Calibrating a Microscope

Procedure

1. Get an iPod with a retina display and place it under a microscope
2. Using a microscope camera, take a photo of the screen at 10x magnification, using the application ImageJ.
3. From the documentation, we know that the size of a pixel is 78 µm, corresponding to 326 pixels per inch.
4. In ImageJ, use the line tool to measure five iPod pixels, and then look at how many pixels of the camera it corresponds to.
5. Then, go to analyze, and choose set scale.
6. In set scale, choose the first box and type how many camera pixels the five iPod pixels are.
7. In the second box type how many µm the five iPod pixels are (390 µm).
8. Leave the third box alone and in the fourth box write the unit of measurement which is µm.
9. Then you can also place a scale bar by going to analyze--tools--scale bar and typing how long the scale bar should be, where it should go, and much more.

ImageJ can be found at:

http://rsb.info.nih.gov/ij/download.html