Scale Bars

There are two ways to add scale bars to 2D images.

Quick Note: Note the magnification you are using on the MP-E 65mm 1-5x to apply scale bars within that range. When using the MP-E 65mm lens, ensure the yellow xX line is just slightly, but completely revealed in order to properly match a scale bar (see photo below).

As a helpful reminder, I always insert the magnification using not the filename.

Method 1: The first method of applying a scale bar is to create the file yourself using photoshop. This method has a few nice perks:

perk 1) Have confidence your scale bar is correct
perk 2) You can shoot at any magnification you would like as long as you have a unit of measurement in the background
perk 3) The scale bars are forever available in photoshop for future use.

Macroscopic Solutions calibrates scale bars using the TedPella 5mm ruler: http://macroscopicsolutions.com/product/5mm-scale-027-calibrated-to-0-1mm-5mm-range/#product_images%5Bgrouped%5D/0/

Step 1: Insert an image into photoshop with a unit of measurement in it. I’m going to use an image where a scale bar has already been applied on an image taken at 5x with the MP-E65mm. You can pretend the scale bar is a ruler or measurement grid in the background.

Step 2: Use the ruler tool to measure the length of the line (1mm) in pixels. The ruler tool can be accessed by right clicking the eye dropper tool (figure 1).

Step 3: Once selected, click and drag the ruler tool over the length of known measurement. In this case, the line indicates 1mm. The length in pixels is revealed in the toolbar as L1 (circled in red in figure 2). In this case, there are precisely 765.38 pixels in 1 mm.

Step 4: Go to “Analysis” > “Set Measurement Scale” > “Custom”
a) Insert the “pixel length” (765) rounded
b) Insert the “logical length” (1) representing no. of millimeters
c) Insert the “logical units” (mm) representing units (could be micrometer, millimeter, etc.)
d) Click “Save Preset” and name a unique identifier so that you can avoid these steps in the future. I’ve named this one “Forum Test.” Then press “OK” and “OK.” (figure 3)
Note: If the ruler you have is 5 cm… you can find the pixel length of the 5 cm rule and enter 5 cm.

Step 5. You will now see the calibrated scale bar in the list under “set measurement scale.” Please make sure the scale bar you just created is checkmarked.

Note* In figure 4. you will see a list of scale bars made by me at each level of magnification I use specifically with the Canon 6D (5472×3648 pixel resolution). If you change camera bodies or use a different pixel resolution, you will need to repeat steps 1 – 4. Please ask questions below if you need me to explain further.

Step 6. Apply scale bar by going to “Analysis” and “Place Scale Marker.” Choose your color, font size and font. Click “OK”. (figure 5).

Step 7. A new scale bar will emerge as a layer that you can further manipulate if you wish (figure 6)

Method 2: This method is nice because you do not have to worry about changes in resolution, you simply have to match the size of the .psd overlay file to the overall size of the image.

The scale bars and an instructional video can be downloaded and found using the following link.: http://macroscopicsolutions.com/product/psd-overlay-files-for-mp-e-65mm-1-5x-lens/

I you are a client of Macroscopic Solutions, contact us and we will provide you with these .PSD overlays without charge.