The CA ring 128 is designed to adapt the Takahashi FC/FS Multi-Flattener for use with the FS-128 and FS-152 telescopes.
Message from Takahashi:
We are releasing multiple CA ring corresponding to old products for FC/FS multi-flattener 1.04 × which has received popularity. The FC/FS multi-flattener 1.04 × consists of two lenses, the higher order field curvature can be reduced by giving a difference in the refractive index between the lenses, the red and blue halos of the central image are also reduced It is a flattener that can obtain a sharper star image.
This flattener is designed for models equipped with Takahashi's two-piece ball flow objective lens, so it can be used for most models of the FC/FS series including old products, and corrects field curvature can do.
The compatibility with FC-50, FC-60, FC-65 is particularly excellent in the old product, and in the case of FC-50 it is nearly astigmatism, within 5 microns to the full size periphery with RMS-SPOT .
However, SKY 90 does not adapt even for the same old product's Flow Light 2 balls, as the aberration correction state of the objective lens is different from FC/FS type.
To use it, we prepared for each model, we need an optional multi CA ring. The multi CA ring released this time is four kinds corresponding to 8 models that have finished FC/FS multi-flattener 1.04 ×.