Stereoscope image scale

Obtain image(s) of the micrometer slide

Use the specialized slide with a micrometer (small ruler)
Obtain an image of the micrometer at the exact same magnification as your image
Take a photo of the left side of the ruler where the increments are smaller
- 1mm in 0.01mm divisions, 5mm in 0.1mm divisions; 25mm in 0.5mm divisions

Set the scale in Zen (work in progress)

Open the scaling dialogue box at the very bottom left of the program window
Create new scaling (Interactive calibration)
Press ‘No’, when asked if you’d like to overwrite any existing scaling
You will be prompted to draw a reference line on the micrometer image (it might be hidden under the scaling dialogue box
Add the known length and units, and denote the magnification in the name
To assign the appropriate scaling to an image, select from the ‘Available Scaling’ drop down menu
- Click on the gear icon to the right of the name
  - Choose ‘Assign scaling to image’

Set the scale in Fiji/ImageJ

Open the image of the micrometer
Select the line tool to measure a portion of the micrometer
Click once at the beginning point of where you want to measure, drag the mouse to the end point, and release.
Analyze > Set Scale
“Distance in pixels” should be automatically populated with the number of pixels in your line.
Input the known length of the portion of the micrometer that you measured into the “Known distance” field.
Enter mm into the “Unit of length” field
Click the “Global” checkbox to apply the scale to all images that you open in the session.

Add the scale bar to your image

Keith R. Porter Imaging Facility