Nikon Z9 Mirrorless Camera - Manual (Page 155)

155 ISO Sensitivity
A The Photo Shooting Menu [ISO Sensitivity Settings] Option
ISO senstivity can also be adjusted using the [ ISO
sensitivity settings ] item in the photo shooting
menu.
A Hi 0.3–Hi 2.0
A setting of [ Hi 0.3 ] corresponds to an ISO sensitivity approximately 0.3 EV
higher than ISO 25600 (ISO 32000 equivalent) and [ Hi 2.0 ] to an ISO
sensitivity approximately 2 EV higher (ISO 102400 equivalent). Note that
pictures taken at these settings are particularly prone to “noise” in the form
of randomly-spaced bright pixels, fog, or lines.
A Lo 0.3–Lo 1.0
[ Lo 0.3 ] corresponds to an ISO sensitivity about 0.3 EV below ISO 64 (ISO 50
equivalent). [ Lo 1.0 ] is roughly 1 EV below ISO 100 (ISO 32 equivalent). Use
for larger apertures or slower shutter speeds when lighting is bright.
Highlights may be overexposed. In most cases, ISO sensitivities of ISO [
64 ] or
above are recommended.