olemus
(a) optikas üldiselt
= out of focus
https://st2.depositphotos.com/7570388/10703/i/950/depositphotos_107031820-stock-photo-blur-or-defocus-image-of.jpg
Wiktionary:
noun
2. (optics) the distance by which the focal point is in front of (positive defocus) or beyond (negative defocus) the image or target surface
https://en.wikipedia.org/wiki/Defocus_aberration
https://en.wikipedia.org/wiki/Shallow_focus

(b) ISO/IEC 29794 (biomeetria):
kujutise kahjustus, mille põhjustab
iirise paiknemine kaamera optilisel teljel
väljaspool parima teravuse pinda,
enamasti teravuse langus (hägusus) ja
kontrasti vähenemine
=
image impairment due to the position of the iris along the optical axis of the camera away from the plane or surface of best focus, generally resulting in reduced sharpness (blur) and reduced contrast
https://www.nature.com/articles/s41598-020-65151-5