SVM
SVM — Stroboscopic Visibility Measure
Definition
SVM is a perceptual metric for the stroboscopic effect — the apparent stuttering or jagged motion of a moving object under modulated light. It targets the 80 Hz – 2 kHz band, where flicker is no longer directly visible but motion-related artifacts still are. SVM = 1.0 is the visibility threshold. Defined in CIE TN 006:2016.
Source overview
SVM is computed by applying a frequency-dependent visibility weighting to the modulation spectrum of the light waveform between 80 Hz and 2000 Hz, then taking a Minkowski-norm aggregate. SVM = 1.0 corresponds to the threshold of stroboscopic visibility for a typical observer; larger values indicate progressively more visible artifacts. CIE TN 006 specifies sampling at ≥ 4 kHz and observation windows of ≥ 1 second.
The underlying standard is paywalled or otherwise not directly reproducible here. The text above is a plain-language summary written by Slick Engineering — not a verbatim quote. Authoritative source linked below.
Technical detail
SVM cannot be computed from a 240 fps camera signal alone — Nyquist caps the camera at 120 Hz, well below SVM's lower edge. Reaching SVM requires a high-rate photodiode front-end. FlickerSpec's roadmap includes a purpose-built photodiode attachment to extend the app into the SVM band.
SVM is conceptually parallel to PstLM but for a different mechanism. PstLM addresses direct flicker visibility (≤ 90 Hz, where the eye still acts as a temporal low-pass sensor). SVM addresses stroboscopic effects (80 Hz – 2 kHz, where temporal aliasing of moving objects produces motion artifacts even though the steady-state appearance looks stable).
EU Ecodesign references SVM alongside PstLM. PAVM addresses an even higher band (above ~2 kHz) where eye-saccade-related phantom-array effects dominate.
Where it appears
- FlickerSpec Used here
Roadmap target. Requires the in-design photodiode attachment to bypass the camera's 120 Hz Nyquist limit. Not yet shipping.
Related terms
- PstLM
PstLM is a single-scalar perceptual metric for how annoying flicker from a light source is to a static human observer. PstLM = 1.0 correspon…
- PAVM
PAVM is a perceptual metric for the phantom-array effect — the chain of bright dots that appears when a viewer moves their eyes across a hig…
- IEC TR 61547-1:2015
IEC TR 61547-1:2015 is the international Technical Report that defines a standardized light flickermeter — a model of human perceptual respo…
- TLA
TLA is the umbrella term for visual artifacts produced by temporal modulation of a light source — covering directly-visible flicker, the str…