This works reasonably well only on computers with a lot of memory as all images are loaded into page in full resolution, but even there it will be sluggish so be patient. It will not work well on smartphones or tablets. Select crop using mouse (the first corner of rectangle is defined by clicking and holding mouse button pressed, the second is defined by releasing button) or click on links for common crop locations:
Smaller: Center crop Top left DX corner crop Bottom right DX corner crop Top left FX corner crop Bottom right FX corner crop
Larger: Center crop Top left DX corner crop Bottom right DX corner crop Top left FX corner crop Bottom right FX corner crop

	Nikon 24-120vr	Nikon 18-35G
f/04.0
f/05.6
f/08.0
f/11.0