DPRTV posted their Sigma 28-70mm review filmed on the Pentax K-01 so the quality is quite lacking, but it is interesting to see how Jordan gets around the limitations with dubbed audio and more. Below is a summary of their review:
- Very small and compact
- 67mm filter thread
- 474g
- Worlds smallest 28-70mm f/2.8 full-frame lens
- Tamron is basically the same dimentions with 28-75mm of range, but a little bit heavier
- This lens is mostly polycarbonate with a metal lens mount
- The lens is not weather sealed
- Well dampened zoom and manual focus ring
- No OIS
- Little ghosting in the far corner, but impressive all around
- Better at the wide-angle than the telephoto range
- AF is very quick
- Very little breathing at 70mm with a little more at 28mm
- Bokeh has a lot of cats eye in the corners and even towards the center of the frame, but it is otherwise nice
- Bokeh remains round as you stop down, which helps with the cats eyes
- No major chromatic abbreviation, but there is some LoCA
- Barrel distortion at 28mm with pincushion distortion at 70mm
- Sharpness is pretty good in the center at 70mm f/2.8 but gets better by f/5.6
- Corners aren’t very sharp even stopped down at 70mm
- At 28mm the corners are better and the center sharpness is good at f/2.8, but gets better at f/5.6
- This lens is a nice performer stopped down, but wide open it depends
- The problem is the Tamron is a very good lens that is otherwise excellent outside of some distracting bokeh
Sigma 28-70mm F2.8 DG DN Contemporary:
B&H Photo / Amazon / Adorama
Tamron 28-75mm f/2.8 Di III RXD FE:
B&H Photo / Amazon / Adorama
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