Infinity adjustment (Expander only)

Your Expander/ Smart Expander^TM is meticulously fine-tuned with specialized test equipment at the factory to be able to focus to infinity for every combination of lens and camera body, and also to ensure optimal optical quality with CRC or floating-element lenses. No adjustments are necessary. Some older lenses which are out of tune due to age and some lower quality optics may not be able to focus to infinity with Expander/ Smart Expander^TM. It is possible to adjust Expander/ Smart Expander^TM to allow for infinity focus for these lenses. Remember, however, that "if it ain't broke, don't fix it." Do not attempt adjustment unless you are not able to attain infinity focus with your lens.

1. Mark the original position of the glass elements so that you could revert if needed.
2. Loosen the stop screw in a recessed hole next to the lens release button.
3. Rotate the glass elements.
4. Tighten the stop screw.
5. Test. When focused on an object that is very far away, the distance scale should point at the infinity mark. Caution: always tighten the stop screw before testing. 
6. Repeat adjustment as needed.

Notice that some autofocus zoom lenses are not true zooms but varifocals. The distance scale may not align exactly with the infinity mark at every zoom position. If that is the case, adjust the lens when zoomed to the middle of its zoom range first and then verify infinity focus at the wide and tele zoom positions.