Infinity Compensation Mark
![](/library/CANON/CITS_TECH_SUPPORT/Camera/Lenses/EF%20400mm%20F2.8L%20IS%20III%20USM/infinitycompmark.png)
To compensate for shifting of the infinity focus point that results from changes in temperature, there is a margin at the infinity (∞) position.
The infinity position at normal temperature is the point at which the vertical line of the distance scale
![](/library/CANON/CITS_TECH_SUPPORT/Camera/Lenses/EF%20400mm%20F2.8L%20IS%20III%20USM/mark.png)
mark is aligned with the distance index.
![](/library/CANON/CITS_TECH_SUPPORT/Camera/Lenses/EF%20400mm%20F2.8L%20IS%20III%20USM/warning.png) |
- For accurate focusing in MF on subjects at infinity distance, look through the viewfinder or at an enlarged image on the LCD monitor* while turning the focusing ring.
* On cameras capable of Live View shooting
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