...
At the end of the church ceremony, he tracks me down outside and asked if he could borrow my 85L to shoot portraitures of the B&G...

I've been following this thread..
I agree, the pro's request was stupid:
1. I would never consider borrowing/lending a valuable lens to/from a stranger.
2. He is doing a wedding, if he has never used an 85L, it would be a mistake to cut his teeth on the B&G portraits.
The benefit the 85L provides over his own equipment is the shallow DOF and accompanying beautiful blur. That shallow DOF can also be a challenge (especially at first) and is the reason why he should not use it w/out experience for wedding shots. (I am assuming he never used one before).
But I am also always surprised when I see, in this forum, the "equipment doesn't matter" kind of comments. The 85L does have some clear (actually, blurry
) advantages over the 24-70 and I can understand why he may have wanted to give it a try; it was just stupid (IMO) because of the circumstances (i.e., stranger, wedding).



