Here’s another example of the size advantage of the m4/3 system.
On the one hand, the new, superb, M.Zuiko Digital ED 300mm f/4 IS PRO Lens, on the other, the AF-S NIKKOR 600mm f/4E FL ED VR Lens.
Nikkor 600mm M.Zuiko 300mm Aperture: f/4.0 f/4.0 Angle of view: 4.1 deg 4.1 deg (12x magnification in both cases) Min Focus: 4.39m 1.4m (Oly focusses 3x closer) Retail Price: $12,500 $2,500 (Nikon is 5x the price) Size: 166 x 432mm 92.5x227mm (Nikon is 3x the size) Weight: 3.81 kg 1.47 kg (Nikon is 2.6x the weight)
They are both extremely sharp and well built pro-grade lenses. The Nikon costs as much as a car and you pretty much need a car or a mule to carry it around and a beefy tripod to use it. The Olympus is easily hand-holdable!
As they say, pictures are worth a thousand words:
Some will say: “yeah but I can use a 300mm lens on my FF D810 and crop it and I will get the same thing.” No you don’t. That 36 Mpixel sensor on your D810 becomes only 9 Mpixels at a 2X crop. That’s why a lot of Nikon wildlife shooters prefer the D7200 over a FF camera. But they still have to live with bulky, heavy, expensive FF lenses. Fine if you’re a pro with an assistant and lots of money, for the rest of us it takes all the fun out of photography.
So I’d say if you are a hobbyist or serious amateur who wants to get into wildlife photography, the m4/3 systems is the way to go.