Infinity-conjugate lens checks
Place the chart in the collimator focal plane to present its pattern as a distant object to the tested optics.
NBS 1963A Five-Bar Resolution Targets
Five bars for an infinity-conjugate test.
NBS 1963A five-bar resolution targets for ISO 3334-style readings, microscope and scanner testing, and infinity-conjugate collimator setups.
Product selection
What it is and what it does
NBS 1963A uses five long parallel bars in horizontal and vertical groups. The approved artwork uses a long-bar ratio of about 24:1 and discrete labelled fields. In a collimator setup the target is placed at the focal plane, so the physical cycles/mm value must be converted into an angular result using the collimator focal length.
When to choose it
Choose it when the procedure calls for an ISO 3334-style five-bar chart, a standardised reading across batches, or a physical target in an infinity-conjugate optical bench.
Test distant-object imaging with a collimator
Five-bar interpretation
The accepted group must retain five separate bars and four gaps. Record the physical chart frequency and the collimator geometry together.
Choose the chart and its optical arrangement
| Choice | Selection basis |
|---|---|
| Pattern version | Use the five-bar layout and frequency progression specified for the test, rather than substituting a three-bar NBS chart. |
| Collimator relationship | Target frequency and collimator focal length together define the angular scale presented to the instrument. |
| Field and mounting | Match the active field, polarity and substrate format to the focal-plane holder and illumination. |
Formats and pattern options
Five-bar circular format
Ø30 mm
A 30 mm circular five-bar target for a compact holder; confirm the chart scale and active field separately.
Five-bar pattern reference
Dimensions to drawing
A reference view of the five-bar artwork. Physical frequency and substrate dimensions come from the approved drawing.
Where this product is used
Multi-orientation five-bar fields for comparing resolved detail.
Inspection and delivery
Inspect bar count, line width, gap width, field label, orientation, edge quality and active-area defects. For infinity-conjugate use, record the artwork frequency, collimator focal length and any coordinate or certificate data included in the agreed delivery scope.
The supplied component is the five-bar glass target in the selected artwork and substrate format. The collimator and tested lens are parts of the user’s measurement setup.
Selection notes
NBS 1963A five-bar targets provide differently oriented line groups for comparing imaging resolution.
Use the frequency and angular-scale mapping of the selected NBS artwork. For infinity-conjugate testing, record collimator focal length and imaging conditions.
Information for your inquiry
Artwork reference, frequency range, polarity, substrate outline and collimator setup.
Can I use the USAF group formula?
Use the NBS artwork's own labels and frequency map. The USAF three-bar group formula applies to the corresponding USAF pattern.