Zoom factor in confocal microscopy

Hello, I need help to understand how to calculate the zoom factor of a confocal microscopy image. Despite a lot of research and asking other people, I can’t find the answer. Let’s imagine that an image (with a scale bar of 20um) has been made with a x40 objective and an ON=1.3 , to observe an area of 250*250 µm when a zoom factor of 1 is chosen for the XY scanner.

My question is: what zoom factor was was used?


The thing is, the exact zoom factor number really doesn’t matter, and the number reported for “zoom” in different vendors software might be different. What does matter is pixel size, and the number of pixels (which together also determine your field of view)

In your example of 250 square microns, if the image was 1000x1000 pixels, then your pixel size would be 2.5 microns.

Those three pieces of information are all you usually need. If you’re trying to recover the exact zoom factor in the software, you might want to contact your microscope vendor

(Or look at the metadata in your captured image, then determine the zoom that gives you the same pixel size and number for the same objective)


As above. “Zoom” is just a unit-less number that is inversely proportional to scan angle.