To help you carefully collimate your Cassegrain telescopes, such as Dall-Kirkham, Ritchey-Chrétien or CDK reflectors, Takahashi offers a special tool: the collimating scope. Its purpose is to help you adjust the secondary mirror as precisely as possible; this generally hyperbolic mirror needs to be oriented in the best possible way.
For the collimating scope to be usable, the secondary mirror must be marked. The microscope lets you "zoom" in on this mark, so as to align it with the focuser. You don't have to act on the primary mirror. The collimation scope can be used on Takahashi CCA-250, Mewlon-250CRS and Mewlon-300CRS reflectors, but not on Mewlon-180 and Mewlon-210 ones whose secondary mirrors are not marked. It is also compatible with Cassegrain and Ritchey-Chrétien GSO optical tubes, as well as Planewave, RCOS, etc. telescopes.
Three types of mounting are possible, depending on instrument manufacturer and model.
For Takahashi Mewlon-250CRS and Mewlon-300CRS tubes, the collimation scope is screwed directly onto the M36.4 thread of the #14 ring of the eyepiece holder.
On Takahashi CCA-250 reflector, the collimation scope is screwed onto the M36.4 thread of the no.14 ring, at the output of the no.12 visual adapter.
For compatible telescopes of other manufacturers which secondary mirror is marked, we have designed a 50.8 mm adapter that fits directly into the instrument's eyepiece holders.
| Characteristic | Takahashi collimating scope |
| Item number | TKA00443 |
| Input mechanical interface | M36.4x1 male thread |
| Output mechanical interface | - |
| Size | Length : 210 mm. Diameter : 40 mm |
| Weight | 235 g |
