The visible parts of an object, and it's parts with relation to each other, change as it moves through our visual field.
Consider a plus sign +
floating in front of a minus sign -
.
If you were directly in front of that, you'd see +
directly in front of you (as it would hide the -
).
If you moved to the left, you'd see -+
to your right,
And if you moved to the right, you'd see +-
to your left.
If you take a photo and crop it, not preserving the center, you can create an image that cannot be experienced.
e.g. a -+
directly in front of you, or a +
to the left.
For this reason, I personally feel that cropping which fails to preserve the center of a photo is a "sin" of cropping.
Does this sin have a name, and does the practice of avoiding it have a name?