LFingar wrote:
Your original question was not about the ability to frame, and using different shooting ratios definitely crops the sensor. Cropping the photo itself in PP is not something hidden in the camera, unless there are cameras where cropping can be done in-camera. I have no idea if there are.
The D7100 can crop in camera and also has a 1.3 crop mode you can set for faster bursts (at the lower cropped resolution of course).