Probably for the reasons listed above, Sony produce lenses with wider field of view than officially nominated (and wider projection circle too) and crop them within processing pipeline in order to deal with short flange distance. This might be a reason why SEL 1018 covers even full frame from around 14mm.
他居然說 sel 10-18 mm 的等效寬度來到了14mm 而不是15mm 這蠻有意思的 所以其實這個鏡頭是9.5-18mm?