The Leo Triplet by Maxime Delin
The TSA-120 is equipped with an air-spaced ED triplet apochromatic lens with 120 mm diameter (900 mm focal length and F/D 7.5), mounted in a 3-element barrel. The latter ensures good stability of the optomechanical chain in the face of usual transport constraints and significant variations in operating temperature. It has a retractable dew shield and the length of the tube does not exceed 990 mm for a moderate weight of 6.7 kg.
The lens has been designed to achieve a very high level of performance in observation and photography. The chromatic aberration in short wavelengths (blue and violet) is reduced by one third compared to the old FS-102/FS-128 with Fluorite lens. The Strehl ratio at optimal wavelengths of human vision is almost perfect, at 99.2%, equivalent to that of the TOA series.
The TSA-120 is therefore a lightweight, compact and economical refractor, whose performance is similar to that of the TOA, Takahashi's flagship models and recognized as among the best in the world.
The addition of the optional field corrector allows native focus imaging. The TOA-35 reducer (F/5.25) makes it more comfortable in deep sky photography. All assemblies meet the rigidity and flexibility requirements of new imaging devices, such as digital cameras and the latest generation of CCD cameras.
| Characteristic | Takahashi TSA-120 refractor |
| Optical design | ED Triplet Super Apochromat |
| Lens cell | Air-spaced triplet. 3 lenses/3 groups. 1 S-FPL53 ED lens in the center |
| Coatings | Hard multicoatings |
| Diameter | 120 mm |
| At prime focus | |
| Focal length | 900 mm |
| Focal ratio | F/7.5 |
| Metal back distance | 227.5 mm |
| With TOA-35FL field corrector | |
| Focal length | 882 mm |
| Focal ratio | F/7.3 |
| Image circle diameter | 40 mm |
| Metal back distance | 117.5 mm |
| With TOA-35RD focal reducer | |
| Focal length | 672 mm |
| Focal ratio | F/5.6 |
| Image circle diameter | 40 mm |
| Metal back distance | 62.5 mm |
| With EXT-ED1.5X focal extender | |
| Focal length | 1350 mm |
| Focal ratio | F/11.3 |
| Image circle diameter | 44 mm |
| Metal back distance | 117.5 mm |
| Characteristic | Takahashi TSA-120 refractor |
| Length of the optical tube | 990 mm (870 mm with retracted dew shield) |
| Diameter of the optical tube | 125 mm |
| Diameter of the dew shield | 160 mm |
| Weight | 6.7 kg |
| Focuser | Rack-and-pinion |
Spot-diagram of Takahashi TSA-120 at prime focus
Spot-diagram of Takahashi TSA-120 with TOA-35FL field corrector
Spot-diagram of Takahashi TSA-120 with TOA-35RD focal reducer
| System-chart of Takahashi TSA-120 refractor | Télécharger |
| System-chart of Takahashi TSA-120 refractor with TOA-35RD focal reducer | Télécharger |
| System-chart of Takahashi TSA-120 refractor with EXT-ED1.5X focal extender | Télécharger |
| Instruction manual of Takahashi TSA-120 refractor | Télécharger |
gallery
The Leo Triplet by Maxime Delin
NGC6946 with 2017eaw supernova by Maxime Delin
Crescent Nebula by Maxime Delin
Around NGC891 by Maxime Delin
