When the Wrong Lens Hood is Used for the Same Lens..

Then vignetting or even dark corners will happen, for the case of the same Q 02 lens that is used on a Q/Q10 versus a Q7, see the following test:

http://bbs.kakaku.com/bbs/K0000264454/SortID=16353126/?Reload=%8C%9F%8D%F5
(in Japanese, Google translation to English Here.)

So, the new flower-shaped lens hood must be purchased separately for the old lens owners, otherwise the old lens hood cannot