Tak TOA 645 Flattener 0.99X for TOA-130

The newly designed 645 flattener features two fully multi-coated lens elements in two groups and provides outstanding correction out to a 60 mm image circle. Being designed specifically for the TOA-130N and TOA-150B, RMS spot diameters of 1 micron on-axis are achieved. At a 30 mm diameter image circle, the RMS spot diameter is 2 microns, and at 43 mm it is 3 microns. Even out to the full diameter of 60 mm, the RMS spot diameter is 5 microns. With these spot sizes, images are nearly aberration on even the newest small pixel sensors.   The flattener is available in two versions, one for the TOA-130N and one for the TOA-150B. Optically, the two versions are identical, with the only difference being the length of the spacer on the camera side of the adapter. Unlike the old 67 flattener, the 645 flattener has an M72 thread on the telescope side, meaning it can be used not only on the TOA-130NFB, but on the TOA-130NS as well.   For the TOA-130N with the included adapter ring (L), the flatten