Panasonic Leica DG 10-25mm f/1.7 lens MFT

Introduction

announced Sept 2018 - world 1st f/1.7 zoom lens!
Micro Four Thirds system mount
“Since image quality of each focal length is [as] strictly controlled as prime lenses, this lens can be seen as equivalent to five prime lenses: 20mm, 24mm, 28mm, 35mm, and 50mm,”
a “Holy Grail” lens for Panasonic videographers although it is expensive and somewhat heavy
much heavier, larger and much more expensive than the Panasonic Leica DG 8-18mm f/2.8-4.0 ASPH lens but you get 2-2.5 stops more light and shallower depth of field (DOF), longer focal length, plus the MF clutch and clickless aperture ring.

covers 20-50mm in FF terms - this is a unique and very useful range which is not covered by any full frame lens as most systems have 16-35mm or 24-70mm lenses
weathersealed
click-less aperture ring
1st Panasonic lens to have a MF clutch
extends in zooming but not by much
close focus 0.28m
77mm filter
690g
128mm long
$US1799

https://petapixel.com/2018/09/27/panasonics-leica-10-25mm-f-1-7-to-be-the-first-f-1-7-wide-angle-zoom-lens/ - announcement
https://www.dpreview.com/articles/6726234179/hands-on-with-panasonic-s-10-25mm-f1-7-micro-four-thirds-lens
Richard Wong's review
- minimal CA, coma or distortion, very sharp wide open across the range and into the edges
- sharper corners wide open than the Panasonic 25mm f/1.4 even when the 25mm is stopped down to f/2.8
Youtube review by Gordon Laing
- significant field curvature can make corners out of focus at 10mm and 25mm - the Panasonic Leica DG 8-18mm f/2.8-4.0 ASPH lens is much better in the corners at 10mm but not as good at 18mm, while the Panasonic Leica DG Summilux 25mm f/1.4 ASPH lenses has similar field curvature and once corrected, the corners are not quite as sharp wide open and has more CA than the 10-25mm at 25mm.