
Surface Figure
Surface form tested by interferometry — PV/RMS values from the actual measurement.
1 · Thin rods amplify centration error. At Φ1.19 mm, a few arc-minutes of centration error moves the image noticeably, and stacked rods make it worse. The defect shows up in the assembled scope.
How HSD avoids it: centration is measured per ISO 10110-6 on a per-batch sampling plan, with measured values on the COA.
2 · There is almost no fit margin. −0.02/−0.04 mm on a 1.2 mm rod leaves no room for drift; a slightly oversize rod binds in the tube, an undersize one rattles.
How HSD avoids it: diameter is measured and recorded per batch, so drift shows at incoming inspection.
3 · The “manufacturer” may be a trader. When drawings move through several shops, no one can explain a yield problem.
How HSD avoids it: we are the factory — a 30-person precision optical workshop; your drawing stays with our engineers.
4 · Batch drift is invisible until assembly. A “within spec” COA hides lot-to-lot shifts that surface in the finished scope.
How HSD avoids it: every batch COA carries measured values — dimensions, centration, surface, method.
Ultra-thin relay sets have to be consistent rod to rod — same tolerance package, same measurement method, same COA format.
Production photos in the slim rigid scope range, labeled by diameter. Final specifications per your drawing.





Scope of supply: relay rods · slim relay rods (Φ1.19–1.96) · special diameter/length rod lenses · uncoated rod lens blanks — all make-to-print per your drawing.
| Item | Specification |
|---|---|
| Rod lens diameter range | Φ1.19–8.0 mm (this page: slim Φ1.19–1.96) |
| Diameter tolerance | −0.02 / −0.04 mm (fit) |
| Centration | ≤3′, tighter per drawing |
| Surface quality | 40/20 · MIL-PRF-13830B / ISO 10110-7 5/40-20 |
| Edge chipping | ≤0.05 mm, per drawing · ISO 10110-7 E 0.05 |
| Coating | BBAR 400–700 nm, R<0.5% (per drawing) |
| Glass | Per drawing: JGS1 / H-ZF / H-LAK / H-K9L / N-SK15; material certificates with each batch |
| Length tolerance | Per drawing |
On slim relays, the COA carries measured diameter and centration per batch, which matters more than a pass/fail line.
Have a slim rigid scope relay drawing? Send it and engineering will confirm the small-diameter process within 24 hours.
Send Your Drawing → Email [email protected]Application context
Slim rigid scope relays are the hardest to hold: Φ1.19–1.96 mm with tight diameter and centration. This page is the make-to-print route for those small relays.
Check on the drawing: small diameter, relay length and centration target; tolerances are confirmed before machining.
Yes, ≤3′ is held and measured per batch; tighter is possible per drawing.
Inspection & Metrology
Every batch is verified with interferometry, centration measurement and surface inspection. You get the actual measured values, not a “within spec” checkbox.

Surface form tested by interferometry — PV/RMS values from the actual measurement.

Centration checked on the centration station, typically ≤3′. The reading shown is from a real part — 2.02′.

Surface and edge quality inspected under a video microscope — scratch/dig per MIL-PRF-13830B.

A passing surface from a production run: PV 0.51λ, RMS 0.059λ. Rejects never leave the workshop.
Measured COA per batch — ask for a sample COA with your quote. · Learn how to read a surface map →

Small lens fixture measuring a local defect — PV 1.126λ.
Real measurement, kept on file. Your COA gets the same kind of data.
Watch rod lens grinding, polishing, centration measurement and final inspection in real time. All information shared during the tour is confidential — your NDA is welcome.
Schedule a Live Video Tour