My eyesight is not good enough to see the focus zone on the LCD on the back of my DSLR; which is one of the reasons I use autofocus in the first place. Is there any allowance for users with reduced visual acuity in Spyder LensCal?
If you have difficulty determining what the results of your Spyder LensCal test shot are on the camera LCD, then download the image to your computer, and blow up the image to 1:1 on screen, centering on the intersection of the main target and the angled ruler. This should provide you with a very large view of the key location. You may then need to scroll vertically to see enough of the ruler to determine the focal zone.