The reasons I do it (1.3× in-camera crop) in my Nikon D7200 are severalfold:
* More reach (though I concede that doing so post has the same effect and may even save a wingtip or two, but since I am using a zoom lens - Tamron G2 150-600 - if I am on the ball I can zoom out and this shouldn't happen too often)
* Speed - I get an extra fps to take it from 6 up to 7 when in the 1.3× in-camera crop mode.
* Greater 'effective' focus point coverage over more of the (smaller active part of the) screen. In practice it just places a line border around the cropped area. Theoretically better AF.
* Smaller file sizes - beneficial on the camera's SD card, and in the amount of computer memory taken up.
* Metering - more options in practice in certain situations.
I may be crazy but I wouldn't be without it
I wish all cameras did it - it's such a simple thing to do. :cat:
Chosun :gh: