary of DPRTV’s findings:
The name is a bit of a mouth full
f/2.8 throughout 17-70mm zoom range (similar to f/4 depth of field on full-frame and about 25.5-105mm)
On the Sony a7RIV, you still get about 26mp in crop mode
Very light and compact
Built similar to other Tamron lenses for E-mount
67mm filter threat which Tamron uses on their E-mount glass
No buttons on the lens so all functions are done through the body
Stepping style motor, but it performs well
Near to far, AF is snappy
Bokeh isn’t bad and remains round with minimal cats eye, but it can be very busy with onion rings etc…
LoCA gives you a cyan magenta split which isn’t terrible, but it is there
There are some flare/ghosting issues
Manual focus is loose with little dampening, but for videographers, there is little breathing on this lens
17mm is very good even out to the corners
70mm is quite acceptable with good results wide open
Sharpness is consistent from wide to telephoto
Using the lens on the a7RIV you’re getting 2MP more than Sony APS-C bodies
Other similar lenses are pretty bad unless you spend big money and even then they aren’t completely comparable