We have an Axioscope microscope and planning to install a Nikon D5300 camera on top of it. The software I looked up, is DigiCam Control. The downside is we cannot add scale by default. The scale has to be calibrated for each slide. We capture lots of photos, so calibrating the scale each time we change the sample is waste of time. Does anybody have any idea regarding this issue?
Select the objectives you want to use on your microscope altogether with your camera. If the camera is not a permanent installation, ensure that the mount reliably establishes again and again the same position and alignment in respect to the optical axis of the microscope.
If not purchased altogether with the microscope (one other source), or lost during a move of the group you work in, see if an other group in your school active in microscopy may lend you one. It may be in geology, but equally in (analytical) chemistry, biology, histology, (laser) physics / optics, etc.
Take a good photograph with your camera mounted on the microscope observing the micrometer plate, starting with a low magnification. For once, you have to count the pixels to calibrate profiles for a given combination of objective, inner optics, and mounted sensor / camera. But today, you may get assistance by the software's plugin (example, documentation, tutorial video).