Conclusion

The Panasonic LEICA DG VARIO-ELMAR 100-400mm f/4.0-6.3 ASPH Power O.I.S. is testament to the advantages that Micro Four Thirds offers in terms of size and weight - we can't think of another 200-800mm equivalent lens that weighs under 1kg! This makes it well-suited for wildlife and sports photographers looking for a relatively compact and light-weight all-in-one optic that's equally at home hand-held or on a support, especially as it focuses very quickly and reliably when mounted on the DMC-GX8 camera that we tested it with.

The built-in Power O.I.S system helps to keep things sharp throughout the zoom range, with performance at both the centre and edges of the image proving to be excellent even when using the lens wide-open. Chromatic aberrations are not really an issue, plus they can usually be dealt with in post processing, while distortion is automatically corrected on both Olympus and Panasonic bodies. Close-up performance is better than you would think based on the published minimum focus distance figure of 1.3m, and bokeh is pretty good thanks to the 9-bladed aperture. Dust and moisture resistance is the icing on the proverbial cake.

All in all, there's really not too much to complain about. There's a lot of plastic parts to help keep the weight down, and the lens does become somewhat unwieldy due to its extended length of 25cm when shooting hand-held at 800mm, but given that it will mostly be used on a tripod or monopod, we feel that this is an acceptable compromise.

Perhaps inevitably for such a unique lens, the price tag of £1349 / $1,799 is at first glance rather eye-watering, but given the incredibly versatile 200-800mm focal range that's on offer in such a compact package, bird, wildlife and sports photographers will probably consider it something of a bargain.

Ratings (out of 5)
Design	4.5
Features	5
Ease-of-use	4.5
Image quality	4.5
Value for money	4