Coarse-to-fine comparison
Progressively changing spacing shows where stripes lose reliable separation under a fixed imaging condition.
Sayce Logarithmic Targets
Compare detail along a frequency sweep.
Sayce-style logarithmic line patterns on glass for examining resolution over a changing range of spatial frequencies.
Product selection
What it is and what it does
The line spacing varies according to a defined logarithmic progression. A frequency scale or coordinate map links position on the chart to spatial frequency. The frequency law and orientation must be supplied with the artwork.
When to choose it
Choose a logarithmic chart when you want to inspect a frequency range in one field. A group-and-element USAF chart is preferable when the established procedure records discrete resolved elements.
Locate changes in reproduced detail
Repeated screening
A recorded pattern position can support before/after comparisons when illumination, magnification and processing remain consistent.
Specify the frequency map and usable span
| Choice | Selection basis |
|---|---|
| Position-to-frequency map | Use the exact artwork mapping rather than estimating frequency from the product photograph. |
| Useful frequency interval | Match the coarse and fine ends to magnification and sampling at the intended working distance. |
| Orientation and polarity | Align the frequency sweep with the intended test direction and illumination. |
Binary stripe contrast contains harmonics. A visual reading of a frequency sweep is not directly a sinusoidal MTF curve.
Distinguish stripe contrast from MTFWhere this product is used
A changing spatial-frequency range within one field.
Inspection and delivery
Verify line spacing at defined sampling positions and check the correspondence between labels and artwork.
The glass pattern is supplied with its defined frequency progression, orientation and substrate format. Pattern labels are checked against the selected artwork.
Common questions
Can the pattern be resized freely?
Resizing changes all physical spatial frequencies. The frequency labels must be recalculated whenever the artwork scale changes.
Selection notes
Sayce logarithmic targets vary stripe scale along the pattern for evaluating changing spatial detail.
Use the frequency-position mapping of the selected artwork and record magnification. Plate outline does not define the finest frequency.
Information for your inquiry
Artwork reference, frequency map, labels, polarity, active area and substrate.
Can I infer the finest frequency from glass size?
No. The outline defines mounting and available area. The stripe artwork and its scale mapping determine the frequency range.