Methods to determine the size of an object in microns

Mathematically

Pixels on our CCD are 6.45um. The size (in microns) of one pixel in an image will depend on how much the image was magnified before reaching the CCD:

$\mbox{Pixel size} = \frac{6.45um}{\mbox{total magnification}}$

Assuming that the magnifier is at position 1x (not 1.5x), this formula gives us:

60x  : 0.1075 um/pixel or 9.30 pixels/um 40x  : 0.1613 um/pixel or 6.21 pixels/um 20x  : 0.3225 um/pixel or 3.10 pixels/um 10x  : 0.645 um/pixel or 1.55 pixel/um