I had the pleasure of using two of these lenses, albeit pre-production, with two Lumix S1R bodies while on my trip to Tanzania. I used these with and without the 1.4X and 2X teleconverters in order to extend the reach as needed. With the high resolution of the S1R cropping is a viable option.
The Pro S 70-200 has one of the best image quality performance I have seen in a zoom lens in the range. The lens surely must meet or exceed certain stringent standards to be certified by Leica.
Tech details: 22 elements in 17 groups, the use of 2 UED (Ultra Extra-low Dispersion) lenses, 3 ED (Extra-low Dispersion) lenses. Magnification .21X with a close focus distance of .95m. Focus range switchable from Full to .95m-5m and 5m to Limit. The lens is 208.6mm (8.2 in) long with a max diameter of 94.4 mm (3.72 in)and weighs 1,570 gm (3.46 lb). Filter diameter 82mm. It is dust and splash resistant and has a working temperature range of -10 C to 40 C (14 F to 104 F). The focus speed is rated at 0.12 sec. at the extended focal length of 200 mm. It has a focus clutch to allow manual – autofocus switching and the lens barrel has three programmable focus buttons. Dual IS – when coupled with a Dual IS2 body the overall image stabilization is rated at 7 stops. The provided lens collar has an Arca Swiss compatible foot.
I found that the lens had exceptional focusing speed and now understand why. The lens uses a double focus system. A large linear motor is used for long-throw adjustments and a stepper motor is used for small incremental strokes. All focusing is internal and the focusing lenses are light so as to allow rapid movement during focusing. The focus frame rate is 480 FPS and the lens tracks subjects incredibly well. This combination clearly has the fastest focusing I have experienced in the Lumix lens line-up. The close focus distance is .95m or about 3 feet. Even at this close range, there is no visible distortion. in-fact the has little to no distortion over its entire zoom range even wide open at f/2.8.
For the duration of the Tanzania safari, I never mounted either S1R on a tripod or any other clamp or mount. All images were captured hand-held and the image stabilization was amazing even at slow shutter speeds.
Note: Some images have been cropped and some have a vignette applied for presentation purposes.