I'm getting an aperture reading of f5.6 at 30cm at ISO200 with the SB800 at minimum power. I can go to ISO800 noise free and 1600 with almost none so aperture setting is fine. 3200 starts getting noisy especially on a long exposure but there's definitely enough light, it's just a case of is 1/64000 quick enough.
ISP Airstream MK III No 15 which is a bit poorly at the moment and having a rest
AA Pro Sport + Ginb FT8 stock + Bushnell 4200 6-24x
EV2 MK1 + Leupold Comp 40x
Weihrauch HW100 KT laminate
SBFTC Competition Secretary