MAKING SCALE BARS USING PHOTO SHOP:
1) Before starting make sure that you have worked out:
a. The pixel length for the objective, microscope etc you are using.
i. This is done by: using a stage micrometer (a slide that has a
calibrated measurement on it.)
ii. Take an image and using Photoshop measure the length of the
known spacings in pixels. Calculate the value for one pixel and
you have the pixel length.
2) Open your image in Photoshop.
a. Go to Layer: New: layer.
i. Name the layer: scale bar
ii. In the layer window you will see your new scale bar layer.
3) Select the line tool.
a. At the top of the screen there will be the properties of your line.
Change the thickness of the line using the weight option in pixels.
Around 10 pixels is usually ok.
4) In the info window in the bottom left hand corner there is a little cross. Right
click on this and make sure that the marker is measuring in pixels. (If you can
not see the info window go to Windows and choose show info)
5) On your image, draw a line.
a. Click where you want the line to start and hold down the shift button to
get a straight line.
b. The length of the line in pixels will determine the value of the line in
micrometers. Calculate the length of the line that you want that is
reasonable for your image. Usually for 60x objective ~ 40 um.
6) You can use the select icon (arrow) to move the line around the image after
you have drawn it.
7) Now select the text button. Click on the image just above and in the center of
the line you have drawn. Type in the length of the line in microns.
a. The micron sign is on the text type (symbol T1) and type the letter M
on the keyboard.
b. The text creates its own layer. You now have three layers on your
c. You can move the text around the image using the select icon.
8) Once you have the line and text in the right position you can combine two
layers into one.
a. Do this by making the image invisible (click on the eye in the layers
window) so that you cannot see the image.
b. Choose Layers, Merge visible.
9) You now have two layers.
10) You can save this image with the two layers. You can only save it as a PSD or
a Photoshop image. You have the option to save as tiff, however all of the
information will not be saved, meaning that all layers will not be saved.
a. You should do this if you which to use the scale bar again for another
image. The scale bar and text can be selected and dragged and dropped
onto a new image. You can use this for all images captured using the
same microscope and objective.
11) However to save the image as a tiff, you will need to merge all layers in your
a. Do this by going to layer, then Flatten image or Merge down.
12) If you now say save as, you have the option to save as a tiff etc. without any