September 22, 2015 at 10:33AM


Crop Factor Mumbo Jumbo – enlighten me please

I am making a move to Panasonic so coming from Canon background and yes I am a bit confused about the Crop Factor (from full frame and Crop 1.6 to MFT)

Also I have purchased Zhongyi Lens Turbo (EF to MFT /M43) and waiting for its delivery in mail.

Ok as per my understanding:

A normal 50mm F/1.4 lens for full frame will become 100mm F/1.4 on M43 /MFT mount while using a dummy / standard adapter that doesn’t have any glass.

Though when we use an adapter with Glass like Mitakon Zhongyi Lens Turbo that gives “Increases the angle of view by 0.726” then to get the actual crop factor and extra light stop info AS PER THAT ADAPTER CONFIGURATIONS we will multiply the 0.726 with the 100mm (50mm on MFT) and F/1.4

100mm x .0726 = 72.6mm or round would be 73mm
F/1.4 x 0.726 = F/1.016 or round would be F/1.0

Ok this is my understanding though I am quite sure I am not so right, please correct me and also is there any mathematical formula for such calculations?

If yes then please I would love to have that formula :)


1 Comment

You've got the math correct.

There is a crop-factor difference when shooting 4K video instead of shooting 1080 HD video. On the GH4 the crop factor for 1080 video is 2.0x, but when you're shooting 4K video it's roughly 2.3x, so 4K video crops a little tighter. In reality this crop-factor difference can be ignored most of the time because it's too small to really notice it.

September 22, 2015 at 2:01PM

Guy McLoughlin
Video Producer

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