Nikon LS-3510 Software Reference Manual page 40

5-8
First, you should select the crop with the mouse:
Fig. 33
The resolution specification items may now look like this for the above crop:
Fig. 34
Now, check the Proportions checkbox. This will allow you to enter a height
or width value without changing the aspect ratio. Type 8 into the width edit field.
The resolution specification items will look like this:
Fig. 35
Note the little lock in the previous figure. That means that any changes in
width will cause a change in height to keep the scan rectangle in the same aspect
ratio as before. That is what locked proportions means. The value in the height
edit field changed to 6.4.
Software Reference for Scanners
Mouse Selected Crop
Specifications for Mouse Selected Crop
Lock Proportions
Using The Macintosh Scanner Plugin