Sometimes, in Photoshop, my rulers are off centre:
In this case I have the Move Tool selected, I’ve just placed the image of the pin. It always seems to go away after a while, but I haven’t worked out what causes the rulers to snap back to where they should be ([0,0] at top left corner). Changing layers/tools doesn’t, nor does opening the rulers preferences panel.
Why does this happen?
How can I revert the rulers back when it does?
You simply changed the zero origin point.
Here is the movie oh how to fix it.
“You can change the rulers’ zero origin by dragging diagonally down onto the image. The ruler origin also determines the grid’s point of origin. To snap the ruler origin to guidelines or gridlines, choose View > Snap to Guides or View > Snap to Grid, before dragging.
To reset the ruler origin to its default value, double-click the upper left corner (origin) of the rulers.”