Originally posted by zzeitg It does not look that easy to me (not something I'd do with any lens in warranty). I'm wondering if I need it at all when I use the AF button to confirm focus?
It depends. If the scale is not too far off it is not really a problem, although extreme wide angle lenses are not too easy to focus manually and the AF confirmation is also not too reliable. Combined with the wide depth of field it makes sense to use the scale. Some copies have been reported to be quite a bit off. Note that the lens is not meant to have a hard stop at infinity; the mark is always before the hard stop (that is, if it works like my Samyang 16mm, which I assume it does). Try and focus at some distant object and see if your setting is close to the infinity mark.