The Panasonic Lumix G Vario 45-200mm f/4.0-5.6 Mega OIS offers an equivalent focal range of 90-400mm, making it an impressive sports and wildlife optic
And bearing in mind that the lens measures only about 13.5cm when fully extended, that is a lot of lens in such a small package.
Even so, some people might say the lens looks a bit too big for a Micro-Four-Thirds body, its diameter being such that the zoom is wider than the height of the camera (in the case of the Olympus PEN Mini used for this review). That may cause a problem with some tripod mounting plates, which could foul the zoom ring, but careful positioning ought to avoid any such difficulties.
The zoom ring is broad and occupies almost all of the rear-half of the lens barrel. The manual-focusing ring is at the front of the lens and remains undisturbed in AF mode. A slider that activates the Optical Image Stabiliser (OIS) is located between the two rings and falls conveniently under the users left thumb.
The lens is very comfortable to hold thanks to the same bulk that makes it look a little too big on such a small-format body. That said, it would be more comfortable to have the zoom ring at the front of the lens, where it would be easier reached, and the focussing ring at the rear. The resistance is about right on both rings.
There are no distance markings on the focusing ring and neither are there any depth-of-field markings on the barrel. A generous lens hood is supplied but this makes the lens even bulkier when reversed for storage. And although it may be a peculiarity of using a Lumix lens on an Olympus body, I couldn’t get the lens to focus manually.
Technical testing produced a set of steep MTF curves that reached an impressive maximum level of resolution (between 0.4 and 0.5 cycles-per-pixel) but with a rapid decline towards smaller aperture settings (larger F-stop denominators).
It would have been nice to have had a bit more consistency but the biggest problem was colour fringing seen at the 200mm end of the zoom range, which is also where the resolution was lowest.
Panasonic has sensibly limited the minimum aperture setting to f/22, by which point the MTF curves for all three focal-lengths tested were below the critical 0.25 cycles-per-pixel threshold.
Field testing was hampered slightly by using a host body without a viewfinder: external display screens have improved in quality enormously over the years but they are still difficult to use outdoors in bright sunlight. Consequently, some of the resulting pictures were out-of-focus due to the camera having chosen the wrong focusing point because it was not possible to anticipate this from the screen view.
The colour fringing that was seen during technical testing was also apparent in some real-world images but not often to an obtrusive extent.
Overall this lens promises a lot but has a flawed delivery: it works well but not faultlessly. There is the possibility that it might have performed better on a Panasonic body but the entire point of a standard lens mount is the ability to pair different lenses and cameras and if that cannot be done successfully then the standardisation is weakened.