Methodology & limitations
The formulas, reference conventions, and unknowns behind every check.
Formulas and units
Effective focal length = native focal length × reducer or Barlow factor. Image scale = 206.265 × pixel size in µm ÷ effective focal length in mm.
Field of view = 2 × atan(sensor dimension ÷ (2 × effective focal length)), converted to degrees. Sensor diagonal = √(width² + height²).
Physical target = specified sensor distance + optional glass correction. Glass correction = thickness × (1 − 1 / refractive index). Spacing gap = physical target − summed component lengths.
Metric threads reconcile only when diameter and pitch agree and genders are opposite. Unrecognized labels stay unresolved. The first component’s telescope-side interface is not modeled.
A worked example
An 800 mm telescope with a 0.8× reducer has 640 mm effective focal length. With 3.76 µm pixels, image scale is 1.211806875 arcseconds per pixel. A 23.5 × 15.7 mm sensor frames approximately 2.10° × 1.41°. A 16.5 + 21 + 17.5 mm train totals 55 mm. A 2 mm filter with index 1.5 adds 0.6667 mm to the target only when that correction has not already been included.
Four checks, no aggregate score
Spacing compares the signed gap to your chosen tolerance. Thread checks compare adjacent, explicitly specified metric interfaces. Coverage compares sensor diagonal with the entered image circle. Endpoint checks look for Sensor at the end, not earlier in the train. None can guarantee physical or optical compatibility.
Evidence and uncertainty
A dimensional check is not a compatibility guarantee. Verify manufacturer reference planes, thread engagement, clearances, tilt, and optical performance.
Reproduce, compare, export
Save a named rig locally, pin an in-tab comparison baseline, or export the complete plan. The result JSON includes a method version, numeric units, checks, input plan, and limitations. Table CSV and printed reports include every component, not just the visible page.
No hidden catalog or commercial ranking
Examples are illustrative and are not verified product bundles. There is no live manufacturer database, recommendation ranking, or universal compatibility score. Advertising cannot change the calculations or suppress warnings.