When I first started looking around for an IR modified camera, I read that some lenses were better than others.
Somewhere I read that the old Nikon 43-86mm/3.5 was a good one for IR
I have no idea where I read it, and cannot find it again.
This lens has a bad reputation by some accounts, but the first version is allegedly worse than the second version
I picked up an immaculate version two off evilbay for less than $50 delivered a while back.
Anyway, with my go-to lens for this camera (m.zuiko 9-18mm) off on it's second holiday to the Olympus repair centre, I had a play with a few old lenses.
I was quite impressed by this old girl...
At 43mm
At 86mm