Flare discussion seems to pop up quite often
I have read a lot of Stephen's writings and perhaps understand something. Perhaps not all.
Would the simpliest way to measure flare or get it's effect in the charts just expose two wedges. One without any optics (as contact print under the enlarger or using sensitometer) and another one by photographing wedge with normal coated lens.
Then just compare results?
If same exposure is done with couple of different lenses, it is easy to averaging flare.