On Sat, Sep 21, 2013 at 11:55 PM, Jaime Fernández del Río <jaime.frio@gmail.com> wrote:

I called it "spacing"... We should probably agree on a terminology library-wide. Incidentally, Josh, I called it "spacing" because of your SciPy talk. ;)

I know the real world is just a particular case we shouldn't be too concerned about, but isn't "sampling" or "spacing" basically what everyone else calls "resolution"?

Not exactly. The resolution is the minimum distance at which you can distinguish two points. If you upscale your image just by doubling up each pixel along each dimension, your pixel spacing/sampling is half but your resolution hasn't changed.

Similarly, stick a crappy lens in front of a sensor with very tiny pixel spacing, and your image resolution is limited by the lens, but your pixel spacing is unchanged.

Often, the sensor is the limiting factor, which is why we confuse the two. =)