Takahashi's TOA series of refractors feature a unique Ortho-Apochromatic triplet design which offer the highest possible correction of any refractor on the market. This special optical configuration based on a highly air-spaced triplet completelyeliminates spherical aberrationwhile having the best chromatic correction in the Takahashi range. Withtwo S-FPL53ED elements, theair-spaced tripletlens cell has a Strehl ratio of 99.8%at the optimal wavelengths of human vision.
The Takahashi TSA-120 is an apochromatic triplet refractor with exceptional correction for observation and astrophotography. With one S-FPL53 ED element, the air-spaced triplet lens cell provides similar performance to their flagship TOA series with a Strehl ratio of 99.2% at the optimal wavelengths of human vision.