MTF + lateral chromatic aberration from the four slanted quadrant edges
Auto-detected — the circular outline lets the SFRreg module locate each target, at any position or angle
Two constructions — chrome-on-glass for collimators and infinity-focus precision, or reflective for large-field, long-distance setups
Selectable 4:1 or 10:1 contrast — 4:1 follows the ISO 12233 method; 10:1 adds edge SNR for a more complete MTF map across the field
Built for hard geometries — long distance, ultra-wide FOV (>170°), multi-distance autofocus, collimator projection
Traceable on request — measured contrast, density and dimensions; CNAS L0579, NIST & NIM traceable
A single big flat chart can’t cover infinity focus or a 170° field.
Conventional SFR charts assume the whole field lands on one flat plane at a fixed distance. That breaks down three ways: at long focus distances the chart would have to be impractically large; past ~170° FOV the outer field never reaches a flat target at all; and autofocus testing wants several subjects at different distances in one frame. Scaling a flat chart up doesn’t fix any of these.
The SFRreg approach inverts it: use small targets, place several where you actually need measurements, and let the software register each one. The four-quadrant-in-a-circle pattern is what makes automatic detection at arbitrary position and angle possible.
| Test case | Flat single chart | QuadMark SFRreg targets |
|---|---|---|
| Long-distance / near-infinity focus | Needs an impractically large chart | Small target at distance, or projected by collimator |
| Ultra-wide FOV (>170°) | Corners miss a flat target | Place targets across the real field |
| Autofocus at mixed distances | One plane only | Several targets at different distances, one frame |
| Registration | Manual ROI | Auto-detected by the circle outline |
When a conventional chart is the right call: for a normal field of view at a fixed distance, an eSFR or slanted-edge chart is simpler — see our Chrome-on-Glass MTF Target and ISO 16505 chart. QuadMark earns its place on the hard geometries above.
Please fill out the form below or email us directly to sales@calibvision.com, our sales engineers will review your request and get back to you within 3 working days(typically faster).
