I've tried to mfa this lens a few times and each time has resulted in no adjustments at all. As much as I'd like to make this lens sharper than it is I think the only way for me to do that is buy a big white! And that isn't happening any time soon.
Think your right there with the big white! when the Numbers come up. Lol
IMAGE LINK: https://flic.kr/p/TdMa2w Dartford Warbler by Colin Vanner, on Flickr
I thought that for a long time but I now think giving this lens what it needs it does as well as the big whites