For better functionality on mobile devices, I have added a pair of arrow buttons to the lens comparison tools listed below.
When comparing two lenses in these tools, the mouseover functionality still works as it did before (and still does not work on mobile devices). The new buttons, located between the lens names near the top of the pages, can now be clicked to select the lens results to be displayed. Mobile device users should find these buttons to work for them. The results shown after clicking on these arrow buttons will hold until the other button is selected (or a mouseover is used).
ISO 12233 Resolution Chart Comparison
Vignetting Test Results Comparison
Lens Flare Test Comparison
Lens Distortion Test Comparison
As always, suggestions are appreciated. Thank you to those who made this suggestion.