This ring is intended for mounting cameras at the output of CA-35 adapters (M54x0.75). The output of the ring is 2.156"-24tpi male imperial thread. Some American cameras, such as the SBIG and QSI models, have a front plate with a female thread measuring 2.156 inches in diameter (24 thread/inch). The optical path distance (OPD) of the ring is 3.4 mm, corresponding to the thickness required to mount a QSI WSG camera (to reach the conventional 56.2 mm behind the Takahashi CA-35 photo adapter).
It's very important to calculate the total length of the assembly of accessories in order to scrupulously respect the backfocus requirements of your instrument ; mechanical backfocus is the distance between the last mechanical bearing surface of the instrument, a field corrector or a focal reducer and the surface of your sensor. If in doubt, don't hesitate to contact your Takahashi dealer.
Caution! This ring is very specialized. Make sure your camera's output matches the imperial thread indicated. Incorrect assembly can damage the threads on your rings and cameras.
Designed by our team and manufactured in France by our partner mechanical workshop in Colmar, a specialist in high-precision machining in small series, this ring is made of aluminum and anodized in matte black.
| Characteristic | M54-2.156" ring (M/M), 3.4mm |
| Item number | OU013 |
| Design and manufacturer | Optique Unterlinden |
| Mechanical input | M54x0.75 male thread |
| Mechanical output | 2.156"-24 male thread |
| Optical path distance (OPD) | 3.4mm |
| Outside diameter | 65mm |
| Clear aperture | 45mm |
| Weight | 35g |
