http://www.stevehuffphoto.com/2016/05/02/the-mighty-panasonic-leica-100-400mm-lens-review-by-bob-towery/

http://admiringlight.com/blog/review-panasonic-leica-100-400mm-f4-6-3-dg-vario-elmar-ois/

http://www.optyczne.pl/393.1-Test_obiektywu-Panasonic_Leica_DG_Vario-Elmar_100-400_mm_f_4.0-6.3_ASPH._POWER_O.I.S._Wst%C4%99p.html

The Panasonic 100-400mm ƒ/4-6.3 offers exceptional results for sharpness, providing excellent sharpness when used at its wider focal length, and becoming less sharp as the lens is zoomed in towards 400mm.

http://www.imaging-resource.com/lenses/panasonic/100-400mm-f4-6.3-asph-power-ois-leica-dg-vario-elmar/review/

Does anyone know or could test if the aperture changes smoothly in video recording when using shutter priority (S) in creative video mode. Panasonic says it can:

"The LEICA DG 100-400 performs smooth aperture changes in video to eliminate sudden jumps in exposure"

All my Panasonic lenses makes exposure jumps in video when the lens adjusts aperture in steps. It would be nice to have a stepless aperture for video.

$1349 from HK

http://www.ebay.com/itm/Panasonic-Leica-DG-Vario-Elmar-100-400mm-f-4-6-3-ASPH-POWER-O-I-S-Lens-/112035928225

@Vesku

Buy via intermediary guys, make your own customs declaration and here you go.

https://cyleow.blogspot.com/2016/07/they-shoot-planes-with-panasonic-leica.html

Review

In terms of optical quality, the Leica 100-400mm can be successfully used with the aperture wide-open, capturing sharp details across most of the frame. Like most telephoto zooms, it performs best at the shortest end of the range, but even at 400mm, I was very satisfied with the quality. When compared side-by-side with the Lumix 100-300mm, the Leica 100-400mm generally captured crisper details and higher contrast throughout the range while of course also reaching further.

http://www.cameralabs.com/reviews/Panasonic_Leica_DG_100-400mm_f4-6.3_H-RS100400E/

http://www.promirrorless.it/profoto/leica-dg-vario-elmar-100-400mm-f40-63-asph-ois-la-prova-sul-campo

@Tommyboy - I returned mine for that very reason - everything else about the lens is superb - just annoyingly stiff zoom ring.

@sam_rides_a_mtb Yeah I think I'm going to have to work it hard. I really like the zoom range on it.

http://av.jpn.support.panasonic.com/support/global/cs/dsc/download/fts/index2.html

New firmware v1.1

Improvements

1. Dual I.S.2 function is available. (Firmware update of Dual I.S.2 compatible model is required. The firmware of the DMC-G80/81/85 should be ver.1.2 or later.)
   
2. Fixed the instability of Auto Focus when the focus switch set to [5m - ∞], using Olympus Corporation's OM-D E-M1 MarkII.