A great advantage of Micro Four Thirds cameras is their small size and weight, but to maintain that advantage, you need small, light lenses. This wide-angle Panasonic Lumix G 14mm F2.5 ASPH Lens (28mm equivalent in 35mm) is about as small and light as you can get in this format--it has a diameter of just 2.19", length of 0.81" (from the tip of the lens to the base side of the lens mount) and it weighs a mere 1.94 oz.

Panasonic's Lumix G X Vario PZ 14-42mm f/3.5-5.6 Power O.I.S. Lens (Black) is a super compact retractable pancake 3x zoom lens (28-84mm equivalent in 35 mm and full-frame formats) for Lumix Micro 4/3 cameras that's only about the size and weight of the 20mm pancake lens. It's 2.4 x 1.87"/61 x 47.7mm (the short dimension shrinks to 1.05"/26.8mm when the power is off). It weighs just 3.35 oz/95 g. Not only is it small and light, this X lens has high performance specs like electric-powered zoom operation, autofocus during movie recording, nano surface coating that drastically reduces ghosting and flare, and Power O.I.S. (Optical Image Stabilization) for greatly improved image sharpness and blur reduction. Two ED lens elements compensate for chromatic aberration, and the silent design makes this an ideal lens for shooting video.