Using the Infinity Distance Mark
EF100-400mm F4.5-5.6L IS USM
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To compensate for shifting of the infinity focus point that results from changes in temperature, you can rotate the distance ring slightly past the normal infinity focus mark.
- The infinity position at normal temperature is the point at which the vertical line of the L mark is aligned with the distance indicator on the distance ring.
- For accurate manual focusing on subjects at infinity distance, look through the viewfinder while rotating the focusing ring.