I am choosing a camera and lens.

I want to buy a Canon EOS 650D, as this camera seems to be a good point of entry into the world of SLR.

My question is in the following:

The EOS 650D has a cropped sensor, so as I understand if I use Canon 50mm f/1.8 lens, the behavior will be quite different on a smaller sensor in comparison to full-frame sensor.

What is the relation between cameras sensor size and lens focal length?


The 650D has a "crop factor" of 1.6 so a 50mm will have about the same field of view of 50*1.6=80mm on a full frame.

This does not change the lens's focal length (or any other optical property) you get a "zoom in" effect because you only looking at the center of the image projected by the lens, that center part of the image is exactly what you would see with a full frame camera in the same exact situation if you cropped the picture in post processing and kept only the center area.


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