Unable to change numbers in Set Scale dialog



Hello @Herbie

I saw you are so helpful with this so I thought you might provide some insight to my problem similar to Abdelhady.
Attached below is my aorta in H&E staining, 40x. I captured the image using Olympus microscope in JPEG, not knowingly that TIFF is actually the best format for ImageJ, hence the unit given is in pixels instead of micrometer.

I want to measure the intima thickness, shown with black line, it starts at the first upper layer to bottom lowest layer.

Tried to calibrate by following exactly like Getting Started page instructed, but I just CAN’T change any number or unit in Set Scale dialog box, nothing happened.

Measuring Thickness

Good day,

next time please create a new thread!

I guess you are using a machine with macOS “High Sierra”. There are a number of problems associated with this OS-version and Java. Please consult the docs:




Hi @Herbie @nur_hani_suhaimi,

I agree with @Herbie that this is a separate problem from the initial topic, so I split it into a new thread.

EDIT: See this thread on a set scale dialogue issue for High Sierra.


Thank you @Herbie @Sverre for the clarification. never thought that High Sierra is the root cause of the problem.


Unfortunately there seems to be a lot of issues with this OSX update and ImageJ/Fiji. Were you able to resolve the issue by updating Fiji/ImageJ?


My last resort is to use department’s Windows computer & I just went with it. My work is settled at last.