MFT (Micro Four Thirds system) Camera

The Micro Four Thirds system (MFT) is a standard created by Olympus and Panasonic, and announced on August 5, 2008, for the design and development of mirrorless interchangeable lens digital cameras and camcorders.

I quite like the manufacturers agree to use the same standard, thus to avoid redundant same lens structure with competition in the market. Or in computer terminology, I like open source.

The M43 cameras I have: 

Olympus E-PL2 (M43 mount)
Cmos: 12.3 million pixels

Panasonic DMC-GF5 (M43 mount)
Cmos: 12.1 million pixels

The image sensor of Four Thirds and MFT/ M43 is commonly referred to as a 4/3" type or 4/3 type sensor
Since the M43 (Micro Four Third) camera has Crop Factor, therefore the old camera lens we use will be multiply as 2x.

The math has already been done for you, so if you fear math there is no need to run!  Search for the sensor type in your camera manual or do a Google search for the camera model that you own.  You can use the chart below to reference your sensor with its crop factor.

Sensor Size	Crop Factor Magnification
Full Frame	1.0x
APS-H	1.3x
APS-C, Nikon	1.5x
APS-C, Canon	1.6x
Faveon	1.7x
4/3rds	2.0x

So now that you have your crop factor, multiply the focal length of the lens you are using by the crop factor of your sensor.

For example, I use a MFT camera with a 50mm lens, thus you can see the result as followed:

 In the beginning, many people may think that if I have a 50mm lens, I have the crop factor magnification 2.0 x, thus it means my lens will be like a 100mm.

After you try, compare and study that, it is not true, actually, if you are using the above 50mm lens, you still have the same focal length, and you notice that the object will not be bigger or come closer to you. In stead, just like you take a photo at home, and crop it with your photo editor. This is the crop factor means.

Therefore, in the future, you have a full frame digital camera, the crop factor magnification is 1.0, then the 50mm lens will give you the full picture.