Setting lensPosition to focus at infinity

I am creating a fixed-focus camera app with the focus distance at infinity (or at least 30+ feet away).

When I set lensPosition to 1.0, the images were blurry.

Some tests letting autofocus do the job showed a lensPosition of about 0.808 for my wide and telephoto lenses and 0.84 for the ultra wide lens did the trick. (iPhone 13 Max)

Will the lensPosition to focus at infinity vary between devices and lenses on that device?

Is there a way to determine the appropriate lensPosition at run time?

Looks like the optimal lensPosition changes over time. Could temperature change from device usage and ambient temperature changes affect the optimal lensPosition?

If so, it looks like I will have to recalibrate lensPosition on a regular basis.

Setting lensPosition to focus at infinity
 
 
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